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The genus Viola (Violaceae) is among the 40-50 largest genera among angiosperms, yet its 16 taxonomy has not been revised for nearly a century. In the most recent revision, by Wilhelm Becker 17 in 1925, the then known 400 species were distributed among 14 sections and numerous unranked 18 groups. Here we provide an updated, comprehensive classifica...
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The genus Viola (Violaceae) is among the 40–50 largest genera among angiosperms, yet its taxonomy has not been revised for nearly a century. In the most recent revision, by Wilhelm Becker in 1925, the then-known 400 species were distributed among 14 sections and numerous unranked groups. Here, we provide an updated, comprehensive classification of...
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In Europe, the V. epipsila—V. palustris group comprises V. epipsila Ledeb., V. palustris L., V. pubifolia (Kuta) G. H. Loos (=V. palustris subsp. pubifolia Kuta), interspecific hybrids, and putative introgressants. The genetic affinity of V. pubifolia to V. palustris, and their shared origin via hybridization followed by polyploidization, were confirmed using inter simple sequence repeat (ISSR) markers, restriction site-associated DNA sequencing (RAD-Seq), and a low-copy nuclear gene, GPI, which encodes glucose-6-phosphate isomerase. The other taxa of subsect. Stolonosae were not identified as putative parents of V. pubifolia by GPI. Our analyses indicated that V. pubifolia can be included in the morphological and genetic variation of V. palustris. The ISSR, RAD-Seq, and genome size value separated well V. palustris from V. epipsila and hybrids. The results also reopen the discussion on intraspecific variation in the context of taxa ranks and species concepts. The reduced tolerance of V. epipsila in Europe to changing environmental conditions might result from low genetic differentiation and heterozygosity, as well as the increased number of interspecific hybrids (V. epipsila × V. palustris), and eventually can possibly lead to its extinction. The disappearance of populations/individuals of this species may indicate anthropogenic changes occurring in peatlands.
Recently, the chloroplast genome of Viola verecunda from a sample collected in Japan has been published. Although the name is often recognized as a taxonomic synonym of Viola arcuata, the genetic identity of the two species has never been compared intensively. We report the complete chloroplast genome sequence of V. arcuata, of which sample was collected from Seoul, Korea. The cp genome of V. arcuata (OM301625) has 157,870 bp in length and is composed of four regions: 86,366 bp of a large single-copy (LSC) region, 17,298 bp of a small single-copy (SSC) region, and 27,103 bp of a pair of inverted repeats (IRs). The complete genome contains 130 genes, including 84 protein-coding genes, eight rRNA genes, and 37 tRNA genes. When comparing chloroplast genomes between V. verecunda, and V. arcuata, 34 different loci were recognized: 12 SNPs and 22 indels. In the coding regions, there were two amino acid insertions (ndhI) caused by one base deletion, three synonymous substitutions (ndhF, ccsA, and ndhI), and six nonsynonymous substitutions (matK, rpoC2, ndhF, ycf1, and two rpl2s on each IR region). In non-coding regions, variants of 19 polyN sites, one microsatellite, two insertions, and two SNPs were recognized. Phylogenetic analysis confirms a sister or nearly identical relationship between two genomes. This study will provide the genetic basis for solving a taxonomic problem between V. arcuata and V. verecunda.
