munities of their putative Spanish native range. In-
vaded California grasslands were more similar in
species composition to Spanish grasslands than
some Spanish grasslands were among themselves.
In California, non-native species had more resource
acquisitive traits than co-occurring native species.
In Spain, species that invaded California were also
more acquisitive than species not known to be in-
vasive somewhere. However, trait differences were
not as large as in the introduced range of Califor-
nia indicating that they might have increased their
competitive ability. This might also reflect preadap-
tation of the entire species pool to the management
practices that have taken place in Europe for millen-
nia. Trait differences between native and non-na-
tive species were also dependent on environmen-
tal conditions indicating that niche differentiation is
subject to the influence of abiotic and biotic filters
encountered in the new region of introduction. Our
results show that differences between co-occurring
native and non-native species are context depen-
dent and that a correct interpretation of filtering
processes in community assembly requires a bio-
geographical perspective.

S.243.2 Buzz pollination in
invasive plant populations

Mario Vallejo-Marín¹

¹Plant Ecology and Evolution, Department of Ecolo-
gy and Genetics. Uppsala University, Sweden.

Plant populations that colonise and spread be-
yond their native range might face reproductive
challenges arising from the scarcity of con-specif-
ic mates and suitable pollinators. For this reason, it
could be expected that outcrossing plants with spe-
cialised pollination syndromes should be at a par-
ticular disadvantage compared to similar species
with generalised pollination or capable of shifting to
autonomous self-pollination. Here, I discuss the case
of species that have managed to successfully colo-
nise and spread beyond their native range despite
having a functionally specialised pollination system
that relies on vibration-producing bees to release
pollen, i.e., buzz pollination. Buzz pollinated plants
usually have tubular-shaped anthers that open
only through small apical gaps or pores (poricidal
anthers). Reducing pollen limitation in successful
invasions of buzz pollinated plants could be facili-
tated by modification of poricidal anthers to release
pollen in the absence of pollinators, thus promoting
autonomous selfing. Alternatively, buzz-pollinated

plants may be able to recruit taxonomically differ-
ent, but functionally similar types of buzz pollinating
bees in the introduced range. Buzz pollinating bees
are geographically widespread and can adapt be-
haviourally to deploy vibrations in many types of
flowers. Thus, we expect that invasions of buzz pol-
inated plants often occur by recruiting non-native
buzz pollinators rather than by transitions to in-
creased autonomous selfing.

S.243.3 Adapting plant
genetic diversity to climate
change along a continental
latitudinal gradient

Ivan M. De-la-Cruz¹, Anne Muola²,³, Johan
A. Stenberg¹

1 Swedish University of Agricultural Sciences, Alnarp,
Sweden. 2 Norwegian Institute of Bioeconomy Re-
search, Tromsø, Norway. 3 University of Turku, Turku,
Finland.

Climate change, including increased temperature and altered precipitation, is likely to advance spring phenology and cause poleward range expansions of many plant species but also herbivores. This is likely to profoundly alter both abiotic and biotic natural selection on - and evolution of - plant traits in local plant populations. We used latitudinal gradient across the continental Europe as a 'space-for-time approach' to mimic future climates, i.e., current southern ecosystems represent the abiotic and biotic conditions of more northerly habitats in the future. Genotypes of the woodland strawberry (Fragaria vesca; Rosaceae) originating from this gradient were replicated to five separate experimental sites placed across a north-south latitudinal gradient within Europe. Additionally, at each site, half of the plants were exposed to a drought treatment. By using this framework, we studied biotic and abiotic natural selection on plant traits. Herbivore pressure was higher at mid-latitudes compared to the extremes of the latitudinal distribution of F. vesca in Europe. In the Arctic, F. vesca genotypes from southern and central Europe had delayed flowering onset compared to when they grew at more southern sites. However, northern F. vesca genotypes showed remarkable flexibility in their ability to time flowering onset according to local conditions. Plants subjected to drought experienced more herbivory, accelerated flowering in most of the sites, and grew larger and produced more fruits and runners at
<figure><img src="image_561.png" /></figure>

some sites. However, at the driest site, there was a decrease in fruit production and chewing damage. Indication of a trade-off was found between reproduction, growth, and defense at several of the sites, being evident almost only under drought. Our results provide timely insights on how plant adaptations to climate change should be studied in combination with plant adaptations to biotic interactions, which also are affected by changing environments.

### S.243.4 The specialized buzz pollination syndrome poses a partial barrier to plant invasions

Laura Lopresti¹², Lori Lach², Daniel Montesinos¹,²

1 Australian Tropical Herbarium, James Cook University, Cairns, Australia. 2 College of Science and Engineering, James Cook University, Cairns, Australia.

The missed mutualist hypothesis proposes that when a species is introduced into a new range it may leave behind its mutualistic partners, which can lead to reduced fitness and prevent the species establishing and becoming invasive. Further, it has been hypothesised that specialist mutualisms are likely to impede invasion success due to the difficulty of attracting new specialist partners. The buzz-pollination syndrome encompasses specialised floral traits that restrict pollen access and requires a specialised bee behaviour for efficient pollen extraction. Yet, many invasive plants globally exhibit the buzz pollination syndrome. We used the buzz-pollination syndrome as a model to test the hypotheses that: (1) plant species exhibiting specialised pollination syndromes are underrepresented as invasive species, (2) species with specialised pollination syndromes that have become invasive can reproduce in the absence of specialist buzzing pollinators. Our review of global invasive species found evidence for buzz-pollination in 1.8% (82/4,630) of invasive angiosperms, which is an underrepresentation of the proportion of angiosperms that are estimated to exhibit this syndrome (6-10%). Most invasive buzz-pollinated plants are genetically self-compatible (97%), but only 43% can set fruit in the absence of a pollinator. We undertook assessments of the breeding system and pollinators of a highly invasive weed across the world's tropics, *Senna obtusifolia*, in its native and invasive ranges. *Senna obtusifolia* is self-compatible and can set seed in the absence of pollinators. An

analysis of the behaviour and pollen loads of floral visitors demonstrated that the specialist behaviour is not required to extract pollen from *S. obtusifolia*, depicting alternative foraging behaviours can be used to extract pollen from plants that exhibit the buzz-pollination syndrome. This is important where buzzing pollinators may be absent or not attracted to newly introduced plant species, potentially enabling invasions for plants that exhibit the specialised buzz-pollination syndrome.

### S.243.5 What processes maintain the species diversity of annual plants in arid environments?

Peter Chesson¹,²

1 Department of Ecology and Evolutionary Biology, the University of Arizona, USA. 2 Department of Life Sciences and Center for Global Change Biology, National Chung Hsing University, Taiwan.

Arid regions support diverse floras of annual plants. Such regions are characterized by highly variable rainfall. The flexibility of the annual plant life cycle is suited to such variable conditions because annual plants can take advantage of short periods of rainfall to germinate, grow and set seed. A striking feature of such annual plant communities, however, is high levels of temporal variation in species composition. This variation can be traced to species-specific germination requirements, especially sensitivity to temperature when rain falls, which differs between species. More than 70 years ago it was suggested that temporal changes in composition have an important role in maintaining the species diversity of these systems. These annual plants are generally assumed to compete intensely for soil moisture and nutrients, but temporal variation in composition means that the various species are competing for these resources at different times. Many observations and experiments have confirmed these patterns, yet definitive tests that temporal variation maintains diversity is lacking. Such tests use covariance measures to test whether temporal patterns in germination and growth do, over time, intensify average intraspecific competition relative to interspecific competition, thus promoting species coexistence. However, such systems are commonly subject to high levels of seed predation from rodents, ants, and birds, which can limit competition, undermining temporal variation as a coexistence mechanism. Species-specific patterns of
<figure><img src="image_562.png" /></figure>

seed predation, however, provide an alternative diversity maintenance mechanism, yet studies of seed predation patterns are too limited to support this mechanism. Quantitative coexistence theory suggests observations, experiments and statistics that would provide strong tests of these hypotheses, and

quantify their relative and absolute contributions to species coexistence. The evidence from the existing literature on these hypotheses will be reviewed, including evidence from biological invasions. Suitable studies for strong tests of the various hypotheses will be proposed.

# S.244 METHODS IN INTEGRATIVE TAXONOMY: BRIDGING THE PHYLOGENY TO CLASSIFICATION GAP. SESSION 1

## S.244.1 New approaches for machine-learning-based integrative taxon-omics in plants

Karbstein, Kevin<sup>1,2*</sup>, Kösters, Lara<sup>1</sup>, Hodač, Ladislav<sup>1</sup>, Hofmann, Martin<sup>2</sup>, Mäder, Patrick<sup>2,3,4</sup>, Wäldchen, Jana<sup>1,3</sup>

1 Max Planck Institute for Biogeochemistry, Jena, Germany. 2 Technical University of Ilmenau, Institute for Computer and Systems Engineering, Ilmenau, Germany. 3 German Centre for Integrative Biodiversity Research, Leipzig, Germany. 4 Friedrich Schiller University, Institute of Ecology and Evolution, Jena, Germany. \*kkarb@bgc-jena.mpg.de.

Species are the central units for taxonomic research and measuring Earth's biodiversity. Recent findings in evolutionary genomics are raising awareness that what we call species can be ill-founded entities due to solely morphology-based or regional species descriptions. This particularly applies to plant groups characterized by intricate evolutionary processes such as hybridization, polyploidy, and/or apomixis. Here, challenges of integrative taxon-omics, that is genomics combined with morphological, ecological, and other datasets, become apparent: (i) different favored species concepts (e.g., genetic vs. morphological concepts), (ii) missing appropriate analytical tools for intricate evolutionary processes (which often hurt assumptions of popular MSC-based models), and (iii) highly subjective ranking and fusion of datasets for final taxonomic treatments (e.g., whether genetics or morphology is taxonomically most important). Now, integrative taxon-omics combined with machine learning (ML) under a unified species concept may enable systematic data integration and thus reduce subjectivity in species classification

and delimitation. Recent ML applications predominantly rely on deep learning, which represents automated feature extraction and learning based on artificial neural networks (ANNs). We introduce supervised (with labeled training datasets) and unsupervised (only using the inherent structure of testing datasets) ANN approaches that fuse genomic information with other sources (e.g., 'genomics', 'genomics+morphology', 'genomics+morphology+ecology', etc.) using integrative taxonomic datasets. Accuracy scores, confusion matrices, and bootstrapping techniques were applied to evaluate results. In addition, strategies to visualize highly important features within ANN classification or clustering processes ('XAI') and current ANN limitations will be discussed. Integrative taxon-omics based on ML may help classify or delimit species less subjectively as well as more reliably and rapidly than traditional methods do, and thus may help to revise and unravel plant diversity also on a global scale.

## S.244.2 Integrative taxonomic approach in unravelling the Systematics of Machilus glaucescens and M. macranthus (Lauraceae) from India

Nabasmita Malakar<sup>1,2</sup>, Gudasalamani Ravikanth<sup>1</sup>, K. Praveen Karanth<sup>3</sup>, Ganesan Rengaian<sup>1</sup>

1 Ashoka Trust for Research in Ecology and the Environment, Bangalore, India. 2 Manipal Academy of Higher Education, Manipal, Karnataka, India. 3 Centre for Ecological Sciences, Indian Institute of Science, Bangalore, India.
<figure><img src="image_563.png" /></figure>

The Asian genus *Machilus* (Lauraceae - wild relative of avocadoes) is widely distributed in South and Southeast Asia. The systematic profiling of the group has suffered from the lack of integrative taxonomic approach across the distributional range, including India. Historically, the taxonomic revision of *Machilus* in the Indo-Burmese region (Chakrabarty et al. 2022) did not improve the taxonomy and distribution. In this study, we used integrative taxonomic approach to delineate taxonomy, distribution, and phylogenetic relationship of *Machilus macranthus* Nees, (endemic to the Western Ghats-Sri Lanka hotspot), and *M. glaucescens* (Nees) Wight, (Indo-Burma region). We integrated morphological, molecular (nuclear and chloroplast), and distribution data to elucidate the systematic relationship. We collected individuals in flowering and fruiting from Assam, Meghalaya, and Mizoram of the Northeastern region of India and Western Ghats of south India. We sequenced the collections using two nuclear markers (*ITS* and *LEAFY*) and one chloroplast marker (*trnL-trnF*) for the phylogenetic analysis. We further explored 27 morphological characteristics for cluster analysis and extensively mapped the distribution of the species through primary and secondary sources. Cluster analysis using morphological characters, the distribution range as well as phylogenetic relationship confirms that *M. macranthus* and *M. glaucescens* are two distinct species and reflected two distinct distributional ranges. The phylogenetic result also supports the hypothesis that both are two distinct species. Our integrative taxonomic approach proved to be better to understand the systematics of species belongs to *Machilus* genus and could shed light on the origin and biogeography of the genus *Machilus* in the Asiatic region.

### S.244.3 A primer on integrative taxonomy

Robert Lücking¹, Karina Wilk²

1 Botanischer Garten Berlin, Freie Universität Berlin, Berlin, Germany. 2 W. Szafer Institute of Botany, Polish Academy of Sciences, Kraków, Poland.

The concept of "integrative taxonomy", until then restricted to define terminology the fields of psychology and business, was first introduced into biodiversity research in 2005, by the North American zoologist Benoît Dayrat, about twenty years after the onset of molecular phylogenetic research. Dayrat recognized a deep division between the field of molecular phylogenetics, which had developed new methods to test species boundaries, and the field of traditional taxonomy, which appeared to rely on typological approaches. He

defined "integrative taxonomy" as the "... science that aims to delimit the units of life's diversity from multiple and complementary perspectives (phylogeography, comparative morphology, population genetics, ecology, development, behaviour..." While Dayrat's argument focused on species delineation and the development of solid taxon concepts at the species level through multiple lines of evidence, integrative taxonomy has since then been expanded to encompass taxonomy at all hierarchical levels, with the aim to bridge the gap between molecular phylogenies and their translation into formal, stable classifications. Other terminology developed for this purpose includes "polyphasic taxonomy" and the "pluralistic species concept". Here, we redefine integrative taxonomy to encompass the following four components: (1) a molecular phylogenetic framework; (2) quantitative assessment and integration of non-molecular data (phenotype, ecology, behaviour, distribution, etc.) into this framework; (3) formal implementation of the results in a revised classification; and (4) providing revised identification tools reflecting the new classification. Using this strict definition, many works claiming to do "integrative taxonomy" actually fail to do so, either lacking a quantitative integration of non-molecular data or a revised formal classification. Methods for quantitative integration of non-molecular data are briefly outlined.

### S.244.4 Cryptic Beauty Revealed: Quantifying Phenotypic Variation in Two Vicariant Ophrys aveyronensis Populations via Image Processing

Anais Gibert¹, Florian Louty¹, Roselyne Buccal², Michel Baguette³,⁴, Bertrand Schatz⁵ and Joris AM. Bertrand¹

1 Laboratoire Génome et Développement des Plantes, Université de Perpignan Via Domitia-CNRS, Perpignan, France. 2 Centre de Formation et de Recherche sur les Environnements, Université de Perpignan Via Domitia-CNRS, Perpignan, France 3 Institut Systématique, Evolution, Biodiversité, Museum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France. 4 Station d'Écologie, Théorique et Experimentale, UMR 5321, CNRS, Université Toulouse III, Moulis, France. 5 CEFE, CNRS, Université Montpellier, EPHE, IRD, Montpellier, France.

Studying phenotypic differentiation is essential in understanding population divergence and the
traits involved in the speciation process. Detect-
ing slight phenotypic variations is difficult at first
glance, especially when species have a discon-
nected spatial distribution or conceal cryptic taxa.
To examine this, we implemented image-based
analyses in conjunction with a simple machine
learning algorithm to distinguish between two vi-
cariant population groups within an orchid spe-
cies complex acknowledged for its resistance to
differentiation using conventional morphological
criteria: *Ophrys aveyronensis*. Our all-encom-
passing approach involved three primary stag-
es: (i) Capturing and measuring 109 individuals in
their natural habitat, (ii) extracting morphomet-
ric, colour and colour pattern information from
field photographs and (iii) utilising random forest
algorithms for classification, the amalgamation
of field and image-derived data resulted in an
identification accuracy rate of 95%, highlighting
the efficacy of our multidimensional approach. It
is worth noting that the variables pinpointed by
the random forest algorithm for distinguishing
between the two population groups differed from
those typically proposed in current literature. This
captivating discovery emphasises the demand
for inventive techniques that go beyond tradi-
tional standards in phenotypic differentiation
studies. Our outcomes demonstrate the capacity
to augment taxon identification through combin-
ing field-captured images with machine learning
classification methods. Furthermore, they draw
attention to potential traits for future eco-evo-
lutionary investigations, offering valuable obser-
vations into the complex interplay of phenotypic
variations within intricate species. This study not
only aids in improving taxonomic methodologies
but also highlights the significance of advanced
analytical tools in enhancing our comprehen-
sion of species differentiation and evolutionary
mechanisms.

S.244.5 Exploring the
diversity of Wetmoreana
lichens (Teloschistaceae)
using an integrative
taxonomic approach

Karina Wilk¹, Robert Lücking²

1 W. Szafer Institute of Botany Polish Academy of Sciences, Krakow, Poland. 2 Botanischer Garten, Freie Universität Berlin, Berlin, Germany.

The genus *Wetmoreana* includes saxicolous,
crustose-lobate to squamulose species with
bright orange anthraquinones, often producing
vegetative propagules such as isidia, papillae,
schizidia or soredia. It is known throughout the
Americas, Africa and Asia. The origin of the ge-
nus is unknown, but the highest diversity occurs
in South America, perhaps indicating this conti-
nent as the centre of its diversification. The genus
was studied using quantitative integrative taxon-
omy methods to resolve its delimitation and ex-
plore its taxonomic diversity at the species level.
As a result, the number of taxa within *Wetmorea-
ana* increased from four to sixteen, including six
newly described species, as well as six species
newly transferred to this genus. Among the lat-
ter are some species for which DNA sequences
are as yet unavailable. Their classification with-
in *Wetmoreana* was tested using a quantitative
approach based on phenotypic traits combined
with the evaluation of phylogenetic signals by
means of phenotype-based phylogenetic bin-
ning. Clade distinctiveness of all recognised taxa
at the generic, specific and intra-specific levels
was assessed by a multi-response permutation
procedure (MRPP). The taxa of interest mainly
represent poorly studied South American spe-
cies and are characterized by a certain variabili-
ty in phenotypic traits. Such variable taxa pose a
challenge to taxonomists, and our results confirm
the usefulness of statistical methods in assessing
such difficult species complexes.

S.244.6 Anarchy to
Harmony: Redbud (Cercis
spp.) as a case for
integrative taxonomy

Mason C. McNair¹, Caitlyn Hughes², James Leebens-Mack²

1 Department of Plant & Environmental Science, Clemson University, South Carolina, USA. 2 Department of Plant Biology, University of Georgia, USA.

The genus *Cercis*, like many genera, is fraught
with taxonomic controversy. Circumscriptions of
species, subspecies, varieties, and forms of North
American taxa are hotly debated in taxonomic
and horticultural literature. Common garden as-
sessment of phenotypic variation and documen-
tation of the genetic basis of phenotypic variation
can inform taxonomic circumscription. We inves-
<figure><img src="image_564.png" /></figure>

tigated published delimitations for North Amer-
ican *Cercis* taxa through analysis of phenotypic
variation among specimens growing in a com-
mon garden (JC Raulston Arboretum, North Car-
olina State University). In addition, we leveraged an
available breeding population for genomic esti-
mation via GWAS and for phenotypic traits that
have been used to distinguish *Cercis canadensis*

var. *canadensis* and *Cercis canadensis* var. *tex-
ensis*. By combining phenotypic information with
an understanding of the genetic basis of key tax-
onomic traits, we illustrate how a pluralistic and
integrative approach to taxon delimitation can
yield rigorous and reproducible species and in-
fraspecific taxonomic concepts.

**S.245 FLORAS AND DIVERSITY OF EASTERN**
**ASIA. SESSION 1**

S.245.1 Moscow Digital
Herbarium and Atlas of the
Russian Flora initiative

Alexey P. Seregin¹, Sergey V. Dudov¹,
Natalia S. Gamova¹

1 Lomonosov Moscow State University, Moscow, Russia.

A web-resource, the Moscow Digital Herbarium
(https://plant.depo.msu.ru/), was launched by Lo-
monosov Moscow State University in October, 2016
for publication of specimens imaged and data-
based in the Moscow University Herbarium (MW).
From 2015 to 2018, a commercial partner scanned
93% of the regular herbarium collections at 300 dpi
and 100% of the types at 600 dpi. Since 2019, Moscow
Digital Herbarium became a consortium of Rus-
sian herbaria with nine active members (MW, MHA,
IRKU, KUZ, TUL, TULGU, KULPOL, TKM, MAG). As of August
2023, database contained 1,266,139 specimens with
1,244,376 images covering 36,171 species of vascular
plants and bryophytes. These data are available in
GBIF as nine independent datasets and updated in
a weekly synchronization mode. Gradually, we start-
ed to publish extended metadata on our portal, like
full transcriptions of labels and georeferences, i.e.,
the coordinates of collection sites for each speci-
men. Two thirds of records (890,356 specimens) are
currently georeferenced and 600,424 specimens
have complete label transcriptions. Atlas of the Rus-
sian Flora is a new initiative for producing grid maps
of native vascular plants of the country. This initia-
tive is integrated into the Moscow Digital Herbarium
and employs different data sources merged into a
single FLORUS dataset. Ca. 6.5M+ records (700K grid
records) were used to produce 9,885 grid maps

with 100×100 km squares. This dataset includes pre-
cleaned GBIF data (including data from the Moscow
Digital Herbarium), complete data from the Flora of
Russia project on iNaturalist, as well as previously
unpublished records. The taxonomy is given against
the Catalogue of Life associated with the accepted
names in the Moscow Digital Herbarium. Acknowl-
edgments: The work was supported by a grant from
the Russian Science Foundation (project No. 21-77-
20042, https://rscf.ru/en/project/21-77-20042/).

