plants Article Molecular Phylogeny and Phylogeography of Potentilla multifida L. agg. (Rosaceae) in Northern Eurasia with Special Focus on Two Rare and Critically Endangered Endemic Species, P. volgarica and P. eversmanniana Ivan A. Schanzer 1,* , Alina V. Fedorova 1, Olga V. Shelepova 1 and Guzyaliya F. Suleymanova 2,3 1 Tsitsin Main Botanical Garden of Russian Academy of Sciences, Botanicheskaya Str., 4, 127276 Moscow, Russia;
[email protected] (A.V.F.);
[email protected] (O.V.S.) 2 Khvalynsky National Park, Oktyabrskaya Str., 2B, 412787 Khvalynsk, Russia;
[email protected] 3 Saratov State University, Astrakhanskaya Str., 83, 410012 Saratov, Russia * Correspondence:
[email protected]; Tel.: +7-915-362-1911 Received: 5 November 2020; Accepted: 17 December 2020; Published: 18 December 2020 Abstract: The results of a molecular genetic study of Potentilla multifida agg. using two plastid markers (ndhC-trnV and psbA-trnH) and a nuclear ITS marker suggested that this group comprises a number of relatively young and incompletely differentiated species widely distributed in Northern Eurasia. The sequences were analyzed using tree-based (maximum likelihood) and network-based (statistical parsimony network) approaches. The plastid data suggested incomplete lineage sorting, characteristic of the group as a whole. The nuclear ITS results demonstrated quite a different pattern, with mostly conspecific accessions shaping monophyletic clades. The majority of the Potentilla sect. Multifidae species studied possess few, usually closely related plastid haplotypes, or are even monomorphic. In contrast, P. volgarica, a narrow endemic from the Volga River valley, presents plastid haplotypes belonging to two distantly related groups. Such a pattern of genetic diversity in P.