ИСТИНА

The aims of the study are: 1) to characterize genetic (SSRs and cpDNA sequences) variation in Northern Eurasian populations of Lotus corniculatus complex, 2) to study gene flow between the cytotypes and 3) to obtain the first insights into the evolutionary history of L. corniculatus complex. Markers: SSR analysis (8 loci), trnL-F region of cpDNA. Methods: AMOVA, Structure, TCS. Material: SSR analysis: 47 populations sampled across a wide area in E. Europe, Caucasus, Siberia and Central Asia (425 individuals in total). TrnL-F sequences: 174 Lotus specimens, representing Lotus corniculatus complex (150 ind.) and outgroups. Results and conclusions. European populations of 2x L. tenuis and L. stepposus and 4x L. ucrainicus and L. corniculatus are generally characterized by higher genetic diversity and lower genetic isolation than populations of Euro-Asian (2x L. frondosus) and Asian (2x L. krylovii) species. Decrease of genetic variability in combination with increasing genetic isolation may be related to autogamy, which presumably plays significant role in the breeding system of the latter two species. Minimal genetic diversity was observed in L. krylovii populations from Tyva and Mongolia. Our data support rare introgression between two ploidy levels. Phylogeographical analysis of the section Lotus by trnL-F cpDNA marker revealed, that within the material studied, a haplotype of L. alpinus from Spain (the Iberian System) was the closest one to a hypothetical ancestral haplotype of the L. corniculatus complex. Derived haplotypes were spreading eastward, and two areas of diversification: in Central and Eastern Europe (of a higher diversity level) and in the Asian part of Northern Eurasia (of a lower diversity level) are known. Tetraploid species L. ucrainicus and L. corniculatus share haplotypes with European but not Asian diploid species.