S.245.2 Invasive alien flora
of China: An update

Qiang Hao¹, Jin-Shuang Ma¹

1 China National Botanical Garden (North Garden),
Beijing, China.

China is the largest country in eastern Asia and
contains habitats that range from cold temperate
to tropical rainforest. The Chinese have a long histo-
ry of plant cultivation and domestication. Although
most cultivated plants in China are native species,
many are non-native plants introduced through-
out Chinese history for food, medicine, horticulture
or ornamental purposes. The Catalogue of Alien
Plants in China records a total of 14,710 alien plants.
Among these, some, such as corn and potato, are
used as food to meet the demands of China's large
population. Non-native plants that have established
populations and colonized local environments are
called naturalized plants. Previous studies indicate
that the number of naturalized plant species in Chi-
na ranges from 861 to 933. Of those, between 126 to
402 have been designated as Invasive Alien Plants.
In China, invasive plants have been detrimental to
the conservation of biodiversity and native ecosystems.
<figure><img src="image_565.png" /></figure>

tems, particularly since the 1990s. Thus, it is critical
to use multidisciplinary, nation-wide approaches to
investigate invasive plants in China. Here we present
an analysis of 403 invasive plant species based on
the Alien Invasive Flora of China and other recently
published works.

S.245.3 An overview of
current checklist of vascular
plants in Mongolia

Magsar Urgamal¹, Shukherdorj
Baasanmunkh², Batlai Oyuntsetseg³

1 Laboratory of Plant Systematics and Phylogenetics, Botanic Garden and Research Institute, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia. 2 Department of Biology and Chemistry, Changwon National University, Changwon, South Korea. 3 Department of Biology, School of Arts and Science, National University of Mongolia, Ulaanbaatar, Mongolia.

In this study, we critically revised and updated the
checklist of native vascular plants of Mongolia. The
checklist comprises 3,041 native vascular plant taxa
(2,835 species and 206 infraspecific species) from
653 genera and 111 families, including 7 lycophytes,
41 ferns, 21 gymnosperms, and 2,972 angiosperms.
In the angiosperms, we identified the 14 families with
the greatest species richness, ranging from 50 to 456
taxa. Species endemism is also noted here; 102 taxa
are endemic to Mongolia, and 275 taxa are suben-
demic that co-occur in adjacent countries. Since
2014, a total of 14 taxa have been described new to
science based on morphological evidences. More-
over, five genera and 74 taxa were newly added to
the flora of Mongolia. Based on our critical revisions,
names of three families, 21 genera, and 230 species
have been changed in comparison to the previous
checklist, "Conspectus of the vascular plants of Mon-
golia" (2014). We revised the checklist of Mongolian
vascular plants provided by Urgamal et al. (2014),
which included 3,127 taxa, belonging to 683 genera
and 112 families. There were 3,069 native taxa from
682 genera and 110 families listed by Urgamal et al
(2014) and the current checklist has been shortened
and comprises 3,041 native vascular plant taxa from
653 genera and 111 families. There are 10 families with
a high species richness (> 10 genera / > 94 species):
Asteraceae (85 genera/456 species), Fabaceae
(24/328), Poaceae (58/229), Rosaceae (28/168), Ra-
nunculaceae (20/156), Brassicaceae (51/138), Cyper-
aceae (10/131), Lamiaceae (22/103), Caryophyllaceae
(20/97), and Amaranthaceae (34/94). At the genus

level, 10 genera represent a high species richness (> 40 species): *Astragalus* L. (127 species), *Artemisia* L. (103), *Carex* L. (99) *Oxytropis* DC. (97), *Potentilla* L. (75), *Saussurea* DC. (55), *Taraxacum* F.H.Wigg. (53), *Allium* L. (50), *Salix* L. (42), *Ranunculus* L. (41).

S.245.4 Global National
Management List of Invasive
Alien Plants: Key Species
and Policy Analysis

Feifei Li¹, Jin-shuang Ma¹

1 China National Botanical Garden (North Garden),
Beijing, China.

Invasive alien plants (IAPs) pose a major threat to
biodiversity and ecosystems worldwide. The recent
adoption of the Kunming-Montreal Global Biodi-
versity Framework sets an ambitious "Target 6" for
tackling invasive alien species. Our study provides
a comprehensive analysis of the current national
management list of IAPs. It aims to answer the ques-
tions for achieving this target: Which species are
priority IAPs/potential IAPs/should be eradicated or
controlled in priority sites? How to manage IAPs to
achieve the target? 107 countries/union were ana-
lyzed, and only 26 of them have officially released
national management IAPs lists. 65% of them are le-
gal documents while 35% are only official lists. These
countries/union span six continents. France, South
Africa and Argentina have more than 300 IAPs, while
Slovakia only has seven IAPs. Based on all of the lists,
1316 taxa were compiled, belonging to 683 genera
and 149 families. The families with the most taxa are
Poaceae (159) and the genera with the most taxa
are *Prosopis* (29). 104 taxa distributed in at least
three continents and listed in four or more coun-
tries/union were considered as the priority IAPs in our
study. We also found species exchanged between
the Eastern and Western Hemispheres have been a
major pathway enabling plant invasions worldwide.
For potential IAPs, we suggested the long-distance
pathways between the Eastern and Western Hemi-
spheres should be a top focus for prevention and
pathways management. Aquatic IAPs are recog-
nized as top priorities for prevention and control in
island nations and other vulnerable sites. Addition-
ally, our study revealed that most countries/union
lack concrete control and management measures.
This indicates that significant improvements are still
needed to align IAPs lists and policies with the called
for Target 6.
<figure><img src="image_566.png" /></figure>

## S.245.5 Diversity, taxonomy and evolutionary history of the ferns Hymenophyllaceae in China: a phylogenetic and biogeographic approach

Yanan Zhao¹

1 Institute of Systematics, Evolution and Biodiversity, Muséum national d'Histoire naturelle, Sorbonne Université, CNRS, EPHE-PSL, UA, Paris, France.

Hymenophyllaceae, encompassing over 600 recognized species, are useful as indicators of the threatened humid forest environments at a pantropical scale. Emerging at least in the early Triassic and maybe in the Paleozoic, the family has ancient origins and displays a worldwide distribution resulting from significant diversifications and potential vicariance events since the Mesozoic. The taxonomic stabilization at family level is necessary and a prerequisite for biogeographic research, providing insights into its evolutionary history, including diversification patterns and processes. With nearly 1/3 of the world's species, Asia would likely be the origin area of certain lineages. Furthermore, China would host approximately 70 species of Hymenophyllaceae, representing over 10% of the total family diversity, making it a potential key area for biogeographic studies at an Asian and global scale. Therefore, an updated revision of Hymenophyllaceae diversity and taxonomy in China appeared essential and has yet to be conducted. For this purpose, a first step was to revise the list of names, descriptions and a representative sample of specimens in the collections, including types, with the aim to provide an updated list of valid Chinese taxa and their verified synonyms, and to generate an online identification key. In a second step, we acquired DNA sequences for many Chinese specimens, used *rbcL* to reconstruct phylogenies for Trichomanoideae (6 genera in China: *Abrodictyum*, *Callistopteris*, *Cephalomanes*, *Crepidomanes*, *Didymoglossum*, *Vandenboschia*), and *rbcL* combined with *rbcL-accD* and *rps4-trnS* for the genus *Hymenophyllum*. With these datasets and by conducting dating and biogeographical analyses, we tested species hypotheses, and the role of China in the assembly of the family biodiversity, especially in Asia, was explored and is discussed. Hymenophyllaceae are emblematic and indicators of fragile and threatened wet habitats. This taxonomy work is thus integral to a conservation and decision support perspective.

## S.245.6 Advancements in Chinese plant names index: a comprehensive overview

Cheng Du¹, Jun Liu², Shuai Liao³,⁴, Jinshuang Ma⁵

1 Eastern China Conservation Centre for Wild Endangered Plant Resources, Shanghai Chenshan Botanical Garden, Shanghai, China. 2 Zhejiang University Library, Hangzhou, China. 3 Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China. 4 South China National Botanical Garden, Guangzhou, China. 5 National Botanical Garden (North Garden), Beijing, China.

China's plant biodiversity, boasting 38,844 species, ranks among the highest globally. Since 2000, it consistently reports 220 new vascular plant taxa annually, with notable changes in names and national-level records. Despite most findings being published internationally, some, particularly from regional and university sources, lack representation in global databases. To address this, a systematic review of Chinese plant nomenclature literature since 2000 has been undertaken. This effort has resulted in annual plant species name indices and the Chinese Plant Names Index (https://cpni.ibiodiversity.net/) database, hosting 16,495 entries from 7,565 publications. This platform aims to fill the gap for species excluded from international databases, facilitating convenient access to plant name data for taxonomic revision and research citation. The comprehensive initiative extends beyond plant names, compiling data on 3,305 to avoid hip homonymity and enhance research accuracy. Additionally, information on 7,458 Chinese plant collection sites, with historical and contemporary spellings, aids precise referencing for researchers. The systematic organization of China's plant taxonomy documents not only advances botanical research but also contributes to the conservation and sustainable use of the country's abundant plant resources. In summary, the project addresses the underrepresentation of Chinese plant species in global databases by systematically organizing and disseminating information on plant taxonomy, aiming to enhance accuracy in botanical research, citation, and ultimately support the conservation and sustainable utilization of China's diverse plant resources.
# S.246 RANUNCULALES: FROM MORPHOLOGY TO PHYLOGENOMICS AND EVO-DEVO

## S.246.1 RanOmics: genomic tools for studying evolutionary innovations on the molecular scale in Ranunculales

Le-Han Nguyen¹, Doudou Kong¹, Oliver Rupp², Svent Griep², Alexander Goesmann², Annette Becker¹

1 Institute of Botany, Justus-Liebig-University, Giessen, Germany. 2 Institute of Bioinformatics and Systems Biology, Justus-Liebig-University, Giessen, Germany.

One of the central goals of evolutionary research is to understand how changes in gene regulatory networks lead to the origin of novel, complex traits, or, in short: How do evolutionary novelties arise? Ranunculales are early branching eudicots that comprise extremely morphologically diverse species and they are special because several morphological novelties evolved repeatedly, and novel floral traits emerged. I introduce the RanOmics project, aimed at uncovering gene regulators modules required for the emergence of novel, often convergently emerging traits. We have sequenced the genomes in reference quality of several Ranunculales and the transcriptomes of several species from homologous tissues and comparable developmental stages. I provide the state of the art of this project with the first comparative analyses of the genomes. The RanOmics project provides the genetic resources for the Ranunculales community and all researchers interested in studying comparative genomics, evolution of gene regulatory networks, and origin of novel traits.

## S.246.2 Petal evolution and morphogenesis in Ranunculaceae

Pauline Delpeuch¹,², Florian Jabbour², Catherine Damerval³, Jürg Schönenberger⁴, Susanne Pamperl⁴, Maxime Rome⁵, Katia Belcram⁶, Antoine Plumerault⁷, Sophie Nadot¹

1 Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique et Evolution, Gif-sur-Yvette, France. 2 Institut de Systématique, Evolution, Biodiversité, Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France. 3 Université Paris-Saclay, INRAE, CNRS, AgroParisTech, Génétique Quantitative et Evolution-Le Moulon, Gif-sur-Yvette, France. 4 Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria. 5 Jardin du Lautaret, CNRS, Université Grenoble Alpes, Grenoble, France. 6 INRAE, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, AgroParisTech, Versailles, France. 7 Previously, Massy, France.

Ranunculaceae comprise 2500 species that display a broad range of floral diversity, particularly at the level of the perianth. Petals, when present, are often referred to as 'elaborate' because they have a complex morphology. In addition, the petals usually produce and store nectar, which gives them a crucial functional role in the interaction with pollinators. Its morphological diversity and species richness make this family a particularly suitable model group for studying the evolution of complex morphologies. For this purpose, we scored and analysed traits that characterize in detail the complexity of mature petal morphology in 32 genera (out of 55), and used an already published robust and dated phylogeny of the family to conduct ancestral state reconstruction. Furthermore, we described petal development using high resolution X-Ray computed tomography in six species with contrasting petal forms. Our results suggest a flat and shortly clawed ancestral petal for the entire family, and for the ancestors of all tribes except Adonideae. Elaborations would have therefore evolved independently in different lineages, with some convergences in shape. To further explore the morphogenesis of elaborations, we focused on the spurred petals of Staphisagria picta. We described the cellular characteristics (volume, sphericity, orientation in space) of the developing spur using a newly designed automated method to analyse in a three-dimensional space images generated using confocal microscopy. Our results show that spur development is marked by an early phase of dominant cell proliferation, followed by a phase of dominant anisotropic (directional) cell expansion. The acquisition of the spur's curvature seems to be achieved by a complex interplay of anisotropic cell elongation and cell division, both mechanisms being unevenly distributed among the different parts of the spur.
<figure><img src="image_567.png" /></figure>

### S.246.3 Curiouser and curiouser: mechanisms underlying spur development and diversification in Aquilegia

Elena M. Kramer¹, Yang Gong¹, Ya Min², Evangeline Ballerini³, Scott A. Hodges⁴

1 Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA. 2 Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT USA. 3 Department of Biological Sciences, California State University, Sacramento, CA, USA. 4 Department of Ecology, Evolution and Marine Biology, University of CA, Santa Barbara, CA, USA.

The lower eudicot model system *Aquilegia* possesses several morphological features that can shed light on the evolution of novelty, particularly in the context of complex organ form. We have been studying several key aspects of the *Aquilegia* flower but will focus today on the three-dimensional petal nectar spur. We have found that *Aquilegia* petal spurs initiate due to a localized region of cell division. This lays the ground pattern of the spur, which is then realized through anisotropic cell elongation. Diversification of spur morphology has involved multiple factors, including heterochronic shifts that generate much longer, narrower cells; differences in cell numbers around the radial axis of the spur and along its length; and independent control of both cell division and elongation on different surfaces of the spur, which generates curvature. We are now combining transcriptomics, candidate gene approaches, and QTL mapping to explore the genetic architecture of spur development and understand its evolution.

### S.246.4 Dissecting the genetic and developmental basis of petal spurs in Aquilegia using QTL, hybridization and phylogenomics.

Scott A. Hodges¹

1 Department of Ecology, Evolution and Marine Biology, Univ. of California, Santa Barbara, USA.

The origin of nectar spurs is associated with the adaptive radiation of the columbine genus, *Aquilegia*. Dissecting the genetic and developmental mechanisms of nectar spur development specifically and petal morphology generally is thus important for our understanding of the origin of novel traits. Recently, a key gene in *Aquilegia* spur development, *POPOVICH*, was identified using hybridization between a natural spurless species, *A. ecalcarata*, and a spurred relative exemplifying the utility of natural variants. I outline our ongoing efforts to identify additional potential genes for spur and petal development using natural variation in the closest relatives of *Aquilegia*, *Semiaquilegia* and *Urophysa*. There have been recent discoveries of rare species of *Semiaquilegia* with novel petal shapes and we have been able to produce intergeneric hybrids between some of these species and *Aquilegia*, which offers a new research avenue. *Urophysa* consists of two species, *U. rockii*, which produces small petals with very short spurs and *U. henryi*, which in one accession produces small flat petals and in another produces small cupped-shaped petals but no spurs. Thus, QTL analysis from hybrids among these species will also likely aid in finding candidate genes involved in petal shape. Finally, we are developing genomic assemblies of both *Semiaquilegia* and *Urophysa* to facilitate the identification of genomic features unique to *Aquilegia* and thus potentially being involved its adaptive radiation.

### S.246.5 Developmental genetics of floral traits associated with wind pollination in Thalictrum

Verónica S. Di Stilio¹, Anthony G. García¹

1 Department of Biology, University of Washington, Seattle, USA.

Wind pollination has evolved repeatedly in flowering plants, yet the developmental genetics of floral traits associated with this pollination mode remains elusive. *Thalictrum* (Ranunculaceae) have transitioned repeatedly between insect and wind pollination and exhibit intermediate floral morphs with mixed pollination, providing an ideal system to test the correlated evolution of floral morphology, developmental genetics and pollination mode. Prior data broadly sup-
<figure><img src="image_568.png" /></figure>

ports the existence of detectable flower morphs from convergent evolution to wind pollination in *Thalictrum*, consisting of small, inconspicuous, and mostly dioecious flowers with extended stigmatic surfaces on long styles or dangling stamens. *MIXTA* family transcription factors are known to modulate the differentiation of cellular outgrowths (conical cells and trichomes) on the epidermis of land plants and were tested here as potential candidates for the longer stigmatic papillae and extended stigmas found in wind-pollinated species. A single copy ortholog from diploid *T. thalictroides*, *paleoMIXTA* (*TthPMX*), was functionally characterized via targeted gene silencing and overexpression, followed by comparative transcriptomics to investigate the gene regulatory network. The reduction in stigmatic papillae length under targeted gene silencing and their extension under over-expression suggest that *TthPMX* has a novel role in promoting stigmatic papillae cell elongation. Elevated expression of specific *PMX* paralogs in carpels of polyploid taxa further suggests that duplications in *PMX* may have facilitated the evolution of the long stigmatic papillae found in plumose stigmas of wind-pollinated species.

## S.246.6 Ranunculaceae: from Morphology to Phylogenomics and Evolutionary Developmental Biology

Xuehao Fu¹,², Boka Li¹,²,³, Tianyu Lei¹,²,³, Hongyan Shan¹,², Hongzhi Kong¹,²,³

1 State Key Laboratory of Plant Diversity and Specialty Crops, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing, China. 2 China National Botanical Garden, Beijing, China. 3 University of Chinese Academy of Sciences, Beijing, China.

Ranunculaceae exhibits a remarkable diversity in genome size, floral morphology, and secondary metabolites. How these characters evolved, and to what extent the changes of genome size have contributed to the evolution of other characters, however, remain largely unclear. Here, by sequencing the genome of *Nigella damascena* (genome size about 10 Gb) and the transcriptomes of the other 51 species representing 37 genera of the 14 tribes, we: 1) constructed a robust

and well-represented phylogenetic tree with time calibration of the Ranunculaceae, and detected two gene flows that have resulted in nuclear-cytoplasmic incompatibility; 2) explored the processes and general patterns of the evolution of genome size and other important characters; 3) revealed the mechanisms underlying the diversification of flowers in basic structure, petal shape and several phytochemical traits, and 4) discussed the roles of the changes of genome size in plant evolution.
# S.247 FLORAL NECTAR: POLLINATION SYNDROMES, PRODUCTION ATTRIBUTES, REGULATION EVOLUTION. SESSION 2

## S.247.1 Nectar secretion mechanism in a monocot Roscoea (Zingiberaceae)

Wen-Jing Wang¹, Hong-Fan Chen¹,², Yue Gao¹, Hong Liao¹, Jian-Li Zhao¹

1 Ministry of Education Key Laboratory for Trans-boundary Ecosecurity of Southwest China, Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan, China. 2 Institute of International Rivers and Eco-security, Yunnan University, Kunming, Yunnan, China.

Nectar serves as a reward offered by flowers to pollinators, facilitating the success of sexual reproduction. Consequently, nectar holds indispensable biological significance in plant reproduction and evolution. Despite the characterization of nectar function and composition, the mechanism of nectar secretion has remained unclear. To elucidate the probable mechanisms governing nectar secretion, we selected two *Roscoea* species as model: the outcrossing species *R. cauteleoides*, secreting nectar from its nectaries, and the autonomous selfing species *R. schneideriana*, no nectar. We first conducted a comparative study for micro-structure, nectary size and nectar volume were recorded in the field. Nectary location, external form and internal structure were observed by paraffin section staining method. Subsequently, we performed an intricate assembly and annotation of the *R. cauteleoides* genome, employing multi-omics techniques, facilitating an analysis of the molecular mechanisms in the nectaries and doing identification of target genes crucial for nectar secretion. Ultimately, we delved into the gene structure, function and evolution of these essential genes. Here, we found that the nectaries of *R. schneideriana* possess significantly reduced volume and deteriorated internal structures, compared to *R. cauteleoides*. Multi-omics correlation analysis identified one gene that is specifically highly expressed in the nectaries of the *R. cauteleoides*, which is critical for nectar secretion in *Roscoea*. These results provide

an important basis for revealing the differences of floral characteristics, pollination mechanism and breeding system, as well as the mechanism of nectar secretion between outcrossing and selfing species in *Roscoea*. Characterization of this target gene regulating nectary production has provided new insights into understanding of the mechanism and evolution of nectar secretion in plants.

## S.247.2 Predicting pollination syndromes along an altitudinal gradient of the tropical Andes of Bolivia

Valeska De Cárdenas¹, Øystein H. Opedal², Sissi Lozada-Gobilard¹,²

1 Instituto de Ecología, Universidad Mayor de San Andrés, La Paz, Bolivia. 2 Biodiversity Unit, Department of Biology Lund University, Sweden.

