In order to carry out activities aimed at conservation and rational use of forest resources; it is necessary to study the main forest-forming plant species in detail. Scots pine (Pinus sylvestris L., Pinaceae) is mainly found in the boreal forests of Eurasia and is not so often encountered in the east of the East European Plain. The aim of the study was to study the genetic diversity, structure and differentiation of Scots pine populations in the east of the East European Plain. We studied ten populations of P. sylvestris using the Inter Simple Sequence Repeats (ISSR)-based DNA polymorphism detection method. Natural populations are demonstrated by relatively high rates of genetic diversity (He = 0.167; ne = 1.279; I = 0.253). At the same time, there is a tendency for a decrease in the genetic diversity of the studied populations of P. sylvestris from west to east. Analysis of the genetic structure shows that the studied populations are highly differentiated (GST = 0.439), the intrapopulation component accounts for about 56% of the genetic diversity. Using various algorithms for determining the spatial genetic structure, it is found that the studied populations form two groups of populations in accordance with geographic location. With the help of a genetic originality coefficient, populations with specific and typical gene pools are identified. They are recommended as sources of genetic diversity and reserves for the conservation of genetic resources of the species.

Genetic diversity is important for the long-term survival of species and plays a critical role in their conservation. To manifest the adaptive potential, it is necessary to preserve the allelic diversity of populations, including both typical and region-specific alleles. Molecular genetic analysis of 22 populations of Scotch pine (Pinus sylvestris L.; Pinaceae) in 10 subjects of the Russian Federation in the East European Plain and the Middle Urals was carried out. Molecular genetic analysis of 22 populations of P. sylvestris revealed 182 polymorphic PCR fragments. The studied populations are characterized by a medium level of genetic diversity. A high subdivision coefficient (GST) of the studied populations was established; the intensity was 0.559. At the same time, the level of subdivision differed for different regions; for the populations from the Middle Urals, it was 15.5% (GST = 0.155), and for the populations from the East European Plain, it was 55.8% (GST = 0.558). The dendrogram of genetic similarity shows five clusters of the studied populations of P. sylvestris according to their geographical location. The populations from the East European Plain are mostly characterized by typicality, while the populations from the Middle Urals, on the contrary, are more specific in gene pools. The use of the coefficient of genetic originality to identify populations with typical and specific alleles allows for solving the problem of selecting populations for the conservation of forest genetic resources. The data obtained on genetic diversity, and the structure of populations growing in areas of active logging, are important for determining the geographical origin of plant samples, which is an integral part of the control of illegal logging.