Genetic Diversity and Differentiation of Northern Populations of Pedunculate Oak Based on Analysis of New SNP Markers

The gene pool of populations of pedunculate oak (Quercus robur L.) from the north of the Russian part of the range of the species was studied using a set of 94 SNP loci. They were developed using the new generation DNA sequencing technology (ddRAD). Similar levels of genetic diversity were found in isolated stands with a small number of trees (expected heterozygosity HE = 0.313 ± 0.011, observed heterozygosity HO = 0.334 ± 0.004, allelic diversity υa = 1.540 ± 0.021, coefficient of inbreeding FIS = –0.067) and in relatively large populations (HE = 0.306 ± 0.010, HO = 0.318 ± 0.012, υa = 1.530 ± 0.021, FIS = –0.039). Statistically significant levels of interpopulation differentiation and population fixation (delta_T = 0.0993; Gregorius genetic distances d0 = 0.104–0.144, FST = 0.0725) were detected. Bayesian cluster analysis allowed identifying genetically distinct genetic groups. The results obtained are discussed taking into account the history of the distribution of pedunculate oak in the north of its range.