Introgressive hybridization is an important evolutionary process frequently contributing to diversification and speciation of angiosperms. Its extent in other groups of land plants has only rarely been studied, however. We therefore examined the levels of introgression in the genus Diphasiastrum, a taxonomically challenging group of Lycopodiophytes, using flow cytometry and numerical and geometric morphometric analyses. Patterns of morphological and cytological variation were evaluated in an extensive dataset of 561 individuals from 57 populations of six taxa from Central Europe, the region with the largest known taxonomic complexity. In addition, genome size values of 63 individuals from Northern Europe were acquired for comparative purposes. Within Central European populations, we detected a continuous pattern in both morphological variation and genome size (strongly correlated together) suggesting extensive levels of interspecific gene flow within this region, including several large hybrid swarm populations. The secondary character of habitats of Central European hybrid swarm populations suggests that man-made landscape changes might have enhanced unnatural contact of species, resulting in extensive hybridization within this area. On the contrary, a distinct pattern of genome size variation among individuals from other parts of Europe indicates that pure populations prevail outside Central Europe. All in all, introgressive hybridization among Diphasiastrum species in Central Europe represents a unique case of extensive interspecific gene flow among spore producing vascular plants that cause serious complications of taxa delimitation.

• MeSH
• biologická evoluce MeSH
• délka genomu * MeSH
• diploidie MeSH
• DNA rostlinná genetika   MeSH
• druhová specificita MeSH
• ekosystém MeSH
• genetická variace MeSH
• genetické markery MeSH
• genom rostlinný * MeSH
• hybridizace genetická * MeSH
• křížení genetické MeSH
• listy rostlin anatomie a histologie   MeSH
• plavuňovité anatomie a histologie   klasifikace   genetika   fyziologie   MeSH
• spory MeSH
• stonky rostlin anatomie a histologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Geografické názvy
• Evropa MeSH
• Názvy látek
• DNA rostlinná MeSH
• genetické markery MeSH