DOI: 10.5061/dryad.b8gtht7ds
title: Significance of fruit and seed morphology in current taxonomy of the genus Iberis L. (Brassicaceae) in Turkey

description: Fruit and seed morphology of 10 taxa belonging to the genus Iberis
 (Brassicaceae) in Turkey were investigated with stereo microscopy (SM) and
 scanning electron microscopy (SEM), in order to understand and check their
 diagnostic significance at generic and spesific level. Fruits and seeds of
 Iberis species were photographed and examined to evaluate different
 characteristics including fruit size, shape, color, indumentum, surface
 ornamentation, style length, sinus width, wing width, septum length, and
 also seed size, shape, color, surface ornamentation, cell types,
 anticlinal and periclinal cell wall features. In addition, cluster
 analysis and principal coordinates analysis (PCoA) were performed to
 reveal the similarities between the related taxa in terms of seed and
 fruit morphology. According to fruit morphology, Iberis taxa in Turkey are
 divided into three main groups particularly by fruit shapes, those are
 ovate, ovate-obovate and ovate-orbicular. In the present study SM
 photographs of both immature and mature fruits of relevant species were
 also provided for the first time. Style length, which is one of the most
 important features between some Iberis taxa was taken into consideration
 in the study. There are three types of seed shapes, those are
 inequilateral obovate, broadly obovate and inequilateral elliptic. The
 fruit size limits of I. simplex were also been expanded. The UPGMA tree
 topology of cluster analysis based on a total of 20 fruit and seed
 characters presents the current taxonomical classification of the taxa in
 Turkey, which is updated in this study. An identification key for the
 genus Iberis in Turkey was provided in the light of current data.
description: Plant
 specimens used for this study were collected from different regions of
 Turkey. The author carried out field studies in many parts of Turkey
 between 2017-2020; and also some collections of other researchers and some
 herbarium specimens were taken into consideration and listed in Table 1
 and Table 3. Relevant literature (Boissier 1867, Hedge 1965, Vural et al.
 2012, Oskay 2017, Yıldırımlı 2018) were used for the identification of
 <em>Iberis</em> taxa. <em>I. umbellata</em>, a
 cultivated species which was reported only from İstanbul, Turkey (Mutlu
 2012) had not been collected and/or evaluated. <em>I.
 attica</em> and <em>I. spruneri </em>are<em>
 </em>treated as two separate species instead of <em>I.
 carnosa</em>. The author
 studied and measured the material collected in the field listed in Table 1
 and Table 3 and the specimens are deposited in Hacettepe University
 Herbarium (HUB). These materials are studied together with type and
 representative material of collections of <em>Iberis</em> from
 24 different herbaria worldwide, BM, E, G, K, L, U, LD, LINN, P, WAG, W,
 WU, AEF, ANK, AIBU, DUOF, EGE, GAZI, HUB, ISTE, ISTF, ISTO, KNYA and MARE
 (acronyms according to Thiers 2021+). Morphological
 measurements were made using an ocular micrometer on stereoscopic
 binocular (Leica Zoom 2000), with the exception of the larger ones
 (&gt; 10 mm), which were taken using a standard ruler. For SM
 photographs of the fruits, two images were taken for each taxa,
 representing their immature and mature appearances. The fruit and seed
 samples that best reflect the characteristics of the related species among
 the populations were photographed. For SM photographs of the seeds, one
 image was taken for each taxa, representing their general appearance. SM
 photographs were taken by Dino-Lite and Dino-Eye, the versatile digital
 microscope using DinoCapture 2.0, version 1.5.40.A programme. In the light
 of new morphological data from recently collected specimens, a current
 identification key is prepared for the fruit and seed characters of the
 genus <em>Iberis</em> in Turkey.
 <strong>Scanning electron microscope (SEM)
 analysis</strong> For SEM
 analysis of the seeds, totally two images were taken for each taxa,
 representing the general appearance of the seeds of all collected
 <em>Iberis</em> taxa and the ornamentation of the testa
 surface. For SEM analysis of the fruits, one image was taken for each
 taxa, representing the surface ornamentations of the fruit. SEM studies
 were carried out in both in Hacettepe University Geological Engineering
 Department and in Hacettepe University Advanced Technologies Application
 and Research Center (HUNITEK). For SEM analysis, a Zeiss EVO 50 EP (Low
 Vacuum [~100 pa] VPSE) (in Geo. Eng. Dept) and a Tescan GAIA 3 (Low
 Vacuum, under 30kV and &lt; 25 nm resolution) (in HUNITEK) scanning
 electron microscopes were used. Samples for SEM were prepared by directly
 mounting fruits and seeds onto clean stubs. After coated with gold by
 using EMS250-333, micrographs of seeds were taken with SEM, connected to a
 Bruker-Axs Quantax X-Flash 3001 EDS. Taxa, whose fruits and seeds were
 photographed by scanning electron microscope, their voucher numbers and
 localities are listed in Table 1, in alphabetical order. 
 <strong>Multivariative morphometric analysis:
 </strong> To make measurements for the
 present study, 12 characters for fruit and 8 characters for seed of
 <em>Iberis</em> taxa were determined and listed. This dataset
 including both quantitative measurements and qualitative characteristics
 were also used for the multivariative morphometric<strong>
 </strong>analysis. Measurements were made on 10 individuals
 representing the species selected from different populations of the
 species for each species. For the species with a weak population, narrow
 distribution or few individuals, all available individuals were measured.
 Totally 298 individuals from 59 different <em>Iberis</em>
 populations from Turkey were studied (Table 3). PAST (PAleontological
 STatistics) ver. 4.03 programme was used for the analysis (2001). For the
 cluster analysis, totally 20 morphological characters  were used and
 examined. Each qualitative character examined in data set were defined and
 coded as binary or multiple characters to be converted to numerical data
 (Table 2). Quantitative characters (FL, FW, STL, SIW, WW, SPL, SL, SW)
 were measured for each individual, mean values and standard deviations
 were calculated for each voucher specimen, and a matrix data was generated
 (Table 5, Supporting data). Cluster analysis was carried out by SAHN
 (Sequential Agglomerative Hierarchical Nested Cluster Analysis) and UPGMA
 (Unweighted Pair Group Method with Arithmetic Average) method. Gower
 similarity index was used to examine both quantitative, binary and nominal
 data as multiple characters. Besides, relevant morphological characters
 were also coded in a matrix (Table 2, Table 5) used as input for the
 principal coordinates analysis (PCoA) which tries to represent
 (dis)similiarities between mixed variables (Gower 1971, Rohlf 1972,
 Hammer, et al. 2001).