Pollination syndromes refer to a set of flower characteristics, including flower structure, color, fragrance, and rewards, which have developed through interactions with a particular category of animal pollinators. The predictive power of pollination syndromes regarding actual plant-animal interactions has been constantly debated. Here we tested this prediction power in 30 plant species occurring along an altitudinal gradient (1000-4500m) in the tropical Andes of Bolivia. We measured flower traits, flower morphometry (size), signal (color, shape) and reward traits (nectar). In addition, we observed the pollinators (flower visitors that touched reproductive parts) corresponding to different pollinator guilds: bees, flies, wasps, beetles, butterflies and birds. Using the flower traits, we classified the plant species into a particular pollination syndrome. Later based on the most legitimate and abundant pollinators, we confirmed or rejected the predicted syndrome. Along the altitudinal gradient we expect to find different conditions related to both specialist and generalist strategies of pollination. If so, then we expect an accurate predictive power of the pollination syndromes in the specialist systems only.
<figure><img src="image_569.png" /></figure>

**S.247.3 The challenge of nectar production in Mucuna (Fabaceae): from anatomical to ecological traits**

Kayna Agostini¹, Leonardo Galetto², Marlies Sazima³

1 Depto of Natural Science, Mathematics and Education, Federal University of São Carlos, Araras, Brazil. 2 Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, Córdoba, Argentina. 3 Depto of Botany, State University of Campinas, Campinas, Brazil.

The genus *Mucuna* (Fabaceae) shows explosive flower opening and an impressive radiation involving different pollinators. The aim of this study was to verify how anatomical and ecological traits affect the dynamics of nectar production in the genus *Mucuna* which have a diversity of vertebrate pollinators. *Mucuna japira* (pollinated by birds) inflorescence bears 12-21 yellow flowers, which are in anthesis for seven days, whereas *M. urens* (pollinated by bats) inflorescence bears 36-54 greenish flowers, but only 1-3 flowers are in anthesis simultaneously, that last one night. Related to floral morphology, the reproductive organs are enclosed in the keel, being released after explosive flower opening. At the tip of the keel, the petals are stiff and united, which probably act as support to trigger flower explosion. In the non-ligated part of the inner epidermis occur entwined secretory papillae, which keep the petals firmly united. Both species had constant nectar sugar concentration (ca. 10% for *M. japira* and ca. 16% for *M. urens*) and secreted high volumes of nectar (ca. 340µl per flower for *M. japira* and 310µl per flower for *M. urens*), during five days for *M. japira* and six hours for *M. urens*, but nectar production stops immediately when flower opening mechanism is triggered. Nectar resorption occurred in both species since there is no longer any chance of flower being pollinated. Both species of *Mucuna* are dependent on their pollinators to produce fruits and seeds, but they have different strategies to promote the necessary interaction with birds or bats, especially related to nectar and flower traits. Also, anatomical traits can mediate pollinators visitation as secondary wall thickenings of the inner mesophyll exist only in *M. japira* flowers, which are more difficult to open than those of *M. urens*.

**S.247.4 Challenges and rewards of measuring selection on nectar**

Amy L. Parachnowitsch¹

1 Biology Department, University of New Brunswick, Fredericton, New Brunswick, Canada.

The importance of nectar in plant-pollinator interactions and the diversity of animal pollinated flowers has long been appreciated. However, nectar traits have generally been neglected in estimates of natural selection in populations. While researchers appreciate that nectar may be a target of selectin in populations, it can be a challenging trait to quantify in the numbers necessary for phenotypic selection studies. Here I outline some of the challenges and opportunities for studying selection on nectar. I also outline lessons we've been learning as my lab attempts to fill this important gap in our understanding of the evolution of floral traits. I'll show that nectar can be but isn't always a target of selection. Abiotic conditions can also change selection patterns on nectar. Quantifying selection on nectar traits may be particularly important to understand the impacts of our changing climate on floral evolution. Nectar can be a plastic trait influenced by current conditions, many which are changing, such as temperatures and water availability. Therefore, understanding the relationship between phenotypic plasticity and natural selection will be particularly important for furthering our understanding of the evolution of nectar.

**S.247.5 Identifying and measuring the role of natural selection in the evolution of floral nectar attributes: Avoiding the pitfalls**

Graham Pyke¹, Zong-Xin Ren², Nickolas Waser³

1 Macquarie University, Australia. 2 Kunming Institute of Botany, China. 3 University of California, Riverside, USA.

Determining how floral nectar attributes have evolved and continue to evolve is important and necessary for understanding, managing, conserving and manipulating plant biology. However, there are several pitfalls that can and do arise along this path. One pitfall is the
<figure><img src="image_570.png" /></figure>

assumption, often implicit, that plants evolve nectar attributes to benefit their animal pollinators, rather than themselves. Instead, floral nectar should be viewed as an evolutionarily stable strategy with fitness outcomes clearly identified for both plant nectar production and pollinator behaviour. To suggest that pollinators preferentially visit or revisit individual plants on the basis of their nectar attributes is similarly problematic because pollinators are generally unable to assess nectar attributes of a flower (volume, concentration, composition) without probing it and removing its nectar and unlikely to remember and preferentially revisit or avoid particular plants based on encountered nectar. Another pitfall is to argue, also often implicitly, that a plant population or species has certain nectar attributes because these attributes benefit the population or species rather than an individual plant. There are also problems with at-

tempts to measure what has been termed 'phenotypic selection' by observing correlations across individual plants between some measure of plant reproductive fitness (e.g., seed set) and various phenotypic traits, possibly including nectar attributes. In addition, measurements of 'phenotypic selection' sometimes omit consideration of male function reproduction which should be half the story. A final pitfall may arise when attempts are made to determine the nature and extent of natural selection in relation to nectar attributes through experimental manipulation because such experiments may not leave everything else unchanged. Determining how floral nectar attributes evolve will therefore require a carefully developed approach with much care given to avoiding the pitfalls described above. However, this may not be easy, especially given how easy it is for these pitfalls to arise.

## S.248 EVO-DEVO

### S.248.1 Perianth evolution in Ranunculales

Marcel Tunggawihardja¹, Julien B. Bachelier¹

1 Institute of Biology/Dahlem Centre of Plant Sciences, Freie Universität Berlin, Berlin, Germany.

As sisters to all other eudicots, members of the Ranunculales are pivotal to understanding the evolution of their perianth, and the homology of petals that can be of bracteal or staminal origin. However, recent ancestral character reconstructions suggest that the most recent common ancestor (MRCA) of Ranunculales and several families, including Berberidaceae, had not two but three series or whorls of perianth, and that the innermost was petaloid. To assess perianth organ evolution and homology between extant lineages and the MRCA of Ranunculales, we thus re-evaluated floral development in two genera of Berberidaceae with several whorls of perianth becoming increasingly petaloid toward the center of the flower. However, only the two innermost persist at anthesis in *Nandina* and four in *Vancouveria*. Using scanning electron microscopy, we confirmed that in both genera, the outermost whorls of sepals are all caducous. In addition, in *Nandina*, the two whorls of petals are not delayed in development and interpreted as the two innermost whorls of increasingly petaloid sepals, similar to those persisting in *Vancouveria*. Primordia at the base of some stamens of *Nandina* that we interpreted as be-

ing homologous to those regularly found in two whorls around the stamens in *Vancouveria* were also documented but they vanish during development whereas in *Vancouveria*, while they are typically delayed in development and form modified and nectariferous petals. Our study suggest that like in *Vancouveria*, the MRCA of Berberidaceae and Ranunculales as a whole likely had a perianth differentiated into outermost and innermost more or less petaloid sepals, and more or less modified and nectariferous petals. As such, their flowers thus had petals of both bracteal and staminal origins at anthesis, supporting the hypothesis of a fad-ing-border ABC model determining floral organ iden-tity and petaloidy in the basalmost eudicot lineage.

### S.248.2 New floral organs in Amaranthaceae: ontogeny and gene function

Ivonne Sánchez-del Pino¹, Alexander Vrijdaghs², Stefan de Folter³, Elsa Góngora¹, Valentín Luna García³

1 Centro de Investigación Científica de Yucatán A.C. Mérida, Mexico. 2 Ecology, Evolution and Biodiversity Conservation, KU, Leuven, Belgium. 3 Laboratorio de Genómica Funcional del Desarrollo de Plantas, Irapuato, Mexico.

Most eudicot angiosperms have flowers with four types of floral organs arranged in concen-
<figure><img src="image_571.png" /></figure>

tric whorls - sepals, petals, stamens, and carpels
- However, throughout the process of evolution, flower morphology has evolved, resulting in a variety of modifications such as the origin of new or the loss of existing floral parts, changes in the function of floral organs, and others. In Amaranthaceae, androecial tubes occur with appendages known as 'pseudostaminodes', alternating with the stamens. The characterization of the pseudostaminodes has been controversial with different definitions found in literature. However, a recent floral ontogenetic study based on scanning electron and light microscopy suggested that pseudostaminodes are a new category of floral organs called 'androecial appendages'. Two types of appendages were identified: appendages on the androecial tube and appendages on the filaments. To test this hypothesis and further clarify the nature of the androecial appendages, an RNA-seq study was conducted in order to obtain transcriptome sequences. Bioinformatic analyses were then performed to determine differentially expressed in these new floral organs, and their possible functions.

to attract different species, the genetic flow be-
tween them is interrupted, promoting plant differ-
entiation and speciation. However, until now we
lacked an understanding of the mechanisms be-
hind the development of the floral traits employed
in the mimicry. In this study, we investigate the
*Ophrys sphegodes* labellum, the highly special-
ized petal responsible for pollinator attraction, in
order to uncover the genetic basis of these floral
traits. We used a combination of microscopy, mi-
cro-computed tomography, and photography to
describe the morphology of the labellum during
the development. We delineated, for the first time,
seven distinct developmental stages, which will
be pivotal for subsequent studies. We also found
three main cell types that are localized in three
different areas of the labellum. With this knowl-
edge in hand, we created the first expression atlas
of labellum stages and tissues by RNA-Seq, so as
to be able to uncover the genes involved in polli-
nator-relevant traits of the labellum. These results
will facilitate future detailed evo-devo studies be-
tween *O. sphegodes* and other *Ophrys* species
with different pollinators.

S.248.3 Developmental
analysis of Ophrys
sphegodes labellum helps
to unravel the secrets of
sexual mimicry

Mattia Alessandrini<fnref n="1" />, Yannick M. Städler<fnref n="2" />,
Susanne Pamperl<fnref n="2" />, Salvatore Cozzolino³,
Jürg Schönenberger<fnref n="2" />, Philipp M. Schlüter<fnref n="1" />

The orchids of the genus *Ophrys* represent an ex-
cellent system to study pollinator-driven specia-
tion. These orchids have a particular pollination
strategy that involves the attraction of the males
of one specific species of insect, mimicking the
pheromone and the appearance of the conspe-
cific females. After landing on the flower, the de-
ceived male starts to perform a “pseudocopula-
tion”, which leads to removal of pollinia. Different
species of *Ophrys* typically attract different spe-
cies of insects due to the perfection of the decoy.
Thus, if two orchids vary enough in their floral traits

S.248.4 Knockdown of
floral symmetry in Fedia
graciliflora

Theresa A. Mustacchio<fnref n="1" />, Amila Radoncic<fnref n="1" />,
Yoland Savriama<fnref n="2" />, Jingjing Tong³,
Dianella G. Howarth<fnref n="1" />

1 Department of Biological Sciences, St. John's Uni-
versity, New York, USA. 2 Department Evolutionary
Genetics, Max-Planck Institute for Evolutionary Bi-
ology, Plön, Germany. 3 Department of Plant and
Soil Sciences, University of Delaware, Delaware, USA

Shifts between radial symmetry (actinomorphy) and bilateral symmetry (zygomorphy) in flowers have occurred multiple times independently within angiosperms. These morphological shifts are commonly associated with increased pollinator specialization and speciation rates. The CYCLOIDEA (CYC)-like genes have been shown to shift their expression dorsally independently in nearly all shifts to bilaterally symmetrical flowers examined. Three core eudicot clades of CYC-like genes have been identified: CYC1, CYC2 and CYC3, with only CYC2-like genes being shown to have a role in floral symmetry. We use the non-model plant, Fedia graciliflora (Caprifoliaceae-

<footnote n="1">1 University of Hohenheim, Dept. of Plant evolution-
ary Biology, Institute of Biology, Stuttgart, Germany.</footnote>

<footnote n="2">2 University of Vienna, Dept. Botany & Biodiversity Research, Vienna, Austria. 3 University of Napoli Federico II, Department of Biology, Naples, Italy.</footnote>
<figure><img src="image_572.png" /></figure>

ae) to examine the effect of CYC2 as well as CYC3 paralogs on floral shape and symmetry. F. gracili-flora have strongly bilaterally symmetrical flow-ers with morphologically distinct dorsal (upper), lateral, and ventral (lower) petals and only two functional stamens. Fedia is nested within the Va-lerianella, a group with pseudo-radially symmet-ric flowers with three functional stamens, provid-ing a model for studying the evolution of strong bilateral symmetry and teasing apart the effects from each paralog. Here we used Virus-Induced Gene Silencing (VIGS) to knockdown each of the paralogs separately: FgCYC2A, FgCYC2B, FgCY-C3A, and FgCYC3B. The down-regulated plants were assayed using geometric morphometrics combined with tools of multivariate statistical shape analysis to quantify shape changes, using a combination of landmarks and semilandmarks to precisely capture in high detail the corolla out-line. Using canonical variate analysis (CVA), we are able to statistically model the morpholog-ical effect of lower expression of each paralog. These analyses indicate that each paralog plays a slightly different role in patterning floral sym-metry, both in location and size of petal lobes. Additionally, here we show evidence for the first time that CYC3, despite having lower expression in general, also patterns corolla shape.

**S.248.5 Genetic basis**
**underlying heteranthery in**
**Melastomataceae.**

Suvrat Kotagal¹, Christian Siadjeu¹,
Gudrun Kadereit¹,²

1 Fakultät für Biologie, Systematik, Biodiversität & Evolution der Pflanzen, Ludwig-Maximilians-Universität München, Germany. 2 SNSB: Botanische Statatssammlung München und Botanischer Garten München-Nymphenburg, Germany.

Melastomes are well known for their striking diver-
sity in stamen morphologies. The variously mod-
ified connective appendages and heteranthery
(stamen dimorphism) occurring within this fam-
ily of ca. 5800 species, has fascinated botanists
for more than two centuries. A variety of functions
associated with pollination have been discovered
for these staminal traits over the years. Although
most species are buzz pollinated, repeated evo-
lutionary shifts in staminal traits have often been
linked to pollinator shifts and suspected of causing
diversification in the family. The evolutionary labil-

ity of the connective morphology and heteranth-
ery within several clades lead us to hypothesize
that these traits might be controlled by relative-
ly simple genetic mechanisms. We aimed to test
this hypothesis by using a comparative transcrip-
tomics approach and selected two closely relat-
ed *Arthrostemma* species with different degrees
of heteranthery for our studies. Suitable develop-
mental stages for transcriptomic comparisons
were identified and RNA was extracted by dissect-
ing and separating the two stamen whorls. Differ-
ential expression analyses were done to compare
the gene expression profiles of the tissues from
the two whorls of stamen within and between
species at different developmental stages. Further
analyses of the differentially expressed genes to
identify candidate genes/groups involved in pe-
doconnective development and heteranthery are
underway. We hope to gain a better understand-
ing of the genetic basis behind this phenomenon
of heteranthery and associated staminal traits to
use as a substrate for future evolutionary stud-
ies in melastomes and other angiosperm families
showing heteranthery.

S.248.6 Using Lonicera
(Caprifoliaceae) as an evo-
devo model clade to study
floral and extrafloral fusion
and shape.

Dianella Howarth¹, Mansa Srivastav¹,²,
Michael Donoghue², Wendy Clement³

1 Department of Biological Sciences, St. John's Uni-
versity, New York, USA. 2 Department of Ecology and
Evolutionary Biology, Yale University, Connecticut,
USA. 3 Department of Biology, The College of New
Jersey, New Jersey, USA.

Diversification in plant form commonly arises from
changes in regulation of rates of tissue growth
and location of tissue boundaries. *Lonicera*, with
roughly 140 species, displays considerable varia-
tion and multiple independent transitions in floral
symmetry; length of floral whorls; and fusion of
petals, ovaries, extrafloral bracteoles, and leaves.
We have used target enrichment to sequence
twenty candidate genes and a microRNA (across
most of the species) that are known to underlie
these traits in core eudicots and/or angiosperms.
In addition to genic coding sequence, we also
targeted potential upstream and downstream
<figure><img src="image_573.png" /></figure>

regulatory regions to examine changes in tran-
scription factor binding sites across the group
that correlate with morphological shifts. Our key
initial focus examined the role of CUC (CUPSHAPED
COTYLEDON) in frequent shifts in fusion of leaves,
bracteoles, and ovaries across Lonicera, with in-
dependent shifts recreating the same structures
repeatedly. CUC is a NAC1a transcription factor
that has been shown to affect organ boundaries
in leaves and floral organs. We previously used
genomic skimming and transcriptomic datasets
to infer the phylogenetic history of CUC across
Lonicera, and our findings suggest that there has
been a duplication of CUC2 and a genomic loss of
CUC3. This is the first known case of loss of CUC3 in
any angiosperm group, and it is correlated with a
marked increase in transitions in extrafloral fusion
across the Caprifoliaceae. We further show that
both CUC2 paralogs in Lonicera japonica and L.
sempervirens are more highly expressed in corolla
lobes than in the corolla tube, suggesting a func-
tion of CUC2 in separating tissues in Lonicera flow-
ers. Using our target enrichment dataset, we dis-
cuss changes in the CUC2 binding elements that
correlate with morphological shifts. We further use
this dataset to examine the larger gene regulatory
network that includes CUC.

S.248.7 Documenting
developmental transitions
and studying targeted
gene expression in the
gametophyte of ferns:
*Adiantum raddianum* and
*Anemia villosa*

Luis Miguel Prieto¹, Aura Urrea Trujillo¹,
Carolina Rodríguez-Pelayo², Natalia
Pabón Mora¹

1 Universidad de Antioquia, Instituto de Biología, Medellín, Colombia. 2 Instituto de Biología Celular y Molecular de Plantas, Universidad Politécnica de Valencia, Valencia, Spain.

Ferns constitute the second most diverse lineage
of vascular plants on Earth, surpassed only by an-
giosperms. In most recent phylogenies, ferns ap-
pear monophyletic. In both ferns and lycophytes,
gametophytes and sporophytes can grow in-
dependently as multicellular haploid and dip-

loid bodies, respectively. Gametes are generated
through cellular differentiation in the haploid ga-
metophyte, which by itself a product of spore ger-
mination. After fertilization, the zygote develops into
a new sporophyte. In comparison to angiosperms,
few developmental studies have focused on ferns,
and the studies made have emphasized morpho-
logical diversity and gene expression data in the
sporophytic phase. For instance, several studies
have addressed the expression of identity and
leaf development genes, as well as reproductive
transition genes in fronds and during sporangia
formation. Similar analyses are lacking in the hap-
loid phase: the gametophyte. This study standard-
ized spore germination and gametophyte growth
in *Adiantum raddianum* and *Anemia villosa*. Mor-
phological changes and developmental timing
were documented for all haploid stages, from
spore germination to zygote formation. Success-
ful optimization of RNA extractions from tiny indi-
viduals allowed expression analyses for *LEAFY* (*LFY*)
and *Phosphatidylethanolamine Binding Protein*
(*PEBP*) genes. These gene lineages control the re-
productive transition in angiosperms, and are hy-
pothesized to play similar roles in ferns, due to their
wide expression in fern sporophytes, especially in
sporangia throughout their maturation. Our data
shows active expression of *LFY* and *PEBP* homologs
in fern gametophytes. We discuss the specific ex-
pression patterns and their putative functions in
spore germination, gametophyte growth, or the
formation of antheridia and archegonia and ga-
metogenesis in early diverging vascular plants.
<figure><img src="image_574.png" /></figure>

**S.249.1 Phylogenomics of angiosperms based on mitochondrial genes: new insights into deep node relationships**

Dongliang Lin<sup>1,2,3</sup>, Bingyi Shao<sup>1</sup>, Zhiyuan Gao<sup>1</sup>, Jianwu Li<sup>4</sup>, Shanghai Li<sup>1</sup>, Tingyu Li<sup>2,5</sup>, Weichang Huang<sup>6</sup>, Xin Zhong<sup>6</sup>, Chao Xu<sup>1,3</sup>, Mark W. Chase<sup>7,8</sup>, Xiaohua Jin<sup>1,3</sup>

1 State Key Laboratory of Plant Diversity and Prominent Crops, Institute of Botany, Chinese Academy of Sciences, Beijing, China. 2 University of Chinese Academy of Sciences, Beijing, China. 3 China National Botanical Garden, Beijing, China. 4 Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yunnan, China. 5 Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China. 6 Shanghai Chenshan Botanical Garden, Songjiang, Shanghai, China. 7 Royal Botanic Gardens, Kew, Richmond, Surrey, UK. 8 School of Plant Biology, University of Western Australia, Crawley, Perth, Australia.

