Format: ORAL

Natalia Tkach1, Martin Rser1, Tomasz Suchan2, Elzbieta Cieslak2, Peter Schnswetter3, Michal Ronikier2

1 Department of Geobotany and Botanical Garden, Institute of Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany 2 W. Szafer Institute of Botany, Polish Academy of Sciences, Krakow, Poland, 3 Department of Botany, University of Innsbruck, Innsbruck, Austria

The Carpathians and the Alps are the largest mountain ranges of the European Alpine System and important centers of endemism. Among the distinctive endemic species of this area is Saxifraga wahlenbergii, a Western Carpathians member of the speciose genus Saxifraga. It was frequently suggested a taxonomically isolated Tertiary paleopolyploid and paleoendemic. A recently described narrow endemic of the Eastern Alps, S. styriaca, was hypothesized to be closely related to S. wahlenbergii due to the presence of pelicular glandular hairs. Clarifying the origin and phylogenetic relationships of both species could provide valuable insights into evolutionary and biogeographical history of the Carpathian and Alpine floras. To this end, their nuclear and plastid DNA were analyzed using Sanger and NGS (MiSeq) in a broad taxonomic context. Different evolutionary courses were found: S. wahlenbergii has a complicated hybrid origin. The maternal parent is a part of a West Eurasian lineage consisting of high mountain taxa within subsect. Androsaceae and could be widespread S. androsacea itself. The paternal lineage belongs to the distantly related subsect. Tridactylites, which also includes S. adscendens, the presumed second parent of S. wahlenbergii. The NGS screening revealed presence of sequences from both lineages. The second species S. styriaca was clearly assigned to subsect. Androsaceae and is not the sister of the first species. The similarity of the glandular hairs of both taxa is thus based on parallelism, and both species are not an example of a close evolutionary connection between the Western Carpathian and the Eastern Alpine floras. Since the origin of the paternal S. adscendens-like ITS DNA is estimated to be ca. 3.0 Ma, S. wahlenbergii cannot be relict of the mid-Tertiary climate optimum. Its hybrid origin is much younger and most likely took place in the Pleistocene.