Genetic variation, population structure, and differentiation in scots pine (Pinus sylvestris L.) from the northeast of the Russian plain as inferred from the molecular genetic analysis data

The DNA polymorphism in Pinus sylvestris L. from Severodvinsk, Upper Vetluga, and Vetluga–Vyatka populations, which were isolated earlier based on specific features of the geographic variation of allometric cone indices, was examined by the ISSR method. It was demonstrated that the Severodvinsk population of P. sylvestris differed from the chorologically adjacent Upper Vetluga population with respect to all of the examined genetic indices, and the Upper Vetluga population differed from the Vetluga–Vyatka population. It was suggested that the main the reason for the lack of statistically significant differences between Upper Vetluga and Vetluga–Vyatka samples of P. silvestris with respect to genetic variation indices (P95, HE, na, ne) may be their formation based on the gene pools of two glacial refugia. It was demonstrated that the proportion of the interpopulation component of total genetic diversity (GST), as calculated based on the ISSR marker polymorphism, reached a value of 0.488, which was an order of magnitude higher than the previous estimates obtained based on data from allozyme analysis. It was concluded that P. sylvestris cone allometric indices reflected the specificity of spatial population subdivision, like the genetic diversity and population genetic structure indices calculated based on ISSR-marker polymorphism. Population isolation and mapping based on two-step phenogenetic studies is suggested.