Angiosperms are the largest plant group and play an essential role in the biosphere. Phylogenetic relationships of many families and orders remain controversial despite 30 years of study, and, in an attempt to address these, we performed the most extensive sampling of mitochondrial genes to date. We reconstruct a seed plant phylogenetic framework based on 4l mitochondrial protein-coding sequences (MTCDSs). The results for major clades of angiosperms have moderate to strong support (>70% bootstrap) for more than 80% of the nodes and strong support for monophyly of most orders. Eight major nodes were supported in this study, including three paraphyletic ANA grade (Amborellales, Nymphaeales, and Austrobaileyales) and five major core angiosperm branches. Chloranthales and Ceratophyllales are placed sister to the eudicots, whereas the monocots are placed sister to the magnoliids. A new order, Huales, was proposed to establish to accommodate phylogenetic isolated Huaceae. Our results indicated that mitochondrial genomic data were effective at resolving deep node relationships of angiosperm phylogeny.

**S.249.2 Glue them all: innovative recycling genomic sequencing resources using universal Angiosperms353 probe sets**

Miao Sun<sup>1</sup>, Xueqin Wang<sup>1</sup>, Tao Xiong<sup>1</sup>, Yiying Wang<sup>1</sup>, Xinru Zhang<sup>1</sup>

1 National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, China.

With the continuous advancement of sequencing strategies, high-throughput sequencing (HTS) technologies have developed as one of the most important tools in plant phylogenomics. Target capture sequencing, particularly hybridization target enrichment sequencing (Hyb-seq), is a crucial HTS sequencing strategy known for its flexible probe design, which has been becoming a standard method of phylogenomics. The widely used universal Angiosperms353 probe sets (Angiosperms353) play a pivotal role in Hyb-seq and have increased applications in recent years. We have comprehensively assessed the potential application for Angiosperms353 by combing a large amount of literature and empirical datasets. We found that RNA-seq strategy captures the highest number of Angiosperms353 genes, and then followed by whole genome sequencing and genome skimming strategies; increasing sequencing depth leads to higher yields of captured genes; and no obvious bias was observed for the yields of Angiosperms353 across all angiosperm groups we tested. Hence, based on the knowledge acquired above, we used Angiosperms353 extracted from genome resequencing data, and attempted to build a phylogeny for all the seed plants, as well as phylogenomics of Elaeagnaceae and Rosaceae. In the era of genomics with large volumes of HTS data, our works demonstrate the practical application of Angiosperms353 by innovatively recycling vast genomic sequencing resources, maximizing genomic data sharing and utilization.
<figure><img src="image_575.png" /></figure>

**S.249.3 Phylogenomic insights into the evolutionary history of evergreen broadleaved forests in East Asia under Cenozoic climate change**

Sheng-Yuan Qin¹,², Zheng-Yu Zuo¹, Cen Guo¹, Xin-Yu Du¹, Shui-Yin Liu¹,², Xiang-Qin Yu³, Xiao-Guo Xiang⁴, Jun Rong⁴, Bing Liu⁵,⁶, Zhi-Fang Liu⁷, Peng-Fei Ma¹, De-Zhu Li¹,²,³

¹ Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China. ² University of Chinese Academy of Sciences, Beijing, China. ³ CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China. ⁴ Jiangxi Province Key Laboratory of Watershed Ecosystem Change and Biodiversity, Centre for Watershed Ecology, Institute of Life Science and School of Life Sciences, Nanchang University, Nanchang, China. ⁵ State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China. ⁶ Sino-African Joint Research Center, Chinese Academy of Sciences, Wuhan, China. ⁷ Key Laboratory of Chemical Biology of Ministry of Education, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China.

The evergreen versus deciduous leaf habit is an important functional trait for adaptation of forest trees and has been hypothesized to be related to the evolutionary processes of the component species under paleoclimatic change, and potentially reflected in the dynamic history of evergreen broadleaved forests (EBLFs) in East Asia. However, knowledge about the shift of evergreen versus deciduous leaf with the impact of paleoclimatic change using genomic data remains rare. Here, we focus on the Litsea complex (Lauraceae), a key lineage with dominant species of EBLFs, to gain insights into how evergreen versus deciduous trait shifted, providing insights into the origin and historical dynamics of EBLFs in East Asia under Cenozoic climate change. We reconstructed a robust phylogeny of the Litsea complex using genome-wide single-nucleotide variants (SNVs) with eight clades resolved. Fossil-calibrated analyses, diversification rate shifts, ancestral habit, ecological niche modelling and climate niche reconstruction were employed to estimate its origin and diversification pattern.

Taking into account studies on other plant lineages dominating EBLFs of East Asia, it was revealed that the prototype of EBLFs in East Asia probably emerged in the Early Eocene (55-50 Mya), facilitated by the greenhouse warming. As a response to the cooling and drying climate in the Middle to Late Eocene (48-38 Mya), deciduous habits were evolved in the dominant lineages of the EBLFs in East Asia. Up to the Early Miocene (23 Mya), the prevailing of East Asian monsoon increased the extreme seasonal precipitation and accelerated the emergence of evergreen habits of the dominant lineages, and ultimately shaped the vegetation resembling that of today.

**S.249.4 New genetic markers for phylogenomic studies in Amaranthaceae sensu stricto**

Tina Kiedaisch¹, Diego Morales-Briones¹, Gudrun Kadereit¹, Anže Žerdoner Čalasan¹

¹ Ludwig Maximilian University of Munich, Munich, Germany.

Amaranthaceae sensu stricto form a monophyletic group within the Amaranthaceae (including Chenopodiaceae) comprising 80 genera and 900 species. Amaranthaceae s.s. are found predominantly in tropical and subtropical regions worldwide. In Australia 10 genera with together ca. 190 species occur, spread across the entire continent including also arid biomes. Current phylogenies are insufficient to understand the complex evolutionary history of the lineage which is challenging due to three whole genome duplication events, rapidly diversified sublineages and an unusual high number of widespread, often introduced weedy species. This rules out a genome skimming approach and suggests target capture methods as the more appropriate approach. We identified a new genetic marker set universally applicable across the entire Amaranthaceae s.s. lineage. The baits are based on 28 transcriptomes and a reference genome of Amaranthus hypochondriacus. A total of 10,612 orthologous and low-copy genes were identified in a previous comprehensive transcriptomic study and compared with the output of MarkerMiner. Following the genome reference, 73,262 exons were split and filtered based on criteria including a minimum length of 800 bp, less than 50% missingness per sequence,
<figure><img src="image_576.png" /></figure>

more than 2% informativeness, a minimum of
75% pairwise identity, and a requirement of at
least 15 sequences per alignment. The remaining
2,561 exons were manually checked to ensure the
quality of the loci. The final probes target a total
of 884 nuclear loci and 1.7 Mbp. Based on this set
of carefully selected loci, we reconstruct the evo-
lutionary history of the entire Amaranthaceae s.s.
lineage with the first aim to investigate the origin,
age and spread of Australian lineages of Ama-
ranthaceae s.s.

S.249.5 Ecological and
historical factors underlying
the uneven diversification
of firs in the Northern
Hemisphere

Qiaoping Xiang¹,², Jie Yang¹,²,³, David S. Gernandt⁴, Tongxin Ye¹,², Ling Yang¹,²,³, Jiaming Pan¹,²,³, Ruichen Xiang¹,²,³, Cheng Zhao⁵, Koh Nakamura⁶, Xianchun Zhang¹,², Yongbo Liu⁷, Ran Wei¹,²

1 State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing, China. 2 China National Botanical Garden, Beijing, China. 3 University of Chinese Academy of Sciences, Beijing, China. 4 Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico. 5 Institute for Environmental Decisions, ETH Zurich, Switzerland. 6 Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Japan. 7 State Environmental Protection Key Laboratory of Regional Eco-process and Function Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.

The Northern Hemisphere represents the largest
landmass and harbors the most diverse temper-
ate biomes on the Earth. Notably, species rich-
ness is unevenly distributed across regions in
the Northern Hemisphere, which is much higher
in East Asia than in North America and the Eu-
ro-Mediterranean region. However, the possible
factors underlying this pattern remain to be ex-
plor ed. Abies (Pinaceae) represents one of the
most species-rich genera of conifers, which is
consistent with the general biodiversity uneven
patterns of the Northern Hemisphere, and once
used as an important ecological proxy in esti-
mating climate changes. Therefore, Abies is an
outstanding lineage to explore the evolutionary

force underlying the heterogeneity of species di-
versity in the Northern Hemisphere. In this study,
we used the next-generation sequencing ap-
proach Hyb-seq to obtain nuclear conserved or-
tholog loci, and to reconstruct a robust phylogeny
of Abies with maximum likelihood and coalescent
analysis. The multi-peak Ornstein-Uhlenbeck
model and BayesRates revealed the significant
correlation between diversification rate changes
and niche shifts, that the ecological environment
plays an important role in firs diversification. We
also conducted multiple regression analyses and
simultaneous autoregressive and the results indi-
cated that the Abies species richness negative-
ly responds to warmer temperatures and lower
precipitation, which prefers seasonally moist and
cool temperatures. The estimated time of spe-
ciation rate change and major niche shift in the
East Asia clade coincides with the Asian monsoon
strengthening caused by orogenic events in the
Himalayas and Hengduan Mountains. We pro-
posed that the significant transition from arid to
humid and cool climates in large areas of East
Asia as well as the diverse mountain environment
in the Himalayas and Hengduan Mountains, has
triggered an acceleration of Abies diversifica-
tion. Our results unraveled that the net diversifi-
cation driven by specific environmental factors
is responsible for the fir diversity anomaly in the
Northern Hemisphere.
# S.250 LET PEOPLE COME TO BOTANY: NEW METHODS TO ENGAGE PEOPLE WITH PLANT DIVERSITY. SESSION 2

## S.250.1 Sowing the Seeds: Citizen Science and Mobile Apps in Education and Beyond

Sergio Chozas¹,², Alice Nunes¹, Helena C. Serrano¹, Fernando Ascensão¹, Susana Tapia², Cristina Máguas¹, Cristina Branquinho¹

1 Faculdade de Ciências da Universidade de Lisboa, Portugal. 2 Sociedade Portuguesa de Botânia, Portugal.

Over the last decades, there has been a sharp decline in global biodiversity. Land-use change, habitat fragmentation, and climate change are key human-induced causes contributing to the current biodiversity crisis. However, public awareness of the biodiversity crisis is low, particularly for plants, creating a barrier to their conservation. Moreover, in a world where a large part of the human population lives in urban areas, the contact of people with nature is declining, a tendency that will be exacerbated in the future. Indeed, many have highlighted the "extinction of experience" — a term for the growing alienation between people and nature — as the primary cause of this lack of public awareness of the biodiversity crisis. In this work we show how citizen science and mobile apps can be used as educational tools to raise awareness about plant diversity among students and the broader public. We examine the outcomes of three BSc-level formal education activities as well as two informal education initiatives. We discuss the potential of these approaches as educational and outreach tools and show that citizen science and mobile apps are remarkable tools for connecting students and the public with nature and engaging society in environmental challenges such as biodiversity conservation. We also explore the need for developing metrics to determine the real impact of these new approaches and propose some of them, such as an increase in the number of students in Flora disciplines and master's theses, plant conservation activism and observations in iNaturalist by former students.

## S.250.2 Green roofs in continental climates: what makes them different?

Marta Pianta¹, Mariasole Calbi¹, Enrica Roccotiello¹, Lea Margraf², Zoe Hentschel², Wolfgang W. Weisser²

1 Department of Earth, Environment and Life Sciences, University of Genoa, Genoa, Italy. 2 Technical University Munich, Terrestrial Ecology Research Group, School of Life Sciences, Freising, Germany.

Green Roofs (GRs) are Nature-based Solutions that provide habitats and support biodiversity in cities. While GRs number is rapidly increasing, their ecological characterization is still poor. In particular, while all GRs are seeded or planted with plant mixtures, the development of plant communities on GRs has rarely been investigated. To unravel relationships between GRs vegetation and structural and environmental factors, this study examined 75 GRs in the city of In golstadt, Germany. A comprehensive sampling was carried out in the summer of 2023 within plots of 1 m² located in the centre of each GR. GR size, height, soil depth, age and management regime were consid ered as predictor variables. The plant taxonomic di versity of the roof communities was calculated using Hill numbers. The main drivers of species composition were identified through a Non-Metric Multidimensional Scaling (NMDS) and selected variables were used to fit a Redundancy Analysis (RDA). GLMs were then fitted to model diversity indices and bryophyte coverage across GRs in relation to selected factors. Differences in bryophyte coverage according to management type were also assessed with a Kruskal-Wallis test. The NMDS showed that the most influential variables on GRs plant communities are age, soil depth, mowing and weeding practices (9% of the variance explained in the RDA). Plant diversity tends to increase with in creasing soil depth and GR height. Bryophyte cover decreases with increasing soil depth. In addition, bryo phyte cover is significantly different between unman aged and regularly mown or weeded GRs. Our study shows that plant communities of GRs are affected by several roof variables, and that soil depth, roof height
<figure><img src="image_577.png" /></figure>

and management strongly affect plant communities developing on the roofs. The results may provide useful insights for more environmentally and financially sustainable design and management of GRs.

### S.250.3 The time for species knowledge is now!

Åsa Krüger¹,², Stina Weststrand¹,²

1 Gothenburg Botanical Garden, Gothenburg, Sweden. 2 Gothenburg Global Biodiversity Centre, Gothenburg, Sweden.

How can we spark people's interest for the fascinating world that is Botany? The climate and the biodiversity crisis are the main focuses in both education and media. But are we prepared to tackle these important issues? To understand biodiversity, or the loss of biodiversity, it is essential to also know the building blocks of biodiversity - species! There has never been a time when species knowledge has been more important than now! How do we spread our knowledge inside and outside the classroom? As a botanical garden, we have a broad platform for communication of botanical knowledge. People arrive happy and excited and (most often) by their own choice, that's a good start! We also have strong presence on social media. By combining the digital content, podcast and personal interaction in the garden at events, lectures and guided tours, we can reach a mixed target group. This is where we can spread and encourage interest in species knowledge; give people the information they didn't know they wanted. We present challenges and new possibilities on how people can interact with botany!

### S.250.4 Surveying the scope, success, and challenges of plant conservation community science

Jessamine Finch¹, Micah Jasny¹,², Katherine F. Kucera³,⁴, Gretel Kiefer⁴

1 Conservation Department, Native Plant Trust, Framingham, Massachusetts, USA. 2 Natural Heritage & Endangered Species Program, Massachusetts Division of Fisheries & Wildlife, Westborough, Massachusetts, USA. 3 The Wetlands Initiative, Chicago, Illinois, USA. 4 Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, Illinois, USA.

Since the end of the 20th century, volunteerism has become a major component of biological conservation worldwide. Interacting factors including limited funding, availability of technology, and public interest present a unique opportunity for conservation scientists and practitioners to benefit from larger datasets with broader spatial and temporal reach than possible with professionals alone. Volunteer monitoring efforts can be considered a part of the wider, growing field of community science (a.k.a. citizen science). In tandem with benefits to science and conservation, volunteers gain hands-on research experience, scientific knowledge, outdoor opportunities, and community. While adoption of community science in plant conservation appears to be increasing over the last 30 years, the landscape has remained largely undefined. To better understand the current status of community science in plant conservation, we conducted an assessment of community science projects that conduct rare plant monitoring. Through online research and targeted outreach, we surveyed 19 project managers in the United States and Australia and close to 300 volunteers from five unique projects. We documented a spectrum of project models, bounded by semi-autonomous surveys and monitoring directly supervised by researchers. We found that volunteers contribute tens of thousands of hours to monitoring rare plants annually, representing hundreds of thousands of dollars of in-kind donations. Despite project success documented through longevity, number of volunteers, and the amount of data collected, persistent challenges including data quality, data security, and project management limit establishment of new projects and the potential of existing projects. This assessment has led to the founding of the Rare Plant Community Science Network with the goal of "improving rare plant monitoring and conservation through sharing and collaboration between community science programs." The network currently represents 38 programs spanning four countries (Canada, U.S., Australia, and South Africa) and three continents.

### S.250.5 Botanical diversity and conservation strategies in the Colombian Caribbean: the critical role of local herbaria

Andrés Orejuela¹

1 Department of Biology, University of Cartagena, Colombia.
<figure><img src="image_578.png" /></figure>

The Colombian Caribbean stands out for its immense biological richness, evidenced by diverse flora and the presence of numerous endemic species. This presentation outlines the current state of knowledge about this flora and highlights the scientific value of botanical collections in the region. The Colombian Caribbean flora faces significant threats, primarily due to anthropogenic factors such as deforestation, urbanization, and agriculture. Key mountainous regions like the Sierra Nevada de Santa Marta and the Serranía de Perijá host a unique diversity of plant formations, including the valuable páramos. In parallel, the extensive plains of the Caribbean, which make up the majority of the region, are home to equally important ecosystems such as dry tropical forests. These plains, along with the mountainous zones, form a mosaic of habitats that underscore the rich biodiversity of the Colombian Caribbean. The fragmentation and systematic destruction of these ecosystems have drastically reduced their extent, leaving less than 8% of the original dry tropical forests. This alarming situation underscores the urgency of implementing effective conservation strategies. In this context, botanical collections become critically important. The local herbaria, like the one recently established at the University of Cartagena, are fundamental for preserving knowledge of the regional flora. These centres serve as vital resources for research in taxonomy, diversity, evolution, and ecology. Beyond their academic value, the herbaria play an essential role in education and raising awareness about the importance of local flora conservation. Conservation efforts through these herbaria are a vital step towards understanding and protecting the unique biodiversity of the Colombian Caribbean. Interinstitutional collaboration and continuous commitment to botanical research and conservation are key to tackling environmental challenges and preserving this valuable natural heritage.

### S.250.6 Scientific common names (SCNs) for selected medicinal plants: an improved botany communication method

Adeyinka O. Adepoju¹, Tunde J. Ogunkunle², Abiola G. Femi-Adepoju¹, Emmanuel Ejigboye³

1 African Methodist Episcopal University, Monrovia, Liberia. 2 Ladoke Akintola University of Technology, Ogbomoso, Nigeria. 3 Edward Murrow College of

Communication, Washington State University, Pullman, USA.

New 'scientific' common nomenclatures were constructed in line with the root meanings of scientific names. Based on this study, 563 novel, scientific common names (SCN) have been created for 181 medicinal plants belonging to 79 families, in relation to their binomial nomenclature for the first time. The newly established common names have the benefit of making scientific knowledge simpler. Newly formed SCNs can be used as templates for the naming of other living things and for the creation of new, scientific local names in other languages. New 'scientific' common nomenclatures were constructed in line with the root meanings of scientific names. Based on this study, 563 novel, scientific common names (SCN) have been created for 181 medicinal plants belonging to 79 families, in relation to their binomial nomenclature for the first time. The newly established common names have the benefit of making scientific knowledge simpler. Newly formed SCNs can be used as templates for the naming of other living things and for the creation of new, scientific local names in other languages. The construction of new SCNs followed the etymologies of scientific terms. This study led to the creation of 563 new common names for 180 medicinal plants from 80 families, which were previously unknown in relation to their binomial nomenclature. The primary benefit of the recently established common names is that scientific data is presented in clear, concise language that is easy to understand. On the basis of this, it is advised to review plant common names. These new SCNs can be used as templates to generate similar names for other living things.
# S.251 ECOPHYSIOLOGICAL CHALLENGES IN THE ANTHROPOCENE. SESSION 2.

## S.251.1 Functional traits and soil water availability shape competitive interactions in a diploid-polyploid complex

Alba Rodríguez Parra¹, Javier López Jurado¹, Jesús Picazo Aragonés¹, Mario Fernández Martínez¹, Claudia Moreno Portillo¹, Anass Terrab Benjelloun¹, Enrique Mateos Naranjo¹, Francisco Balao Robles¹

1 Biología vegetal y Ecología, Universidad de Sevilla, Spain.

Although polyploid species become successfully established in the short term, only a few persist in the long term. Interaction between polyploids with their ancestral cytotypes in secondary contact zones can contribute to these extinctions. Environmental factors as water availability and functional trait divergence may influence this competitive interaction. We conducted a greenhouse competition experiment with four cytotypes (2x, 4x, 6x, and 12x) of Dianthus broteri under two contrasting water regimes. We estimated niche and fitness differences and predicted the pairwise competitive outcomes. Additionally, we explored the influence of functional traits (SLA, AN, Fv/Fm, and iWUE) on competitive interactions. Water availability modified the competitive dynamics between cytotypes and predicted competitive exclusion. Under high water availability, cytotypes with lower ploidy levels (2x and specially 4x) exhibited the greatest competitive abilities while under low water availability, the higher level cytotypes (12x, 6x) overcompeted. These differences in competitive outcomes were explained by functional traits related to competitive effects (SLA) and competition tolerance (AN, Fv/Fm, and iWUE). Our study emphasizes that the long-term fate of polyploids largely depends on water availability, with polyploids having a competitive advantage in arid environments and highlighting the role of functional traits in shaping the competitive dynamics between cytotypes.

