DOI: 10.5061/dryad.3j9kd51wf
title: Data from: <em>Veronica paczoskiana</em> is no more than a pine forest ecotype of <em>V. spicata</em> that evolved independently in forest-steppes of Ukraine and the Altai region

description: The Eurasian steppe area has been a dynamic vegetation type during the
 Pleistocene with its repeated cycles of forest advances and retreats. Such
 a scenario allows the evolution of ecotypes at the ecotone with the
 potential for parallel evolution in different parts of the distribution
 area. We test this hypothesis using the forest steppe/steppe herb Veronica
 spicata, based on results from genotyping-by-sequencing and pollen
 morphology. We provide evidence that the forest-living
 paczoskiana-morphotype evolved independently in Ukraine (the type locality
 in central Ukraine) and the Altay region, but potentially also elsewhere.
 Pollen morphology of 26 herbarium specimens was studied using both light
 microscopy and scanning electron microscopy. Pollen grains are
 3(4)-colpate and 3-colporate, suboblate to prolate (P/E = 0.82–1.75) in
 shape; small- and medium-sized. Pollen grains of forest ecotypes were
 usually smaller in size (mean 20.74 × 18.72 µm) than pollen of grassland
 V. spicata (mean 23.79 × 20.98 µm). Lack of an indumentum,
 reddish stem color, and smaller pollen seem to be parallel adaptations to
 the shadier and more acidic soil in these forests. The dynamic history of
 the forest-steppe zone in Eurasia during the Pleistocene provides a
 compelling scenario supporting the convergent evolution of this
 morphotype.
description: The Eurasian steppe area has been a dynamic vegetation type
 during the Pleistocene with its repeated cycles of forest advances and
 retreats. Such a scenario allows the evolution of ecotypes at the ecotone
 with the potential for parallel evolution in different parts of the
 distribution area. We test this hypothesis using the forest steppe/steppe
 herb <em>Veronica spicata</em>, based on results from
 genotyping-by-sequencing and pollen morphology. We provide evidence that
 the forest-living paczoskiana-morphotype evolved independently in Ukraine
 (the type locality in central Ukraine) and the Altai region, but
 potentially also elsewhere. Pollen morphology of 26 herbarium specimens
 was studied using both light microscopy and scanning electron microscopy.
 Pollen grains are 3(4)-colpate and 3-colporate, suboblate to prolate (P/E
 = 0.82–1.75) in shape; small- and medium-sized. Pollen grains of forest
 ecotypes were usually smaller in size (mean 20.74 × 18.72 µm) than pollen
 of grassland <em>V. spicata</em> (mean 23.79 × 20.98 µm). Lack
 of an indumentum, reddish stem color, lower specific leaf area, and
 smaller pollen seem to be parallel adaptations to the shadier and more
 acidic soil in these forests. The dynamic history of the forest-steppe
 zone in Eurasia during the Pleistocene provides a compelling scenario
 supporting the convergent evolution of this morphotype.
description: # Data from: *Veronica paczoskiana* is no more than a pine forest ecotype
 of *V. spicata* that evolved independently in forest-steppes of Ukraine
 and the Altai region
 [https://doi.org/10.5061/dryad.3j9kd51wf](https://doi.org/10.5061/dryad.3j9kd51wf) ## Dataset Summary This dataset supports the study *“Veronica paczoskiana is no more than a pine forest ecotype of V. spicata that evolved independently in forest-steppes of Ukraine and the Altai region”* (DOI link). It includes genomic and phylogenetic data used to assess the evolutionary status of *Veronica paczoskiana* within the *V. spicata* complex. **Description of Data and File Structure** * **map.txt** – Sample metadata and accession mapping * **Paczoskiana_Bayesean-Inferred.tre** – Bayesian phylogenetic tree * **Paczoskiana_MaximumLikelihood.tree** – Maximum likelihood phylogenetic tree * **Veronica_paczoskiana.nex** – Nexus file containing aligned loci for phylogenetic analysis The dataset comprises 38 accessions representing the morphological diversity of *V. spicata*, including outgroup taxa (*V. incana*, *V. pinnata*, *V. spuria*). Genomic DNA was extracted from dried material using the innuPREP Plant DNA Kit (Analytic Jena AG, Germany), and quality was assessed via gel electrophoresis and photometry (TECAN Infinite F200 Pro). Ploidy was determined for 22 accessions via flow cytometry (Meudt et al. 2015); data for 16 accessions were unavailable due to insufficient material or poor quality (CV &gt; 8 %). RAD-Seq libraries were prepared following Elshire et al. (2011) using the methylation-insensitive enzyme MSII, with protocol modifications from Siadjeu et al. (2018). Libraries were sequenced at LGC Genomics (Berlin, Germany). Reads were assembled using IPYRAD v.0.9.96, optimized for reference-free phylogenomic analysis. Key parameters included: * Phred score offset: 33 * Sequence similarity threshold: 85 % * Barcode mismatches: 0 * Adapter filtering: strict * Indel limit: 5 per locus * Minimum depth: 6× * Loci retained if present in ≥ 30 % of individuals ### Code/Software Used * **FastQC**, **MultiQC** – Raw data quality control * **IPYRAD v.0.9.96** – Locus assembly and filtering * **IQ-TREE v.2.3.6**, **jModelTest v.2**, **MrBayes v.3.2.2** – Phylogenetic inference