Genetic Structure and Differentiation of Relict Lime Populations Based on the Analysis of Variability of Nuclear Microsatellite Loci

The genetic diversity, structure, and differentiation of relict lime plantations in Krasnoyarsk krai (considered as a separate species Tilia nasczokinii Stepanov) were for the first time studied on the basis of the analysis of variability of 12 microsatellite markers of the nuclear genome. In addition, six T. cordata Mill. populations from the European and West Siberian parts of its range and the T. sibirica Bayer population from Kemerovo oblast were included in the study. It was found that lime plantations in the vicinity of Krasnoyarsk (Manskoye Zaymishche and Kashtak) have a similar genetic structure and are in a state close to equilibrium. The level of genetic variability of T. nasczokinii populations is comparable to the level of variability of the T. sibirica population, but was significantly lower than in T. cordata populations. Estimation of the degree of genetic differentiation of lime populations according to interpopulation paired Fst values and Nei’s genetic distances (DN72) detected significant differences of the T. nasczokinii populations from the T. cordata and T. sibirica populations. The analysis of genetic differentiation (by the PCoA method) of paired Fst values and individual genetic distances (D), as well as clustering in STRUCTURE, demonstrated the separation of the studied populations into three groups according to their species affiliation. Moreover, the T. nasczokinii populations are genetically removed from the T. sibirica population to a greater extent than from T. cordata populations.