## S.251.2 Inter- and intraspecific variability in leaf minimum conductance (gmin) in vascular plant species across five biomes

Marc Carriquí¹,², Faustino Rubio³, María Ancín⁴, Ismael Aranda², Daniela Aros-Mualin⁵, Unai Artetxe⁶, Manuel Ayuso⁷, Ángel Barón-Sola³, Ignacio Buesa⁸, F. Javier Cano², Miquel Capó⁹, Carles Cardona¹⁰,¹¹, Jaume Company¹, María del Rey², Raquel Esteban⁶, Antoni Josep Far¹, Beatriz Fernández-Marín⁶, Jaume Flexas¹, Luis Flor¹, Angie L. Gámez¹², J. Ignacio García-Plazaola⁶, Llorenç Gibanel¹, Roman Gmür⁵, M. Teresa Gómez-Sagasti⁶, Javier Gulías¹, Virginia Hernandez-Santana¹³, Antonio Hernández⁶, Laia Jené¹⁴, Rafael G. Lacalle⁶, Ana López-Ballesteros¹⁵,¹⁶, Rubén Martín-Sánchez¹⁵, Enrique Mateos Naranjo¹⁷, David Medel³, Pere M. Mir-Rosselló¹,¹¹, José Carlos Miranda³, Melanie Morales¹⁴, Lluna Morcillo¹⁸, Sergi Munné-Bosch¹⁴, Miquel Nadal¹⁵, Jorge Pallarés³, Alicia V. Perera-Castro¹⁹, Alfonso Perez-Martin¹³, Javier Pichaco¹³, Marta Pintó-Marijuan¹⁴, Rocio Ploschuk²⁰, Joan Pons¹, Jesús Rodríguez-Calcerrada³, Celia M. Rodríguez-Domínguez¹³, J. Salvador Rubio-Asensio²¹, Lorena Ruiz de Larrinaga⁶, Roberto L. Salomón³, Jaime Sebastian-Azcona¹³, David Soba²², Guillermo Toro²³, Alberto Vilagrosa¹⁸,²⁴, Sabina Villadangos¹⁴, Rosana López³

1 Grup de recerca en Biologia de les Plantes en Condicions Mediterrànies, Departament de Biologia, Universitat de les Illes Balears, Institut d'Investigacions Agroambientals i d'Economia de l'Aigua, Palma, Illes Balears, Spain. 2 Instituto de Ciencias Forestales (INIA), CSIC, Madrid, Spain. 3 Grupo de
<figure><img src="image_579.png" /></figure>

Investigación FORESCENT, Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid. 4 Instituto de Agrobiotecnología, Consejo Superior de Investigaciones Científicas-Gobierno de Navarra, Mutilva, Spain. 5 Department of Systematics and Evolutionary Botany, University of Zurich, Zurich, Switzerland. 6 Group of Biodiversity, Ecosystem Services and Ecophysiology of Stress and Pollution in Plants, Department of Plant Biology and Ecology, Faculty of Science and Technology, University of the Basque Country, P.O. Box 644, Bilbao, Spain. 7 Centro de Investigação de Montanha, Instituto Politécnico de Bragança, Campus de Santa Apolónia, Bragança, Portugal. 8 Centro de Investigación de la Desertificación (CSIC-UV-GV), Moncada, Valencia, Spain. 9 Plant & Animal Ecology Lab. Centro para la Conservación de la Biodiversidad y el Desarrollo Sostenible. Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid. 10 Centre Forestal de les Illes Balears (Menut), Institut Balear de la Natura, Palma, Spain 11 Interdisciplinary Ecology Group. Department of Biology, University of the Balearic Islands Palma, Spain. 12 Department of Agronomy, Biotechnology and Food Science, Public University of Navarre, Pamplona, Spain. 13 Irrigation and Ecophysiology Group. Instituto de Recursos Naturales y Agrobiología (CSIC), Seville, Spain. 14 Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Institut de Recerca en Biodiversitat, Universitat de Barcelona, Barcelona, Spain. 15 Departamento de Sistemas Agrícolas, Forestales y Medio Ambiente, Centro de Investigación y Tecnología Agroalimentaria de Aragón Zaragoza, Spain. 16 AgriFood Institute of Aragon - IA2 (CITA-University of Zaragoza), Zaragoza, Spain. 17 Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain. 18 Mediterranean Center for Environmental Studies, University of Alicante, Sant Vicent del Raspeig, Alacant, Spain. 19 Departamento de Botánica, Ecología y Fisiología Vegetal, Universidad de La Laguna, La Laguna, Spain. 20 Department of Agricultural and Forest Sciences and Engineering, University of Lleida-AGROTECNIO-CERCA Center, Lleida, Spain. 21 Departamento de riego, Centro de Edafología y Biología Aplicada del Segura (CSIC), Campus de Espinardo, Murcia, Spain. 22 Institute for Multidisciplinary Research in Applied Biology, Universidad Pública de Navarra, Pamplona, Spain. 23 Centro de Estudios Avanzados en Fruticultura, Las Parcelas 882, Rancagua, Chile. 24 Departament of Ecology, University of Alicante, Sant Vicent del Raspeig, Alicante, Spain.

Leaf minimum conductance ($g_{min}$) represents the vapor diffusion conductance through the surface with closed stomata, encompassing cuticle and “leaky” stomata. It stands as a critical functional trait defining the dehydration rate after stomatal closure and its capacity to overcome long-lasting droughts and heatwaves. While other traits related to drought resistance (e.g., wilting point, embolism vulnerability) are known to vary with climate, the climate-dependent variation in $g_{min}$ remains poorly understood, despite being recognized to display significant interspecific variability and

plasticity to growth conditions. Our study encompasses a diverse array of over 300 species growing under natural conditions, including angiosperms, gymnosperms and pteridophytes, as well as various growth forms—from trees to herbs—and leaf habits. To capture the interspecific variability and plasticity in $g_{min}$, we sampled plants from more than 50 locations spanning a steep mean annual temperature and precipitation gradient in Europe, ranging from 2.4 to 19.6 °C, and 250 to 2200 mm, respectively. Sampling was conducted on current-year, sun-adapted leaves during the summer of 2023. Measurements also included leaf dimensions, stomata distribution, trichome presence, and leaf dry mass per area. This broad sampling allows to explore the extent of $g_{min}$ variability and its potential correlations with climatic conditions across five biomes in a large spectrum of plant diversity. In order to explore intraspecific variability, we selected four widely distributed species representing different ecological strategies—Quercus ilex (evergreen angiosperm), Ailanthus altissima (deciduous angiosperm), Pinus halepensis (evergreen gymnosperm), and Pteridium aquilinum (fern)— and measured them in over 10 locations. Results showed a strong intra- and inter-specific variability in $g_{min}$ as well as significant plasticity. This study provides valuable insights into the adaptive responses of plants to climate, enhancing our understanding of the functional significance of $g_{min}$ in the context of climate change adaptation.

### S.251.3 Stomata are driving the direction of carbon dioxide induced water-use efficiency gain in selected tropical trees in Fiji

Wuu Kuang Soh¹, Charilaos Yiotis², Michelle Murray³, Sarah Pene⁴, Alivereti Naikatini⁵, Johan A. Elkink⁶, Joseph D. White⁷, Marika Tuiwawa⁵ and Jennifer C. McElwain³

1. National Botanic Gardens, Glasnevin, Dublin, Ireland.
2. Department of Biological Applications and Technology, University of Ioannina, Ioannina, Greece.
3. Department of Botany, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland.
4. School of Geography, Earth Science and Environment, University of the South Pacific, Laucala Campus, Suva, Fiji.
5. South Pacific Regional Herbarium, University of the South Pacific, Laucala Campus, Suva, Fiji.
6. School of Politics and International Relations, University College Dublin, Belfield, Ireland.
7. Department of Biology, Baylor University, Waco, TX, USA.
<figure><img src="image_580.png" /></figure>

To date, the effects of decadal scale rising atmospheric CO₂ concentration on plant gas-exchange characteristics in the tropics are largely unknown. This research provides a rare insight on the little-known long-term impact of rising atmospheric CO₂ on plant water-use and conductance of tree species in Fiji. Our study focuses on five tree species from the South Pacific Islands, a region that is particularly vulnerable to the impact of global warming. This is the first known study on the long-term physiological response of native plants to climate change in the region. Studying this long-term trend using herbarium records is challenging due to trait intraspecific variation. We assessed the impact of atmospheric CO₂ concentration rise of about 95 ppm (1927-2015) on intrinsic water-use efficiency (iWUE) and theoretical maximum stomatal conductance of five tropical tree species in Fiji using isotopic composition and stomatal traits of herbarium leaves. Empirical results were compared with simulated values using models that uniquely incorporate intraspecific variation of empirical maximum stomatal conductance responses and specimen- or species-specific parameterization. While the magnitude of iWUE and maximum stomatal conductance response is species-specific ranging from strong to negligible, our findings indicate that the impact of stomata on determining the direction of iWUE response becomes apparent in situations where there is a consistent trend in photosynthesis. Generally, a stronger increase in iWUE was accompanied by a stronger decline in maximum stomatal conductance. This study demonstrates that incorporation of adaptations in maximum stomatal conductance, via changing size and/or density of stomata, in simulation is necessary for assessing an individual species iWUE response to changing atmospheric CO₂ concentration.

### S.251.4 The role of the plants' defense dimension on shaping abiotic stress tolerance of woody plants

Andrea Cerdeira-Pérez<fnref n="1" />, Lauri Laanisto<fnref n="2" />, Giacomo Puglielli<fnref n="1" />

Plants are members of a biodiverse community where interactions can either benefit or negatively impact plant fitness. Herbivore insects (negative interaction)

exert a strong selective pressure on plant defensive strategies. At the same time, the production and maintenance of defenses is energetically costly and depends on habitat quality, including resource and non-resource stress levels. Accordingly, under high herbivory pressure, plants allocate resources to defense against phytophagous insects, possibly limiting resource allocation to tolerate abiotic stressors. In other words, biotic and abiotic stress tolerance can exhibit a trade-off. In that context, we aim to elucidate the role of biotic stress (defense dimension) on shaping a species abiotic tolerance syndrome. The so-called Stress Tolerance Space (STS) was recently described as a trade-off model defining the limits of ecophysiological tolerances of Northern Hemisphere woody plants towards four major abiotic stresses (shade, drought, cold and waterlogging). A plant tolerance to a given abiotic stress is constrained by other co-occurring abiotic and biotic factors and, therefore, the integration of key ecological dimensions with the STS model would allow to disentangle the multidimensional nature of woody plants' adaptations to abiotic stress. To that end, we have compiled data on traits related to the feeding ecology (e.g., feeding guild, hostplant specialization) of 6000 species of phytophagous Lepidoptera and Hymenoptera associated with the woody plant species under study within the abovementioned STS model. By exploring how insect feeding traits distribute within the STS, we provide evidence of a complex association between particular sets of feeding traits and specific stress tolerance strategies in woody plants of the Northern Hemisphere, thereby gaining insights about the significance of the biotic-abiotic stress tolerance trade-off.

### S.251.5 The above- and below-ground segregation of functional space of oak seedlings responds to native habitats

Maribel Arenas-Navarro<fnref n="1" />,<fnref n="2" />, Ken Oyama³, Fernando Pineda-García³, Andrés Torres-Miranda³, Horacio Paz<fnref n="1" />, Felipe García Oliva<fnref n="1" />

<footnote n="1">1 Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain.</footnote>

<footnote n="2">2 Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia.</footnote>

<footnote n="1">1 Instituto de Investigaciones en Ecosistemas y Sus tentabilidad, Universidad Nacional Autónoma de México, Michoacán, México. 2 Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, México, México. 3 Escuela Nacional de Estudios Superiores, Unidad Morelia, Universidad Nacional Autónoma de México, Michoacán, México.</footnote>
<figure><img src="image_581.png" /></figure>

Seedling growth and morphology reflect functional responses to habitat because their establishment relies on the development of resource-acquiring organs and their capacity to respond to the environment. Oak species contribute significantly to above-ground biomass and biodiversity in Northern Hemisphere Forest ecosystems. Although morphological and physiological differentiation has been studied in oaks, it is necessary to conduct studies to analyze the ecological strategies at the seedling stage. In this study, we conducted an experiment under controlled conditions to assess how interspecific variation in functional traits of oak seedlings varies in relation to their native climates. We selected three oak species from dry lowland forests and three from mesic highland forests of Mexico. We analyzed the trade-offs among leaves, stems, and roots that drive functional differentiation between dry and mesic oak species. We examined trait-by-trait relationships, constructed interaction trait networks, and then quantified the overlap of functional space at both the species and environmental group levels. Our results showed significant differences among environmental groups, primarily in leaf carbon:phosphorus ratio, stem water content, and biomass allocation. Oak species from dry environments allocate biomass to roots to obtain water and nutrients as a drought adaptation. Meanwhile, mesic oak species allocate more biomass to leaves, with higher leaf nitrogen and phosphorus concentrations and stem water content. Both environmental groups showed trait-by-trait relationships; however, we found that the pattern of coordination of traits was different between the dry and mesic oaks. This supports the idea that the selective value of the same traits differs under different environmental conditions. Finally, we found significant segregation of the functional space among species in the same environmental group, highlighting the diversity of ecological strategies in oaks. Variations in plant functional traits and different elemental compositions among oak species promote diversity in ecological strategies.
**S.252 THE EVOLUTION AND BIOGEOGRAPHY OF APOMICTIC PLANTS. SESSION 2**

**S.252.1 Phylogenomics and morphometric-environmental modeling unraveled reticulate polyploid evolution of the Ranunculus auricomus complex**

Karbstein, Kevin<sup>1,2,3*</sup>, Tomasello, Salvatore<sup>1</sup>, Hodač, Ladislav<sup>2</sup>, Wagner, Natascha D.<sup>1</sup>, Marinček, Pia<sup>1</sup>, Barke, Birthe Hilkka<sup>1</sup>, Paetzold, Claudia<sup>1,4</sup>, Bradican, John P.<sup>1</sup>, Wäldchen, Jana<sup>2</sup> & Hörandl, Elvira<sup>1</sup>

1 University of Göttingen, Albrecht-von-Haller Institute for Plant Sciences, Göttingen, Germany. 2 Max Planck Institute for Biogeochemistry, Jena, Germany. 3 Technical University of Ilmenau, Institute for Computer and Systems Engineering, Ilmenau, Germany. 4 Senkenberg Naturhistorische Sammlungen, Dresden, Germany. *kkarb@bgc-jena.mpg.de.

Hybridization, polyploidization, and/or apomixis represent important evolutionary forces of plant speciation. However, consequences of partly overlapping, intricate evolutionary processes are still poorly understood for non-model, neopolyploid plant groups. Analytical challenges are attributable to high heterozygosity, low genetic divergence, and missing information on progenitors species, ploidy levels, and reproduction modes. To tackle this, we selected the large European *Ranunculus auricomus* species complex, comprising five newly circumscribed sexual species and >800 polyploid taxa/morphospecies. Subgenomic (97,312 RAD-Seq loci, 576 nuclear genes, and 71 plastid regions), flow cytometric leaf/seed (1,474/1,075 screened individuals), geometric morphometric (1587-1880 landmarked individuals per trait), and abiotic environmental datasets were collected from 75 polyploid apomictic taxa and four putative sexual progenitor species. In this talk, an innovative taxonomic workflow will be presented, which includes phylogenomic tree, structure, network, and SNP-origin

analyses, and genomic-morphometric-environmental multivariate modeling. Results consistently showed polyphyly and only 3-5 supported groups instead of 80 polyploid morphospecies. Each group contained an extant sexual progenitor species, and surprisingly, one group possessed a yet unknown (probably extinct) progenitor. Combined multi-genomic analyses demonstrated predominantly allopolyploid origins, each involving 2-3 different diploid sexual progenitors, potentially during interglacial periods. Young allotetraploids showed subgenome dominance and non-hybrid SNPs, suggesting substantial post-origin (e.g., hybrid segregation) and little lineage-specific evolution. Sexual progenitors occupied a much smaller range in southern and central Europe, whereas three-times more heterozygous polyploid and predominantly obligate apomictic derivatives expanded their range towards northern and northeastern Europe characterized by more temperature variable habitats. Allopolyploid apomicts, compared to their diploid sexual progenitors, resemble a mosaic of new, more stress-tolerant genotypes with morphologically intermediate to transgressive biotypes often outside the progenitor's ecological niches, explaining the observed geographic parthenogenesis scenario. The joint evaluation of phylogenomic, cytological, morphological, and ecological data supports a revision of the purely descriptive, subjective traditional morphological classification.

**S.252.2 Integrative taxonomy studies to disentangle Hieracium tenuiflorum Arv-Touv. (Asteraceae) diversity in Italy**

Fainelli Federico¹, Giacomo Baldesi¹, Giulia Ginelli¹, Carla Lambertini², Orsenigo Simone¹

1 University of Pavia, Pavia, Italy. 2 University of Milan, Milan, Italy.
Hierакium L. has extreme morphological variation caused by complex reproductive strategies, inter-specific hybridization and polyploidization. The genus includes few sexual diploids and numerous apomictic polyploids (Mraz & Zdvořák 2019). Taxonomy and systematics of this group are extremely complex and poorly investigated. *Hierакium. tenuiflorum* Arv.-Touv. belongs to *H. murorum* L group (sect. *Hierакium*), and occurs in Alps and Apennines, where it grows in forest margins and along roadsides between 200-1800 m a.s.l. Currently, there are 6 subspecies ascribed to *H. tenuiflorum*. Most of them were originally described for Italian localities across the Alps. However, the current classification for these taxa is based only on morphology and information on current distribution, ploidy level or genetic diversity is lacking. To disentangle the taxonomic diversity of the species, we used an integrated taxonomic approach, including nomenclatural investigation on herbarium specimens, morphometry, chromosome counts, genome size estimation and molecular systematics. Recently collected plants from *loci classici* of *H. tenuiflorum* subspecies and from different localities in Alps and Apennines were investigated. These studies revealed a high variability in ploidy level in *H. tenuiflorum*. For the first time, at least three diploid *H. tenuiflorum* populations were reported in the Southern Alps. Morphometric analyses showed morphological differences between subspecies despite morphological clusters mainly overlapped, suggesting high morphological similarity. Finally, we performed molecular investigations using three plastid intergenic spacers (trnH-psbA, trnT-trnL, and trnV-ndhC) and ten nuclear microsatellites to evaluate the phylogenetic relationship between sampled populations.

References: Mraz, P., & Zdvořák, P., (2019) *Ann. Bot.*, 123(2), 391-403.

### S.252.3 The hybrid origins of African forage crop grasses in the genus Urochloa (Panicoideae, Poaceae)

Lizo E. Masters¹,², Paulina Tomaszewska¹,³, Trude Schwarzacher¹,⁴, Alexandre R. Zuntini², Pat Heslop-Harrison¹,⁴, Maria Vorontsova²

1 University of Leicester, Leicester, UK. 2 Royal Botanic Gardens, Kew, Richmond, UK. 3 University of Wrocław, Wrocław, Poland. 4 South China Botanical Garden, Guangzhou, China.

African grasses in the genus Urochloa (Brachiaria) have been recognised for their forage crop potential as early as the 18th century. Three closely related African

species (U. brizantha, U. decumbens, and U. ruziziensis) dominate Urochloa breeding and are hybridized to produce the world's most commercially important tropical forage cultivars. These three grasses form a naturally occurring species complex characterised by diverse ploidy levels, overlapping morphologies, and sexual and asexual reproduction. The reticulate evolution of U. brizantha, U. decumbens and U. ruziziensis, and their phylogenetic relations within Urochloa remain unclear. Elucidating this history will greatly benefit future breeding projects. We inferred a species level phylogeny for Urochloa using target enrichment and RNA-seq data from Kew Herbarium and Centro Internacional de Agricultura Tropical (CIAT) accessions. Additionally, we estimated ancestral states for important forage traits using our phylogeny. Finally, we investigated reticulate evolution in U. brizantha, U. decumbens, U. ruziziensis and their closest wild relatives using phylogenetic networks and fluorescent in-situ hybridization (FISH). Our analysis revealed the independent evolution of five forage clades across Urochloa. Urochloa brizantha, U. decumbens, and U. ruziziensis form a well-supported clade with two wild relatives, U. eminii and U. oligobrachiata. Phylogenomic networks and FISH analysis confirm that U. brizantha and polyploid U. decumbens are hybrid species that share at least one parental lineage. Further, diploid U. decumbens and polyploid U. decumbens belong to separate lineages, which is supported by morphological data, chloroplast phylogenies, and previous population genetic and cytological work. We found evidence of reticulate evolution between polyploid U. decumbens and the lineage containing diploid U. decumbens and U. ruziziensis. The reticulate evolution of U. brizantha is more complex as diploids and polyploids share a single origin. Our study demonstrates that multiple lines of evidence (morphological, phylogenetic, cytological) are required to disentangle highly reticulate species complexes.

### S.252.4 "Pseudos corner" – morphometrics and distribution of Dryopteris pseudocomplexa and Dryopteris pseudodisjuncta in the UK and Ireland

Alison Evans¹, Libor Ekrt², Roger Golding, Sven Batke¹, Paul Ashton¹

1 Edge Hill University, Ormskirk, UK. 2 University of South Bohemia, Ceske Budejovice, Czech Republic.
<figure><img src="image_582.png" /></figure>

The scaly male ferns of the *Dryopteris affinis* (Lowe) Fraser-Jenk. complex cause problems for taxonomists because of their hybrid origins and partly apomictic, partly sexual methods of reproduction. The work presented is part of a larger study of this complex in the UK and Ireland, combining morphometrics and flow cytometry. *Dryopteris pseudocomplexa*, previously known informally as 'morphotype Arranensis', was published by Fraser-Jenkins as a subspecies of *D. cambrensis*, with records on Skye, Arran, and two locations in Ireland. In 2016 it was discovered to be a fertile tetraploid. It was published by Sell as a species. There are also reports of a similar fertile tetraploid taxon from the Härz mountains, the Vosges, and from Romania. *Dryopteris pseudodisjuncta* was first discovered in the UK in 2008, in Kirkbean Glen, Scotland, where there are also records of *D. pseudocomplexa*. It has subsequently been found on Arran and at Strome ferry, Scotland, where *D. pseudocomplexa* is also recorded, and in Cumbria and Somerset. *D. pseudodisjuncta* is a triploid apomict, and also produces male gametes that can hybridise with sexual species. Results of the morphometric analysis, and the current distribution of these two taxa in the UK and Ireland will be presented, together with identification guides to distinguish these taxa from other scaly male ferns. Samples for DNA sequencing from this study will be provided for a study led by Michael Kessler, Zurich, which may reveal whether these two taxa are related. Alternatively, they may occur together because of their preference for an Atlantic climate.

