Genetic variability of Scots pine (<i>Pinus sylvestris</i> L.) plus trees in the Middle and Upper Volga Region based on polymorphism of nSSR markers

BACKGROUND: One of the key issues in the area of forest selection is how to mitigate the risks evolving changes in the genetic structure and loss of diversity of future artificial forests due to the use of plus trees for seed production. Therefore, there should be studies aiming at assessing the genetic variability of plus trees selected for phenotypic traits in natural populations. AIM: The aim of this study is to examine of variability and differentiation of Scots pine plus trees selected for phenotypic traits from the Chuvash Republic, the Republic of Tatarstan and the Republic of Mari El with the use of nSSR markers. MATERIALS AND METHODS: Using five microsatellite loci, the authors assessed 207 plus trees of Scots pine from the Chuvash Republic, the Republic of Tatarstan and the Republic of Mari El. RESULTS: The number of alleles differed from 33 to 37 for various groups of plus trees. Thus, plus trees from the Mar El Republic are specified by a reduced level of diversity (Na = 6.6; Ne = 3.5; Ho = 0.361; He= 0.687) as compared to trees from the Chuvash Republic (Na = 7.4; Ne = 4.8; Ho = 0.503; He= 0.778) and the Republic of Tatarstan (Na = 6.8; Ne = 4.4; Ho = 0.570; He = 0.739). The groups of plus trees are slightly differentiated, and the genetic subdivision index equaled to 0.023. The major part of the nSSR marker polymorphism is within the groups of plus trees (98.0 %). CONCLUSIONS: The plus trees under study differ in the level of genetic variability. Relatively low allelic diversity and a large deficit of heterozygote are typical for all groups. Thus, we may conclude that the plus trees are compatible with natural populations of Scots pine grown in the Middle and Upper Volga Region in terms of distribution of genetic variability and differentiation.