### S.252.5 The cost of co-occurrence: pollen from apomicts negatively impacts the fitness of sexuals in an open-pollinated common garden

Gracy Buckholtz¹, Max W.R. Gray¹, Jeannette Whitton¹

1 Department of Botany, The University of British Columbia.

Diverse factors have the potential to explain geographical parthenogenesis, the tendency for related sexual and apomictic forms to occupy distinct ranges. Apomicts are expected to have a colonization advantage relative to obligately outcrossing sexuals, but if this advantage is purely demographic,

we might expect sexuals to 'catch up' over time and colonize sites where apomicts have established. Where this is not the case, it could reflect ecological and/or additional life history divergence that precludes coexistence. Asymmetrical reproductive interference is an additional or alternative mechanism that may prevent invasion by sexuals into apomictic sites, through the action of pollen from apomicts reducing the reproductive fitness of sexual outcrossers. *Townsendia hookeri* (Asteraceae) includes obligate apomictic autotriploid and sexual outcrossing diploid populations that display a classical pattern of geographical parthenogenesis along the eastern slope of the Rocky Mountains, from Colorado, USA to British Columbia, Canada. The two forms overlap in range in southern Wyoming, but co-occurrence is rare. Transplants across the range reveal that sexuals can persist in sites occupied by apomicts. We measured the strength of reproductive interference (RI) by analyzing progeny produced in a mixed, open-pollinated common garden located in the zone of range overlap. Seed set of sexuals declined as a function of their proximity to apomicts. We used genomic markers (SNPs) to infer the parentage of progeny arrays from sexual maternal plants, using the programs BORICE to estimate the mating system and HIPHOP to determine parentage. We detected low levels of hybrid formation, and, contrary to previous interpretations from controlled crosses, no evidence of induced selfing. Our findings point to significant negative impacts of co-occurrence via RI, even though sexuals were roughly equal in number to apomicts in our garden. This suggests that, in some cases, reproductive interference may be key to explaining geographical parthenogenesis.

### S.252.6 Deconstructing apomixis in angiosperms: from macroecological patterns to microevolutionary processes

Diego Hojsgaard 1; Agostina Sassone 1; Piyal Karunarathne 2

1 Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany

2 Institute of Population Genetic, Heinrich-Heine-Universität, Düsseldorf, Germany
<figure><img src="image_583.png" /></figure>

Mapping the geographical distribution of phyloge-
netic traits helps visualize macroecological patterns
(above species regional level) and understand how
long standing microevolutionary processes (below
species level) shape evolution. These processes are
determined by mutation, genetic drift, gene flow,
non-random mating, and natural selection, leading
to the patterns we see today.

We reviewed global occurrences of apomictic spe-
cies and mapped them according to the Tree_
of_Life 3.0. Apomixis (asexual seeds), develops by
sporophytic (adventitious embryony) or gameto-
phytic (apospory or diplospory) pathways. Almost
1500 species show evidence of apomixis and c.230
species have anecdotal evidence of apomixis. Most
apomicts occur in Asteraceae, Rosaceae and Poa-
ceae, and 6 families have at least 50 apomictic spe-
cies whose distribution varies significantly among
continents. A correlation between developmental
phenotypes among apomictic species and families
suggests developmental constraints on phenotyp-
ic variability, adding to the recognized association
between apomixis-derived biodiversity and general
biodiversity.

To bridge the gap between microevolutionary pro-
cesses and macroecological patterns and under-
stand the role of apomixis in speciation, we took
Paspalum intermedium a grass species with sexu-
al diploids and apomictic tetraploids ecologically
differentiated along a latitudinal gradient in South
America&ndash; and use population-level ge-
nomics (Genotyping-by-Sequencing), reproduc-
tive and environmental/occurrence data (Ecolog-
ical-Niche-Modelling) to assess microevolutionary
processes. Diploids are genetically less variable
than tetraploids and shows a narrow diploid gene
pool from which tetraploids arise in P.intermedium.
STRUCTURE analysis shows three consistent K values
that relate to ploidy states, lineage ancestry and
ecological attributes. Principal component and min-
imum spanning network analyses support a narrow
cluster of diploids, and more diverse tetraploid lin-
eages differentiated by geographic region (North/
Centre/South) and cytotype co-existence (sym-
patry/parapatry/allopatry). Reproductive mode ra-
tios (sexual/apomictic) associate to environmental
variables and within population clonal diversity in
marginal areas.

Our analyses suggest that differences in gene flow
conditions promote intraspecific geographic/ge-
netic differentiation within and between cytotypes,
supporting early steps of speciation.
# S.253 HABITAT-BOUND BRYOPHYTE EVOLUTION

## S.253.1 Haplotype variation in mosses bound to niche adaptation

Lars Hedenäs¹, Flavien Collart²

1 Swedish Museum of Natural History, Stockholm, Sweden. 2 University of Lausanne, Lausanne, Switzerland.

Thanks to molecular information, numerous new bryophyte species, both morphologically recognizable and cryptic ones were discovered during the last decades. Some of the new species are restricted to specific habitats, but what about haplotypes, haplotype groups, or lineages within species? Haplotype variation within bryophyte species was often used to infer migration routes of populations, population histories, and similar aspects. Much less often the focus was on correlations with habitat or potential niche adaptations or intraspecific habitat diversification. Still, we should expect these to occur when different populations adapt to environmental conditions and sometimes as part of speciation. By not considering this aspect, we may draw incorrect conclusions regarding which factors explain observed patterns of bryophyte haplotype variation and thus, predictions in species/haplotype response to climate change. Here we explore whether certain haplotypes, haplotype groups, or lineages in mosses are or may be associated with specific environmental niches, sometimes contrasting this with geographical patterns. Further, we discuss how correlations between haplotypes and habitat parameters could be explored in greater detail in the future, including important caveats – for example, factors like the number of samples and sampling strategies.

## S.253.2 Disentangling habitat adaptation in species of Sphagnum magellanicum complex in North America

Marta Nieto-Lugilde¹, Diego Nieto-Lugilde², Bryan T. Piatkowski³, Aaron M. Duffy¹, Blanka Aguero¹, A. Jonathan Shaw¹

1 Department of Biology, Duke University, Durham, USA. 2 Departamento de Botánica, Ecología y Fisiología Vegetal, Universidad de Córdoba, Córdoba, Spain. 3 Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, USA.

Evolutionary drivers play a pivotal role in shaping biodiversity and influencing how species adapt and change over time. The process of habitat adaptation and evolution helps species better fit their environments, increasing their chances of survival and successful reproduction. Sphagnum species are remarkable in their ability to construct and modify their own niches, which are often well differentiated among species. Nevertheless, the scarcity of morphological characters that separate the species poses a challenge in identifying ecological traits crucial for understanding their evolution and systematics. A current contentious topic revolves around the classification of the widely distributed S. magellanicum into several morphologically indistinguishable taxa. The recent addition of two newly described species brings the count of North American species to four: S. diabolicum, S. divinum, S. magniae, and S. medium. Sphagnum, especially the S. magellanicum complex, has been developing as a model group for ecological genomics. To explore differences among these cryptic species in microhabitats and climate niches, we developed barcode markers and used RADseq analyses on 808 collections from 119 sites across eastern North America. Microhabitats, classified by hydrology and shade, alongside hierarchical modeling of species communities, were assessed for niche variation among species. Surprisingly, S. diabolicum showed not significant responses to any variable, whereas the other complex members exhibited diverse responses. Climatic variables
<figure><img src="image_584.png" /></figure>

strongly influenced *S. magniae* but less so for *S. diabolicum*, *S. divinum*, and *S. medium*. Micro-habitat variables minimally affected occurrence variation for all species, whereas random variables (sample and locality) explained significant variation for *S. diabolicum*, *S. divinum*, and *S. medium*. These results suggest that there are still unmeasured but important ecological traits impacting species occurrence. Our findings underscore the intricate interplay between species and their environments, emphasizing the varying impacts of climate and local factors on *Sphagnum* species.

### S.253.3 Parallel evolution in the genus Ulota (Orthotrichaceae, Bryophyta) under hyper-humid oceanic climates of the southern hemisphere

Ricardo Garilleti¹, Isabel Draper²,³, Juan A. Calleja²,³, Francisco Lara²,³

1. Departamento de Botánica y Geología, Universidad de Valencia, Spain. 2. Departamento de Biología, Universidad Autónoma de Madrid, Spain. 3. Centro de Investigación en Biodiversidad y Cambio Global, Universidad Autónoma de Madrid, Spain.

The subfamily Orthotrichoideae, comprising 14 genera and approximately 360 species, plays a significant role in epiphytic communities within temperate regions and high tropical mountains worldwide. Four genera notably contribute to the subfamily's diversity, accounting for around 94% of its species: *Orthotrichum* (ca. 110 taxa), *Zygodon* (80), *Lewinskya* (75), and *Ulota* (70). The latter genus boasts a subcosmopolitan distribution but stands out for its greatest diversity in the hyper-humid oceanic-temperate climates of the southern hemisphere. In western Patagonia, thriving within these conditions, Valdivian temperate forests and Magellanic subpolar forests host 23 recognized *Ulota* species so far. All these species are endemic to the area, exhibiting remarkable and rare dispersion-related adaptation patterns that could have emerged during radiative processes. Many species show adaptations that limit spore release, such as oversized endostome segments or capsule mouth contraction. Moreover, large spores are very common, and among Patagonian *Ulotae* the abundance of spores with endogenous ger-

mination (multicellular spores) stands out. Despite being an uncommon feature in the genus, this trait has appeared in up to six species in Patagonia. Large and heavy spores as those found here might face challenging long-distance dispersal. Arguably, both climatic preferences and dispersal limitations could be linked to an evolutionary pressure for spores to remain within favorable locations, particularly in this territory where strong winds can transport propagules to adverse environments, including the nearby ocean. In addition, rapid germination significantly aids the establishment of new individuals in similar and suitable conditions. These adaptations, whether occurring as syndromes or in isolation, are also observed in other regions, such as Australasia, China, or Japan. Current data suggest that this intercontinental pattern might reflect parallel evolution that arises from homoplasy, which is common in the family.

### S.253.4 Habitat-bound evolution in epiphyllous leafy liverworts of the Lejeuneaceae

Julia Bechteler¹, Adriel Sierra², Alfons Schäfer-Verwimp³, Gaik Ee Lee⁴, Kathrin Feldberg⁵, Alexander Schmidt⁵, Gordon Burleigh⁶, Stuart McDaniel⁶, Christine Davis⁶, Emily Sessa⁶, Dietmar Quandt⁷, Juan Carlos Villarreal²

1. Plant Biodiversity and Ecology, Institute for Environmental Sciences, RPTU University of Kaiserslautern-Landau, Landau, Germany. 2. Département de Biologie, Université Laval, Québec, Québec, Canada. 3. Mittlere Letten 11, 88634 Herdwangen-Schönach, Germany. 4. Faculty of Science and Marine Environment/Institute of Tropical Biodiversity and Sustainable Development, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia. 5. Georg-August-Universität Göttingen. 6. Department of Biological Sciences, University of Florida, Gainesville, FL, USA. 7. Nees-Institute for Plant Biodiversity, University of Bonn, Bonn, Germany.

The leafy Lejeuneaceae is the largest family of liverworts with some 1,900 species in 88 genera and comprise a high morphological and ecological diversity in tropical and sub-tropical ecosystems. Most species have an epiphytic lifestyle with a rather large proportion of species adapted to epiphyllous microhabitats. Specific characteristics of epiphytic and epiphyllous Lejeuneaceae are, among others, a
<figure><img src="image_585.png" /></figure>

small size, rhizoid discs, inflated leaf lobules and a short life cycle. The evolution of these epiphyllous and epiphytic lineages with their morphological and life history traits, as well as habitat transitions from terrestrial to epiphytic within the Lejeuneaceae is still poorly understood as a well-supported backbone phylogeny is lacking for this family. Beside exploring large Sanger-Sequencing datasets of nuclear and plastic markers, we use nuclear target enrichment data based on the GoFlag probe kit to untangle the evolutionary history of Lejeuenaceae that started during the Jurassic and Cretaceous. Our study will give novel insights into the evolution of potential habitat-bound life-history traits associated with the independent colonization of unstable epiphyllous habitats by several Lejeuneaceae lineages.

## S.253.5 Effect of niche on the epiphytic bryophyte community in a tropical rainforest of the Amazon

Laura V. Campos¹, Emanuel A. Cataño², Jaime Uribe²

1 Escuela de Ciencias Básicas y aplicadas, Universidad de La Salle, Bogotá, Colombia. 2 Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá, Colombia.

This study evaluated the presence and distribution of epiphytic bryophyte species in a vertical gradient based on the influence of niches associated with a tropical rainforest in the Colombian Amazon. The vertical gradient evaluated included 16 phrophytes and 16 decaying fallen logs. Each fallen log was considered as a zone (Z1), and in the case of the phrophytes six height zones (Z2 - Z7). Each zone (Z1 - Z7) was surveyed in a 10 cm2 plot, for a total of 192 sampling units (96 for phrophytes and 96 for logs). The taxonomic and floristic composition yielded a total of 120 bryophyte species, corresponding to 81 liverworts and 39 mosses. Species richness and diversity was quite similar between fallen logs and phrophytes; however, differences in species composition were evident. Of the total number of species identified, only 44 species were shared between fallen logs and phrophytes. Of the shared species, 16 were widely distributed, occurring in almost all height zones of the phrophytes, suggesting a wide tolerance of the species to changes in microclimatic and physical conditions of the environment and substrate; 20 species were restricted to the first

zones of the tree, without reaching the canopy, and finally, eight species were shared between fallen trunks and the phrophytes. Species were identified as being distributed in a free vertical zonation pattern along the host trees. By comparing the data obtained with regional studies, it could be confirmed that the niche assemblage is driving the species composition of epiphytic bryophyte communities at local and regional scales.

## S.253.6 Epigenetic and transcriptomic changes of amphibious liverwort Riccia fluitans during transformation from land to water form

Jakub Sawicki¹, Mateusz Maździarz¹, Mateusz Kurzyński¹, Łukasz Paukszto¹, Katarzyna Krawczyk¹, Paweł Sulima¹, Monika Szczecińska¹

¹Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Poland.

Amphibious plants, adept at thriving in the transition zone between terrestrial and aquatic environments, exhibit remarkable adaptability by adjusting their morphology and physiology to fluctuating environments. Riccia fluitans, an aquatic liverwort, serves as an excellent example. This species can grow as floating mats in water or on moist land, demonstrating its versatile adaptability. In our study, we employed genomics and transcriptomics approaches to shed light on the molecular mechanisms that underpin this adaptation. To assemble and annotate the Riccia genome, we utilized nanopore-based native DNA and RNA sequencing, nanopore full-length cDNA transcript sequencing, Illumina-based RNA-seq and DNA-seq of paired-reads, and Hi-C libraries. The genome of Riccia fluitans was 448 Mbp, scattered over 8 chromosome-scale contigs. Interestingly, the genome size was double that of Marchantia polymorpha, mainly due to the expansion of transposons. By comparing the water and land forms of Riccia fluitans, we identified over a thousand differentially expressed genes involved in a variety of biological processes. Our analysis of alternative splicing (AS) revealed over 800 splicing events with significant inclusion levels that differentiated the water and land forms. The majority of these events were classified
<figure><img src="image_586.png" /></figure>

as intron retention (RI), followed by alternative 3' splice site (A3SS) and alternative 5' splice site (A5SS). The least frequent AS events were exon skipping (SE) and mutually exclusive exons (MXE). We also applied native, direct RNA sequencing to identify m6A sites along the transcriptomes of both water and land forms. This revealed 152 methylated sites across

110 genes in the water form and 25 modified sites across 18 genes in the land form. Interestingly, even among the shared genes (16), different adenosines were methylated in the compared ecotypes. This study thus provides a comprehensive insight into the molecular mechanisms underlying the aquatic adaptation in *Riccia fluitans*.

# S.254 NEW INSIGHTS ON BIG PLANT GENERA 2: GENOMICS & TRAIT EVOLUTION

## S.254.1 Discovery of a major gene behind prickles, an important plant innovation, in Solanum (Leptostemonum Clade)

James W. Satterlee¹,², David Alonso³, Pietro Gramazio³, Jia He¹,², Andrea Arrones³, Gloria Villanueva³, Mariola Plazas³, Katharine Jenike⁴,⁵, Srividya Ramakrishnan⁴,⁵, Matthias Benoit⁶, Iacopo Gentile¹,⁷, Anat Hendelman¹,², Hagai Shohat¹, Blaine Fitzgerald¹,², Gina M. Robitaille¹,², Yumi Green⁸, Kerry Swartwood⁸, Edeline Gagnon⁹, Rebecca Hilgenhof⁹, Trevis D. Huggins¹⁰, Georgia C. Eizenga¹⁰, Nils Stein¹¹,¹², Shengrui Yao¹³,¹⁴, Clement Bellot¹⁵, Mohammed Bendahmane¹⁵, Sandra Knapp¹⁶, Tiina Särkinen⁹, Joyce Van Eck⁸,¹⁷, Michael Schatz⁴,⁵, Yuval Eshed¹⁸, Jaime Prohens³, Santiago Vilanova³, Zachary B. Lippman¹,²,⁷

1 Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA. 2 Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA. 3 Universitat Politècnica de València, Valencia, Spain. 4 Department of Computer Science, Johns Hopkins University, Baltimore, MD, USA. 5 Department of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA. 6 INRAE, CNRS, Laboratory of Plant-Microbe Interactions, Toulouse, France. 7 School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA. 8 Boyce Thompson Institute, Ithaca, New York, USA 9 Royal Botanic Garden Edinburgh, Edinburgh, UK. 10 USDA-ARS, Dale Bumpers National Rice Research

Center, Stuttgart, AR, USA. 11 Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany. 12 Department of Crop Sciences, Center for Integrated Breeding Research, Georg-August-University, Göttingen, Germany. 13 Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM, USA. 14 Sustainable Agriculture Science Center, New Mexico State University, Alcalde, NM, USA. 15 Laboratoire Reproduction et Developpement des Plantes, INRAE, CNRS, Université de Lyon, Ecole Normale Superieure de Lyon, Lyon, France. 16 Natural History Museum, London, UK. 17 Plant Breeding and Genetics Section, Cornell University, Ithaca, NY, USA. 18 Department of Plant and Environmental Sciences, The Weizmann Institute of Science, Rehovot, Israel.

Solanum is one of the largest genera in the plant kingdom with approximately 1,250 species. The largest monophyletic group within Solanum is the Leptostemonum Clade, with more than 500 species. A distinctive characteristic of this clade is the presence of epidermal prickles on vegetative organs; these are a synapomorphy of the Clade and represent a single origin evolutionary innovation in the genus. Prickles have been lost independently in several taxa. In cultivated species, breeders favored selection of prickleless (pl) materials during crop domestication. Interspecific mapping populations between pl eggplant (Solanum melongena) and wild prickled species revealed that the pl phenotype is recessive and consistent with one Mendelian locus. Advanced backcrosses of prickle-bearing wild species into the S. melongena background pointed to a region at the end of chromosome 6 containing the causal genetic locus. Fine mapping of the region narrowed the causal interval to a 600 kb genomic region containing 13 annotated genes that included a LONELY-GUY (LOG) cytokinin biosynthesis gene harboring a splice-site mutation. Other prickleless cultivated eggplants were found to have either splice-site mutations (S. macrocarpon) or a deletion (S. aethiopicum) in this gene, identifying it as PL.
Sequencing of PL in prickleless species from the Leptostemonum clade revealed 15 independent mutations (i.e., frameshift, splice-site, TE insertion, and deletion alleles). The key role of PL in the development of prickles was further confirmed by CRISPR-Cas9 gene editing of PL in the prickly Australian wild species S. cleistogamum and S. prinophyllum, which recapitulated the phenotype. Our results indicate that PL may have had a major role in the evolution of an adaptive morphological novelty in the Leptostemonum Clade, as well as serving as a key genetic target during multiple instances of crop domestication.

### S.254.2 Exploring the evolutionary history of Carex (Cyperaceae) with new insights from geometric morphometrics

Ana Morales Alonso¹, Pedro Jiménez-Mejías², Carmen Benítez Benítez³, Andrew L. Hipp⁴, Sangtae Kim⁵, Modesto Luceño², José Ignacio Márquez-Corro⁶, Santiago Martín-Bravo², Eric H. Roalson⁷, Tamara Villaverde¹

1 Department of Biology and Geology, Physics and Inorganic Chemistry, Universidad Rey Juan Carlos, Madrid, Spain. 2 Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville, Spain. 3 Department of Plant Biology and Ecology, Universidad de Sevilla, Seville, Spain. 4 The Morton Arboretum, Lisle IL, USA. 5 Department of Biology, Sungshin University, Seoul, Korea. 6 Royal Botanic Gardens, Kew, Richmond, UK. 7 School of Biological Sciences, Washington State University, Pullman, USA.

Carex, with over 2000 species and a cosmopolitan distribution, is the second largest genus within monocots. The Global Carex Group, a research consortium established in 2013, has produced a series of publications addressing the systematics and evolution of this giant genus. As a result, a robust phylogenetic backbone at the subgeneric level and a sectional classification framework for Carex are now available. In this work, we have doubled previous genomic species sampling and obtained a well-supported Hyb-Seq phylogeny for all subgenera and represented groups, except for the subgenus Carex. For the first time, we applied geometric morphometrics to nutlet (achene) shape across all Carex, allowing the reconstruction of ancestral achene shape and its comparison among lineages.

This exploration will be informative about the anatomical diversification of the genus during its global expansion. Our work, by identifying synapomorphies of the organ likeliest to be preserved in the fossil record, will also help in the identification and subsequent incorporation of previously unassigned fossil records of Carex in divergence time estimation. Furthermore, we explore the potential correlation of achene shape and ecological requirements. Therefore, our results could potentially help to understand the possible triggers of radiation events and the factors influencing the expansion and settlement of the different Carex lineages.

### S.254.3 Genome dynamics across mega-diverse taxa: the role of changes in repetitive DNA on Begonia evolutionary radiations

Campos-Domínguez L.¹,²,³, Thea E. Kongsted¹,⁴, Turnbull L.¹,², Fan C.¹,², Miller C.¹,², Cure L.¹, Downie M.⁵, Qi Y.¹,², Tseng Y-H.⁶,⁷, Hu D.⁶,⁸, Chung K-F.⁶, Pellicer J.⁸,⁹, Bombarely A.¹⁰, Twyford A.D.¹, Kidner C.A.¹,²

1 School of Biological Sciences, University of Edinburgh, Edinburgh, UK. 2 Royal Botanic Garden Edinburgh, Edinburgh, UK. 3 Centre for Research in Agricultural Genomics, Bellaterra, Barcelona, Spain. 4 Gregor Mendel Institute of Molecular Plant Biology, Viena, Austria. 5 John Innes Centre, Norwich, UK. 6 Biodiversity Research Museum, Academia Sinica, Taipei, Taiwan. 7 National Chung Hsing University, Taichung City, Taiwan. 8 Royal Botanic Garden Kew, Richmond, London, UK. 9 Institut Botanic de Barcelona, Barcelona, Spain. 10 Instituto de Biología Molecular y Celular de Plantas, Valencia, Spain.

Understanding the drivers of species diversity and rapid radiations has always been a major goal in evolutionary biology research. Begonia is one of the most species-rich angiosperm genera with over 2000 pantropically distributed species currently identified. Recent work on Begonia provides a robust phylogenetic background for the analysis of evolutionary patterns across various radiations in the group, and suggests that speciation in Begonia is not only driven by adaptive processes, but rather by a "random walk". This group exhibits large variation in chromosome number and genome sizes across the genus, and previous genomic studies also confirm abundant and recent transposon activity in some Begonia species.
<figure><img src="image_587.png" /></figure>

We have analysed patterns in TE content and activi-
ty of all main radiations within Begoniaceae using the
five previously published *Begonia* genomes and sev-
en new genome assemblies. We show that *Begonia*
species show more complex, repetitive and dynamic
genomes overall than their close relative, the mono-
typic *Hillebrandia sandwichensis* and identify repeat
families recently expanded in species from two differ-
ent highly speciose South-East Asian sections and in
two large Neotropical radiations. We examined in de-
tail two of these parallel radiations represented by two
highly species-abundant sections, one in SE Asia and
the other in the Neotropics. Results show recent LTR
and wide satellite DNA expansions across very recent-
ly diverged species, in contrast with their species-poor,
closely related clades. The genomic analysis of *Bego-
nia heracleifolia* accessions showing variable genome
sizes revealed a markedly higher satellite repeat and
LTR-Gypsy content in the accessions with larger ge-
nome sizes, associated with the expansion of a few
abundant repeat lineages. We finally identify an asso-
ciation between changes in genomic repeat content
and genetic barriers to reproduction within this spe-
cies, directly linking expansions of repetitive DNA to the
process of genetic isolation and speciation.

S.254.4 Adaptive evolution of stomatal cluster and hypodermis in Asian Begonia

Hong-Wun Chen¹, Yu-Hsin Tseng², Shih-
Hui Liu³, Li-Wei Tsai¹, Ai-Qun Hu⁴, Kuo-Fang
Chung¹

1 Biodiversity Research Center, Academia Sinica, Taipei, Taiwan. 2 Department of Life Sciences, Taichung, Taiwan. 3 Department of Biological Sciences, Kaohsiung, Taiwan. 4 Singapore Botanic Gardens, Singapore.

With more than 2,000 species exhibiting striking mor-
phological variation, the mega-diverse genus Begon-
nia has emerged as a fascinating system for studying
plant speciation. Many explanations, such as genome
size variation, polyploidization, hybridization, and geo-
graphical isolation, have been proposed as the poten-
tial drivers for its high species richness. However, few
studies have studied the role of phenotypic variation
has played in facilitating ecological adaptation and
triggering speciation. One unique morphological ana-
tomic feature in some Begonia species is the presence
of stomatal cluster and hypodermis that are beneficial

for growing in arid habitats; however, the evolution-
ary importance of these anatomical traits has never
been investigated under a broad phylogenetic context.
Based on a highly resolved phylogenomic tree of Asian
*Begonia* reconstructed using target capture data, phy-
logenetic comparative analyses of three characters (i.e.,
singular vs. clustered stomata, absence vs. presence of
hypodermis, and epiphytic vs. lithophytic vs. terrestrial)
were conducted. Our study demonstrates strong and
significant phylogenetic signals in all three characters
and reveals high concordance between both leaf an-
atomical traits with habitat preference, implying a high
degree of phylogenetic niche conservatism in *Begonia*.
However, the transition from singular to clustered sto-
mata had occurred mainly in the common ancestors of
*B. sect.* *Baryandra* and *B. sect.* *Jackia* distributed mainly
in limestone karsts of the Philippines, Malaysia and In-
donesia, respectively. Considering the biogeographic
origin mainly mediated by long-distance dispersal in
*B. sect.* *Baryandra*, our findings suggest that, after the
common ancestors of *B. sect.* *Baryandra* dispersed to
the Philippines, the possession of stomatal cluster and
hypodermis could have facilitated the successful col-
onization to the limestone habitats throughout the ar-
chipelago. By integrating multiple data sets, our study
demonstrates how phenotypic variation and ecolog-
ical adaptation could have triggered an exceedingly
high speciation rate in the megadiverse *Begonia*.

S.254.5 Homoplasy in
the evolution of the New
World clade of Astragalus
(Fabaceae)

Joseph Charboneau¹

1 Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Missouri, USA.

With more than 3,000 recognized species, Astragalus L. (Fabaceae) is possibly the most species-rich genus of seed plants. With limited exceptions, the species recognized two decades ago have still been found to be part of one large Astragalus s.s. clade after subsequent phylogenies using small and large numbers of loci. These phylogenies have been relatively successful at identifying major clades within the genus especially for Old World species, where about 5/6 of the species richness of the genus is found. However, the phylogeny of the New World clade (informally called Neo-Astragalus) has proven more difficult to resolve. Neo-Astragalus has about 400 species in North America and 100+ species in South America that all
<figure><img src="image_588.png" /></figure>

have chromosome numbers in an aneuploid series (n = 11, 12, 13, 14, 15), in contrast to the euploid chromosome numbers predominant in the Old World (n = 8, 16). I speak about the origin of the aneuploid series and chromosome number evolution in Neo-Astragalus as well as the paralogy that hinders phylogenetic inference within the clade. In addition to the variable structure of Neo-Astragalus nuclear genomes, plas-

tid genomes in the clade have also undergone numerous rearrangements, some of which are shared by multiple species through homology and others shared through homoplasy. I also examine rates of homoplasy in morphological characters within Neo-Astragalus and Astragalus as a whole and discuss how this may have influenced the number of species assigned to the genus.

# S.255 SEEDS, SALINITY AND SURVIVAL: A FUNCTIONAL PERSPECTIVE

## S.255.1 Seed germination and seedling establishment strategies under salt stress

Hongxiang Zhang¹,²

1 Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China. 2 Royal Botanic Gardens Victoria, Melbourne, Australia.

Salinization is a serious agricultural and environmental problem worldwide that impacts crop production and natural ecosystems. Germination and seedling establishment is the prerequisite for species growing in saline environments. Thus, germination responses to salts have received considerable attention. The influences of salts on plant growth including germination include osmotic effects, ion effects and nutrient deficit. Therefore, germination strategy under salt stress should be considered based on these aspects of saline effects. We designed a series of experiments using grassland species and crops to study the related questions. We found that the osmotic effect was not the predominant effect under NaCl stress because the hydrotine model cannot predict germination of barley and grass species well. Then we proposed a salinity model which can better fit germination of these species under NaCl stress. The ion effect was adverse to germination only at high salinity, with sodium as an osmotic regulator to promote germination percentage and speed of barley at low and intermediate salinity. An experiment testing germination tolerance of 12 halophytes to salt type NaCl, Na₂SO₄ and NaHCO₃ showed species-specific responses to different salts and they were either salt tolerators (high germination at high salinity) or avoiders (high recovery germination when salinity alleviated). Bigger seeds had higher salt tolerant capability at high salinity. Further analysis with mixed salts revealed that the most closely related salt parameters with germination and

seedling growth was Na⁺ concentration, not pH. Diluted salt solutions should be considered to conduct recovery germination experiments, rather than distilled water based on our study. We found that proper N application may aid seedling establishment of grass species in saline soils, which denoted nutrient deficit effect of salts. These results help to understand plant adaptation in saline environments and provide important information for salt tolerant species/crops breeding.

## S.255.2 Variability in seed salinity tolerance in an island coastal community

Dustin Wolkis¹,², Seana Walsh¹,², Raffaela Abbriano¹,², Kasey Barton³

1 Department of Science and Conservation, National Tropical Botanical Garden, Kalāheo, HI, USA. 2 Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark. 3 School of Life Sciences, University of Hawai'i at Mānoa, Honolulu, HI, USA.

Many coastal plant species have adaptations that enable them to exist in higher saline conditions. However, rising sea levels, increased frequency and intensity of storm surges, and increased drought due to climate change are anticipated to increase the level of salinity to which coastal plants are exposed. Although some species may be able to tolerate these changes, salinity tolerance is highly variable across species and ontogenetic stage. Coastal ecosystems are critical for the welfare Hawai'i's residents, providing sustenance, stabilizing shorelines, and promoting economic and cultural well-being. Understanding how increased salinity will affect Hawaiian coastal plants is important to effectively manage and conserve these critical ecosystems. To improve our understanding of coastal
<figure><img src="image_589.png" /></figure>

plant species tolerance to projected increases in salinity exposure at the early ontogenetic stage of seed germination, we tested the effect of salinity (0, 10, 20, and 35 ppt total salinity of unfiltered/untreated seawater), then tested for resilience by rinsing seeds and sowing with freshwater. We included 17 native and 3 non-native species in our study. Although salinity tolerance varied considerably among species, salinity exposure generally reduced and delayed germination. The greatest effects were detected at higher salinity levels. Recovery germination overall was higher for seeds that had been exposed to higher salinity. None of the factors we explored emerged as predictors of salinity tolerance except seed mass, which tended to enhance germination at higher salinity. Species responses to salinity exposure indicate high vulnerability of coastal systems to increased salinity stress, and variability among species could lead to shifts in community assembly and composition under sea level rise. These results can help guide coastal ecosystem conservation and restoration management decisions in the face of climate change.

## S.255.3 Effect of Ibuprofen on the germination niche of halophyte species

Silvia Del Vecchio¹,², Marco Picone², Samira Gurbanli², Anna Volpi², Gabriella Buffa²

1 Università Degli Studi Roma Tre, Roma, Italia. 2 Università Ca' Foscari, Venezia Mestre, Italia.

Salt marshes are habitats of high ecological value and conservation concern worldwide. Recently, pharmaceutical pollution has become a further human-induced risk for these already-threatened environments. While the effects of pharmaceutical pollution were investigated on some fishes and invertebrates, they are largely unexplored for wild plants. This research investigated the effect of ibuprofen, one of the most commonly detected pharmaceuticals in surface waters, on seed germination of salt marshes plants. Adverse effects of this emergent contaminant can affect species population dynamics and, consequently, the integrity of salt marsh plant communities. We explored the germination requirements of *Juncus acutus*, *Limonium vulgare*, *Sarcocornia fruticosa*, *Tripolium panonicum*. Then, seeds of the best germinating species (*Juncus acutus* and *Limonium vulgare*) were exposed to increasing concentrations of ibuprofen (0, 2, 20, 200, and 2000 µgL⁻¹), both alone and under saline conditions (NaCl 513 mM). Recovery tests were performed to inves-

tigate seeds' ability to recover after salinity and Ibuprofen stress. In *J. acutus*, ibuprofen slightly decreased the germination percentage and increased the standard deviation around the mean values. Ibuprofen also increased the germination time and synchrony, although not significantly. *L. vulgare* showed a less linear trend and non-significant effects. Recovery tests showed that, although with fluctuating patterns, seeds of both species can recover from salinity, also when exposed in combination with Ibuprofen. This research for the first time empirically tested the effect of ibuprofen on the germination of wild species. Furthermore, it provides relevant insight to understand plant dynamics and their responses to emerging human-induced threats, such as pharmaceutical contamination.

## S.255.4 Saline Challenges: A Hygrotime Modeling Perspective on Germination Patterns in Mangrove Species under Differing Sodium Chloride Co

Malaka M. Wijayasinghe¹, Gehan Jayasuriya², Jeffrey L. Walck³

1 Department of Biological Sciences, Rajarata University of Sri Lanka, Mihintale, Sri Lanka. 2 Department of Botany, University of Peradeniya, Peradeniya, Sri Lanka. 3 Department of Biology, Middle Tennessee State University, Murfreesboro, TN, USA.

The study focused on investigating the impact of salinity on the germination of selected mangrove species; Aegiceras corniculatum, Acanthus ilicifolius, Pemphis acidula, Sonneratia caseolaris, and Allophylus cobbe, emphasizing the critical adaptations these plants undergo during germination to thrive in the challenging interface of salt and freshwater. The study explored the relationship between water potential in the growth medium and the germination rate by applying a hygrotime model. Seed germination was studied under various temperatures (15, 25, and 35 °C) and varying sodium chloride concentrations. The germination patterns of different mangrove species were analyzed, with a specific examination of whether these patterns align with the hygrotime model. Effects of salinity on cotyledon emergence were also evaluated for A. corniculatum. Temperature was identified as a critical factor affecting seed germination, particularly of S. caseolaris and P. acidula. Moreover, an interaction effect of temperature and medium osmotic potential
<figure><img src="image_590.png" /></figure>

was evident on seed germination. The research un-
veils distinct salinity tolerance levels among the tested
species, with A. corniculatum (a viviparous species)
exhibiting the highest tolerance, followed by S. case-
olaris, A. ilicifolius, P. acidula, and A. cobbe. A. cornicu-
latum, showed a delay in cotyledon emergence from
radicle emergence, showing epicotyl dormancy and
significantly fewer days to emerge cotyledon in higher
osmotic potentials when compared to lower osmotic
potentials. A. ilicifolius was the only species conform-
ing to the hydروtime model, with a determined thresh-
old water potential of ~1.8 MPa. Overall, the findings
revealed that the studied mangrove species exhibit
facultative halophytic behavior, capable of germinat-
ing across a wide range of saline environments. Sa-
linity can influence the duration of epicotyl dormancy
of A. corniculatum. While the application of a hydro-
time model was limited for mangroves due to devia-
tions from model criteria, the research enhances our
understanding of the intricate adaptations enabling
mangroves to thrive in extreme conditions.

S.255.5 Are there different germination patterns along the saline gradient in the co-occurrent halophytes in Mediterranean saltmarshes?

Joaquín Moreno¹, Alejandro Terrones²,
Ana Juan³

1. Miguel Hernández University of Elche, Elche, Spain.

2. Arid Zones Experimental Station (CSIC), Almería, Spain. 3. University of Alicante, Alicante, Spain.

Soil salinity is one of the most relevant drivers lead-
ing to plant zonation in Mediterranean saltmarshes,
where germination is a critical stage in the life cycle
of many halophytes. The study of how salinity allows
the germination and establishment of halophytes in
saline environments is a relevant first step to disentan-
gle the assembly processes in theses habitats, where
sympatric species occupate separate ecological
niches as a result of adaptive differentiation along the
salinity gradient. In this framework, the main goal of
this study is to assess if the co-occuring halophytes in
Mediterranean saltmarshes show different germina-
tion patterns along the salinity gradient. Experiments
were conducted considering the seeds of perennial
co-occuring species in Mediterranean saltmarsh-
es (Arthrocaulon macrostachyum, Salicornia fruti-

cosa, four sympatric *Limonium* species -*L. caesium*,
*L. cossonianum*, *L. delicatulum*, and *L. supinum* - and
*Lygeum spartum*) and the whole salinity gradient of
these habitats (0-6% NaCl). Our results suggest that
the successful establishment of halophytes depends
on the germination strategy which implies a rapid
germination velocity when the soil salinity decreases,
shaping the plant assembly within the saline habitat.
According to the obtained results, two different ger-
mination strategies have been defined which favour
the adaptation of different halophytes species under
favorable conditions. Certain species can germinate
along a wide salinity range (e.g., *S. fruticosa*, *L. cosso-
nianum*), whereas others are characterised by high
germination at low-medium salinities and a reduced
germination after high salinity exposure (e.g., *A. mac-
rostachyum*). These findings provide evidence to shed
light on the local assembly processes of halophytic
communities and its particular zonation.

S.255.6 Seed germination responses of annual back dune species to current and future climatic scenarios

Diana María Cruz Tejada¹, Clara Espinosa del Alba², Alessio Mo¹, Alice Fuggirai¹, Stefania Bottega¹, Eduardo Fernández Pascual², Angelino Carta¹

1 University of Pisa, Pisa, Italy. 2 IMIB Biodiversity Research Institute (University of Oviedo CSIC Principality of Asturias), Mieres, Spain.

Plant species living in coastal sand dunes face surviv-
al challenges from harsh environmental conditions like
high soil temperature and low water availability that
climate changes could exacerbate. The regeneration
of annual plant species depends on seeds; thus they
may be particularly vulnerable to climate-induced
environmental changes. We studied seed responses
of annual dune species to environmental cues in the
laboratory, with the aim of identifying the thermal and
water potential germination limits, as these could be
critical to forecast the germination risk. We sampled
characteristic annual species in Mediterranean back
dune grasslands: *Festuca fasciculata* (Poaceae), *Mar-
cus-kochia ramosissima* (Brassicaceae) and *Silene
canescens* (Caryophyllaceae). Fresh and after-ripened
seeds were exposed to different temperature and light
regimes. To explore water stress responses, seeds were
exposed to different water potential levels. After-rip-
<figure><img src="image_591.png" /></figure>

ening overcame dormancy allowing for germination responses at most temperatures and light conditions in *F. fasciculata* and *S. canescens*. *M. ramossima* had very low germination under all treatments except when exposed to GA3, thus this species probably exhibits deeper dormancy compared to the other two annuals. While *F. fasciculata* exhibited broader temperature and water potential germination niches (Psib50 = -0.83) compared to *S. canescens* (Psib50 = -0.24), the former species exhibited a thermal germination risk compared to the latter, which did not exhibit a risk.

Whilst light positively affected seed germination under no water stress, a negative effect was detected when seeds were exposed to water stress, indicating photoinhibition of seed germination under these conditions for all species. In conclusion, we found common responses among phylogenetically distant species (*F. fasciculata* and *S. canescens*) concerning the environmental cues examined. In particular, seeds can integrate water and light signals from their environment to modulate their germination responses to avoid the risk of seedling mortality that may occur in water stress scenarios.

# S.257 PLANT AWARENESS DISPARITY RESEARCH (PAD) AND CHALLENGES IN SCHOOL EDUCATION

## S.257.1 Assessing Plant Awareness - a tool for science and school

Benno Dünser¹, Andrea Möller¹, Peter Pany¹,²

1 University of Vienna, Vienna, Austria. 2 University College of Teacher Education Vienna, Vienna, Austria.

Since the early 20th century, biologists have bemoaned the lack of interest in plants and their neglect in education. Wandersee and Schussler (2001) defined this phenomenon as 'plant blindness' and challenged educational practitioners and researchers to investigate the causes and reform plant pedagogy. The next step in development was to redefine the condition as 'plant awareness disparity' to address the ableist connotations of the original term and to examine its components through the lens of the new definition. Following this line of thought, plant awareness, a novel perspective in contrast to deficit-oriented studies, encompasses visual perception, knowledge of and attitudes towards plants. Perceptual attention involves focusing mental resources on plants compared to other environmental elements. Attitude, a stable evaluation of a phenomenon, includes components such as perceived importance, appreciation, and preference for plants. Focused attention, positive affect and motivation contribute to an individual's interest in plants, whereas negative attitudes often arise from misconceptions about plant vitality. While various studies have examined these components individually, a comprehensive understanding of plant attitudes requires measurement tools that capture multiple dimensions and ensure internal consistency and structural validity. This oral presentation aims to promote a common understanding of plant awareness by exploring its conceptualisation and measurement methodology. The measurement tool we have developed will be examined in detail, as it is the first tool to go beyond self-report items. This includes an exploration of its development, overarching objectives, and the results of an expert-led validation of the Delphi technique. The in-depth examination of this measurement tool provides valuable insights into the complexities of plant awareness and highlights the evolving landscape of research in this area.

References: Wandersee JH, Schussler EE (2001). Towards a theory of plant blindness. Plant Science Bulletin 47, 2-9.

## S.257.2 Plant awareness in Spanish formal education: an analysis of new curricula and innovative experiences at initial teacher training

Marcia Eugenio-Gozalbo¹

1 Faculty of Education of Soria, University of Valladolid, Spain.

Plants constitute a highly diverse taxonomic group with fundamental ecological functions, which is currently undergoing a dramatic biodiversity loss. It is thus essential to promote their knowledge and appreciation
<figure><img src="image_592.png" /></figure>

through formal education, particularly during edu-
cational stages that are compulsory for all citizens. In
Spain, plants are studied along primary (6-12 years)
and compulsory secondary education (12-16 years). An
analysis of the new competence-based Spanish cur-
ricula (2022) was conducted by identifying all plant-re-
lated text fragments and classifying them into a system
of categories; the results will be presented and dis-
cussed to highlight both the strengths and weaknesses
of the new curricula regarding plant contents teach-
ing. Furthermore, and basing on the fundamental role
that teachers play for the introduction of new perspec-
tives in societies, two educational experiences aiming
to promote plant awareness in Spanish pre-service
teachers will be presented. The first one had two fun-
damental pillars: (1) the use of an organic garden as a
real-world context where students could establish di-
rect interactions with alive plants and develop attach-
ment to them, besides learning about plants that are
useful (thus facilitating authentic learning: linking new
knowledge to prior knowledge and noticing the rele-
vance and applications of their learning); (2) the use of
a teaching-learning strategy largely based on draw-
ing to promote observation, and including a seminar
on botanical illustration, drawing sketches from nature,
or designing mind maps. The didactic sequence in-
cluded other science activities and contents, with the
overall objective of integrating plant-related contents
and promoting plant awareness. The second one con-
stituted a refinement of that first experience, in which
some new and relevant elements were included, such
as a test that was purposely designed to assess stu-
dents' perception of plants both at the small and medi-
um-scales, as a measure of plant awareness. Results of
both experiences will be also presented and discussed.

S.257.3 Reverting plant
blindness: challenging civic
epistemologies through
education

Francisco Javier Navarro Prieto¹

1 Department of Philosophy, Autonomous University of Madrid, Madrid, Spain.

In the realm of plant sciences, both classical and
contemporary experiments have unveiled a level of
complexity in plant behavior surpassing conventional
perceptions held by the general public. Beyond their
fundamental ecological roles, plants exhibit intricate
behaviors akin to those observed in higher animals.
Positioned as scholars within the academic sphere, we

bear the responsibility of disseminating this knowledge
widely throughout society. This dissemination contrib-
utes significantly to the evolution of our shared "civic
epistemologies"—the processes through which knowl-
edge is cultivated and authenticated within a given
society, ultimately influencing public engagement and
decision-making. This oral presentation, framed under
the overarching theme of "Plants and Society," show-
cases recent educational initiatives that effectively
mitigate students' cultural "blindness" towards plants.
Commencing with an exploration of its historical con-
text, I introduce the concept of plant blindness—a term
coined in 1999 by botanists and educators James
Wandersee and Elizabeth Schussler. Subsequently,
an examination of "civic epistemologies" in the con-
text of plants will ensue, drawing insights from the
scholarly contributions of Sheila Jasanoff. The pre-
sentation will proceed to scrutinize three experiments
in higher education (Brenner, 2017; Bonser et al., 2013;
Nyberg y Sanders, 2013). Leveraging common tech-
nologies such as smartphones, these experiments
have demonstrated efficacy in heightening students'
awareness of plant behavior and ecological signifi-
cance. Following this, I contemplate the implications of
these experiments in challenging preconceived civic
epistemologies. Additionally, a conclusive sociological
study by Katherine Mach and colleagues (Mach et al.,
2020) will be presented to underscore the imperative
for a collective "coproduction" of knowledge across
diverse educational levels, ensuring heightened appli-
cability. Confronting the urgent challenges posed by
climate change necessitates an imperious call for so-
cieties to cultivate a more widespread dissemination
of plant-related knowledge within the public domain.

S.257.4 Revisiting the term
'plant blindness' with
community INCLUSION
AND GROUND-SOURCED
ALTERNATIVES

Renee M. Clary¹, Melanie Link-Perez²

1 Department of Geosciences, Mississippi State University, Mississippi State, USA. 15 Degree Laboratory 2 University of Tampa, Florida, USA.

When first identified in 1998, the construct of ‘Plant Blind-
ness’ captured public attention and summarized bota-
nists’ frustration with people’s inattention to plants. The
term grew in popularity over two decades and contin-
ues to be regularly invoked outside the United States,
with visual cognition explanations as the root cause for
the observed plant perception biases. With increasing awareness of the need for respectful communication for supportive and inclusive societies, researchers appropriately revisited the concept and recommended a new title of 'Plant Awareness Disparity.' Their goal of moving away from ableist language to describe this cognitive inattention toward plants is noble and forces reexamination of the language we use. While we applaud efforts to encapsulate public botanical inattention through considerate terminology, we propose that the journey to rename 'Plant Blindness' has not reached its natural community-based conclusion. We suggest that inclusive nomenclature for the community must arise from the community. We present our current research-based efforts to identify a ground-sourced alternative to 'Plant Blindness,' through which we invite participation of diverse voices to identify a ground-sourced alternative.

**S.257.5 Plant awareness in children's picture books**

Verity Jones¹

¹ University of the West of England, Bristol, UK.

In this contribution I theorise the importance of children's picture books as spaces for interaction and awareness with plants. I reflect on the new and more traditional genres within children's literature and how plants have been used (and abused) within them before critically reviewing a selection of popular children's fiction found in the five most popular supermarkets in England. One in five children's books in the UK are purchased at supermarkets and the selection of books in this study includes some of the most well-known and current popular titles. Following content analysis of a sample of these books (for audiences of ca. 5-10 years old) I highlight how plants are being represented in different ways, who (if anyone) is seen as responsible for these plants, what the impact of the plants are to the story, and how accurately they are represented (both through text and illustration). I then consider the potential impacts these representations may be having on young audiences and the challenges children's and illustrators are faced with. Final comments will suggest ways in which teachers and teacher trainers might choose and use books in order to support young people navigate plant awareness.

**S.258 PHYLOGENOMICS AND ADAPTIVE EVOLUTION OF THE WOODY PLANT GENUS RHODODENDRON**

**S.258.1 Pervasive hybridization during evolutionary radiation of Rhododendron subgenus Hymenanthes in mountains of southwest China**

Jianquan Liu¹,², Richard Milne³, Quanjun Hu², Yazheng Ma², Xingxing Mao², Ji Wang²

1 College of Ecology, Lanzhou University, Lanzhou, China. 2 College of Life Science, Sichuan University, Chengdu, China. 3 Institute of Molecular Plant Sciences, The University of Edinburgh, Edinburgh, UK.

Radiations are especially important for generating species biodiversity in mountainous ecosystems. The contribution of hybridization to such radiations has rarely been examined. Here, we

use extensive genomic data to test whether hybridization was involved in evolutionary radiation within Rhododendron subgenus Hymenanthes, whose members show strong geographic isolation in the mountains of southwest China. We sequenced genomes for 143 species of this subgenus and 93 species of four other subgenera and found that Hymenanthes was monophyletic and radiated during the late Oligocene to middle Miocene. Widespread hybridization events were inferred within and between the identified clades and subclades. This suggests that hybridization occurred both early and late during diversification of subgenus Hymenanthes, although the extent to which hybridization, speciation through mixing-isolation-mixing or hybrid speciation, accelerated the diversification needs further exploration. Cycles of isolation and contact in such and other montane ecosystems may have together
<figure><img src="image_593.png" /></figure>

promoted species radiation through hybridiza-
tion between diverging populations and species.
Similar radiation processes may apply to other
montane floras in this region and elsewhere.

S.258.2 Genomic insights
into spatiotemporal
evolution and adaptive
evolution of the species-rich
cosmopolitan plant genus
Rhododendron

Xiao-Mei Xia¹

1 Institute of Botany, Chinese Academy of Sciences, Beijing, China

Evolutionary radiation is a widely recognized mode
of species diversification, but its underlying mech-
anisms have not been unambiguously resolved for
cosmopolitan plant genera. The factors that en-
able certain species-rich plant genera to adapt to
diverse environments and achieve global distribu-
tion are still not fully understood. *Rhododendron*,
as the largest genus of woody plants in the North-
ern Hemisphere, presents an exceptional system
for investigating the genomic mechanisms driving
evolutionary radiations and the capacity to adapt
to a wide range of habitats. Here, we reconstructed
the first completely resolved and dated phylogeny
of *Rhododendron* and found that most extant spe-
cies originated by evolutionary radiations when
the genus migrated southwards from circumbo-
real areas to tropical/subtropical mountains. We
also found rapid increases of both net diversifica-
tion rate and evolutionary rate of environmental
factors in the Miocene, indicating that ecological
factors have triggered the evolutionary radiations.
Furthermore, we have accomplished high-quality,
chromosomal-level genome assemblies of nine
species and revealed diverse adaptive strategies
employed by *Rhododendron*, particularly the ad-
aptation to alpine and subalpine habitats by ex-
pansion/contraction of gene families involved in
pathogen defense and oxidative phosphorylation,
genomic convergent evolution, gene copy num-
ber variation, and a high percentage of private
genes. The adaptation to high altitudes is further
supported by our population genomic analysis of
*R. nivale*, a species representing the highest altitu-
dinal distribution within the genus and based on
comprehensive range-wide sampling. Moreover,

using metabolomic, transcriptomic, and genomic
analyses, we have identified the genes involved in
the biosynthesis of anthocyanins and carotenoids.
This study provides a good example of integrat-
ing phylogenomic and ecological analyses in de-
ciphering the mechanisms of plant evolutionary
evolutions. It holds considerable significance in
enhancing our understanding of plant adaptive
evolution and offers valuable insights for improv-
ing flower colors in this important horticultural
plant genus.

S.258.3 Genomic adaptation and future responses of an alpine rhododendron species in the eastern Hengduan Mountains

Qin Li¹, Kaining Hu², Xiaojun Kou³, Richard
Ree⁴

1 School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China.

2 Department of Human Genetics, University of Chicago, Chicago, USA. 3 School of Life Sciences, Beijing Normal University, Beijing, Shanghai. 4 Department of Science and Education, Field Museum of Natural History, Chicago, USA.

High-altitude plant species have shown local
adaptations to specific environments, such as
low temperature, drought, ultraviolet radiation,
and short growing season. In the face of climate
change, alpine specialists are more likely to expe-
rience range contractions and evolutionary risks.
To quantify such adaptation as well as vulnerabil-
ity, we sampled 15 populations of an alpine Rho-
dodendron (R. intricatum) with a large elevational
range (3000 m - 4500 m) in the Mt. Gongga region
of the eastern Hengduan Mountains in southwest-
ern China. Using a whole-genome re-sequencing
dataset, we performed genotype-environment
association (GEA) and gene ontology (GO) en-
richment analyses to explore its adaptation sig-
nature along elevation. Using inferred outlier SNPs
(single nucleotide polymorphisms), we then mod-
eled genetic turnover in a multidimensional cli-
mate space and estimated genetic offsets under
climate change. The genomic data showed no
significant geographic structure, while GAE tests
revealed a large number of outlier SNPs associat-
ed with elevation. Among the inferred significant
SNPs, GO enrichment analysis revealed a strong
<figure><img src="image_594.png" /></figure>

functional tendency associated with reproductive processes such as pollination and signaling. The current genetic turnover shows strong signals along climatic variables related to precipitation seasonality and extremes, which is consistent with a northeast-southwest geographic separation of the population. Meanwhile, such turnover signals would lead to remarkable risks at high elevations with intense precipitation changes in the future. Together, we highlight the genomic mechanisms underlying local adaptation at high altitudes. More importantly, we show that predicting climate vulnerability from both evolutionary and ecological factors reveals population-level risks to climate change in a mountainous region.

### S.258.4 Exon and exon-flanking regions sequence assembly from deep genome skimming data for Rhododendron phylogenomics

Zhi-Qiong Mo¹,²,³, Chao-Nan Fu¹, Alex Twyford³, Pete M. Hollingsworth⁴, Jun-Bo Yang², De-Zhu Li²,⁶, Lian-Ming Gao¹,⁶

1 CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China. 2 Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China. 3 University of Chinese Academy of Sciences, Beijing, China. 4 Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh, UK 5. Royal Botanic Garden Edinburgh, Edinburgh, Scotland, UK. 6 Lijiang Forest Biodiversity National Observation and Research Station, Kunming Institute of Botany, Chinese Academy of Sciences, Lijiang, Yunnan, China.

Using the deep genome skimming (DGS) data to assembly target nuclear orthologous genes for phylogenomics has recently become attractive, but little practical exploration has been done for herbarium specimens. Sequences flanking target genes are useful for phylogenetic inference of shallow taxonomic levels, while it is underutilized in studies possibly due to its finite recovery. We evaluated the optimal sequencing depth and performance for recovering target nuclear gene from specimen accessions, by subsampling genome sequencing data (10x, 15x and 20x sequencing coverage) with Rhododendron as ex-

ample. To explore whether the sequence recovery of target exons and their flanking regions improved or not, we utilized exons only or allowed intron-containing sequences (supercontigs) as reference for read sorting in assembly process using HybPiper, respectively. Additionally, phylogenetic analyses were conducted to test the phylogenetic utilities of plastomes and the captured nuclear exons and their flanking sequences. Our results showed that DGS can be well applied for herbarium specimens to recover large number of nuclear genes, and the optimal sequencing depth for high-quality gene assembly from specimens was ~15x coverage. Further analyses suggested that the adoption of supercontigs as reference can capture more higher-integrity target exons and flanking regions, and can be used as an alternative to increasing sequencing depth to improve sequence recovery in the case of limited sequencing data. The high-integrity nuclear sequences recovered here and plastome sequences recovered robust phylogenetic relationships in *Rhododendron*. It is also noteworthy that the recovered non-targeted exon-flanking regions showed great promise for shallow-scale phylogenetic relationships. The exons and flanking regions captured by adding introns into references for assembly shed new light on resolving interspecies relationships by using DGS data which recover high-integrity target nuclear genes and their flanking regions for phylogenomics of an expanding sampling covering both the extant and the natural history collections.

### S.258.5 The migration history of Kamchatka rhododendron (*Therorhodion camtschaticum* s.l.) - twice towards eastern Beringia

Ickert-Bond, Stefanie M.¹, Polezhaeva, Maria A.², Oliver, Margaret G.³

1 UA Museum of the North Herbarium and Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA. 2 Institute of Plant and Animal Ecology, Ural Branch, Russian Academy of Science, Ekaterinburg, Russia. 3 University of Tennessee Herbarium, The University of Tennessee, Knoxville, TN, USA.

*Therorhodion* is a small genus including three species – *T. redowskianum* with an Asian-restricted range and two amphiberingian taxa *T. camtschaticum* and *T. glandulosum*. The Kamchatka rhododendron
<figure><img src="image_595.png" /></figure>

(Therorhodion camtschaticum s.l.) is a small cold-resistant arcto-alpine shrub species with a controversial intraspecific taxonomy and a wide distribution range covering northern Eurasia and North America within Beringia. Russian taxonomists recognize one species with two subspecies, whereas two distinct species are recognized in North America following a broader species concept. We set out to unravel the taxonomic relationships within Therorhodion and the likely dispersal route/s of T. camtschaticum and T. glandulosum. First, we look at the overall phylogeny and recover strong molecular support for Therorhodion as the sister clade to Rhododendron, and within Therorhodion three strongly supported monophyletic clades representing three species are inferred. Next, we assess the level and distribution of diversity in the two closely related amphiberingian species within the native species range. The degree of differentiation we found is consistent with the species rather than subspecies status of the taxa studied. Two genetic lineages reflect the migration pathways of species from western Beringia to eastern Beringia. A northern pathway for T. glandulosum from northern East Asia (Okhotsk seashore, the Kolyma region, Chukotka, central and northern Kamchatka) to the Seward Peninsula in northern Alaska. A southern pathway for T. camtschaticum from the southern part of western Beringia (the Sikhote-Alin ridge, Sakhalin Island, the Kuril Islands, and southern Kamchatka) to the Aleutian Islands and the seashore of southeast Alaska. We inferred a divergence of Therorhodion from Rhododendron in the late Paleocene with the Asian-restricted T. redowskianum diverging during the middle Miocene, supporting an Asian origin for the genus. Demographic analysis using nSSR data inferred a divergence time between T. camtschaticum and T. glandulosum in the Pleistocene at 1.52 Mya.

## S.258.6 Phylogenomic and morphological insights into ploidy and the radiation of Rhododendron subsect Lapponica in the Hengduan Mountains

Ryan S. Fuller¹,², Qin Li²,³, Andrew R. Hipp¹,⁴, Jian-Quan Liu⁵, Richard H. Ree¹,²

1 Committee on Evolutionary Biology, University of Chicago, Chicago, IL, USA. 2 Negaunee Integrative Research Center, Field Museum of Natural History, Chicago, IL, USA. 3 School of Ecological and Envi-

ronmental Sciences, East China Normal University, Shanghai, China. 4 Center for Tree Science, The Morton Arboretum, Lisle, IL, USA. 5 College of Life Sciences, Sichuan University, Chengdu, China.

Understanding the evolutionary history in the genus Rhododendron (Ericaceae) is a difficult but important enterprise. The genus is iconic, both in horticulture where their charismatic flowers and hardy growth habits are highly valued, and as a prominent element of the North Temperate flora. In addition, polyploidy is highly desirable in rhododendron breeding and occurs naturally among multiple groups within the genus. The alpine group, subsection Lapponica remains somewhat of a mystery to 'rhody' enthusiasts. While some of the species in the group display consistent morphological identity across their geographic range, many taxonomic characters hold little value for delimitation. Additionally, we have uncovered a pattern where polyploids are more frequent than previously thought. Here, we present DNA relationships among samples from China and botanical garden material that test hypotheses about species boundaries in Lapponica. In tandem, using morphological data from flowers and leaves, we compare phenotypes to one another in an effort to understand where variation is most informative for species identification. Finally, we combine the two approaches together to provide our first look at the complicated and beautiful evolutionary history of Rhododendron's 'Hardy Mountaineers.'
# S.259 USING PLANTS FOR RESTORATION, CONSERVATION AND MANAGEMENT OF FRESHWATER HABITATS

## S.259.1 Macrophyte-based solutions: Environmental drivers, potential and limitations of aquatic plants as key actors in ecosystem restoration

Rossano Bolpagni¹

1 Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy.

Freshwater biodiversity is collapsing globally. Urgent and effective actions are essential to address this crisis within-a-crisis. In Europe, for example, most up-to-date data show that climate change is a growing threat (1), mainly due to increased drought and decreased precipitation, while agricultural activities, land abandonment and urbanization (2) are the main pressures on habitats and species of conservation concern. Natural wetlands emerge as the best sites for preserving adequate levels of aquatic and riparian vegetation and associated biota; however, especially in the lowlands, pristine wetlands and aquatic ecosystems have almost completely disappeared. Therefore, actions are needed to maintain, on the one hand, and recreate, on the other hand, an extensive network of wetlands capable of preserving acceptable levels of aquatic/wetland vegetation diversity and functioning. Understanding the eco-functional responses of macrophytes to ecological/anthropogenic pressures and local effects of the climate crisis is, then, crucial to achieving this fundamental goal. Findings gathered over the past two decades on diverse and complex wetland systems located in overexploited Italian lowlands confirm the key contribution made by natural sites in maintaining vegetation diversity in highly compromised riverine settings. This also suggests a direct effect of interannual and seasonal dynamics of water-level changes on observed vegetation patterns. In addition, progressive loss of hydrological connectivity and herbivory have been shown to massively affect macrophyte establishment and

growth processes, especially in the very early stages of development and recovery of an impaired water-body. Building on this evidence and delving into major international experiences in wetland restoration and enhancement, the aim is to outline the potential and limits of using macrophytes as nature-based solutions.

## S.259.2 Big plans for small pools: a morphological typology for in situ conservation and management of the seasonal rock pools of Malta

Sandro Lanfranco¹

1 University of Malta, Msida, Malta.

The seasonal freshwater rockpools (SFRs) of Malta constitute an Annex I 'priority' habitat (3170*) and function as a network of ecological islands supporting phytocoenoses that differ from those of the surrounding habitat matrix. The plants in these biotopes range from obligate aquatic species to amphibious species, to terrestrial species tolerant of saturated soils. Management, conservation, and restoration of SFRs provides unique challenges as the occurrence of these species is influenced by the integrated effect of multiple factors including the depth of water and sediment. Relatively small changes, on a scale of 1 cm, in the topography of the pool basin can modify the hydroperiod characteristics of the affected segment of the pool, leading to replacement of a plant assemblage by another. This study therefore aimed to guide management initiatives by proposing a morphological typology of SFRs, based on a sample of 170 pools from 12 pool landscapes. A preliminary hierarchical cluster analysis optimised by k-means partitioning suggested four morphoclasses of pools, each with their own indicator species. Morphoclass I: deeper pools with a low surface area to volume ratio and a thick sediment layer; Morphoclass II: shallow pools with a low surface area to volume ratio and