The sustainable use and conservation of forest resources must be carried out with a detailed study of the main forest-forming plant species. Coniferous forests form the basis of boreal forest ecosystems and are of great economic importance. Representatives of forest-forming boreal coniferous species are species of the genus Pinus, including Siberian pine (Pinus sibirica Du Tour) and Scots pine (Pinus sylvestris L.), which are valuable and widely used woody plant species. The purpose of this research was to conduct an extended study of genetic diversity, genetic structure, and differentiation of P. sibirica and P. sylvestris populations under the conditions of their habitat in the Middle and Northern Urals. We studied twelve populations of two Pinus species using the inter-simple sequence repeat (ISSR)-based DNA polymorphism detection PCR method. Populations are characterized by relatively high levels of genetic diversity (P. sylvestris: He = 0.163; ne = 1.270; I = 0.249; P. sibirica: He = 0.148; ne = 1.248; I = 0.225). Analysis of the intrapopulation genetic structure reveals that the studied populations are highly differentiated (P. sylvestris: GST = 0.362; P. sibirica: GST = 0.460). The interpopulation component comprised 36% and 46% of the total genetic diversity for P. sylvestris and P. sibirica, respectively. Using various algorithms to determine the spatial genetic structure, it was determined that P. sylvestris populations form two groups according to their location at a certain altitude above sea level. P. sibirica populations form two clusters, with an additional subdivision of the two populations into subclusters identified. The data obtained during the study may be useful for further research as well as for conservation management planning and related forestry practices aimed at preserving the genetic resources of valuable forest plant species.

Based on the analysis of the polymorphism of two types of microsatellite markers (ISSR and SSR), the state of gene pools of the fifteen of Siberian larch populations from three regions of the Urals: Northern, Middle and Southern was estimated. The parameters of genetic diversity were revealed, its structure was established at the intrapopulation level. To assess the uniqueness of the gene pool, we used the coefficient of genetic originality (KGO), the analysis of which revealed populations with typical and region-specific gene pools. It was established that the studied samples are generally characterized by a high level of genetic diversity. It was found that the gene pools of samples from the South Urals are characterized by the greatest specificity, the lowest values of KGO, i. e. more typical gene pools, are noted in the North Urals samples of L. sibirica, the average values of KGO are from the samples of the Middle Urals. Also, 3 unique alleles were found in the ZIL, BND, and KCH samples, in the rest, no unique markers were detected. For a comprehensive assessment of the state of the gene pools of populations, all established indicators of genetic diversity have been transferred to the scale for assessing the status of gene pools developed on the example of the studied L. sibirica populations. Based on data on genetic diversity obtained using two types of molecular markers, it was found that the gene pools of ten studied L. sibirica populations are in satisfactory condition, and five have signs of gene pool degradation. Based on the results of the study, recommendations are made on the conservation of L. sibirica genetic resources in the Urals.

Research on the state and dynamics of the gene pool (an important natural resource that determines the potential fitness of living organisms and, ultimately, their long-term survival) becomes an important problem in the context of increased anthropogenic environmental impact. They are especially important for key species of ecosystems of a global scale importance. Larix sibirica Ledeb., which spreads from the Western Siberia to the Russian North-West, is one of such forest tree species. We identified patterns of genetic structure of populations on the example of the species’ Western race on the Middle and Northern Urals. The analysis of nucleotide polymorphism of genes of ABA-inducible protein, MADS-box-transcription factor and of 4-kumarat: CoA ligase (a part of the gene) was used as a method. Evidences were obtained that a part of the populations previously formed a single large population. At the same time, populations with different gene pools were found. As a result, differences between populations within the region were more pronounced (fixation index FST = -0.021 – 0.260, total haplotype diversity Hd = 0.636 – 0.911; nucleotide diversity π = 0.005 – 0.009; number of mutations θW = 0.005 – 0.012) than in other parts of the race. Causes of this phenomenon are discussed. It was concluded that the larch forests with a unique gene pool and/or high genetic diversity should be objects of population-oriented forestry and conservation.

The Ural Mountains and the West Eurasian Taiga forests are one of the most important centers of genetic diversity for Larix sibirica Ledeb. Forest fragmentation negatively impacts forest ecosystems, especially due to the impact of their intensive use on the effects of climate change. For the preservation and rational use of forest genetic resources, it is necessary to carefully investigate the genetic diversity of the main forest-forming plant species. The Larix genus species are among the most widespread woody plants in the world. The Siberian larch (Larix sibirica, Pinaceae) is found in the forest, forest-tundra, tundra (Southern part), and forest-steppe zones of the North, Northeast, and partly East of the European part of Russia and in Western and Eastern Siberia; in the Urals, the Siberian larch is distributed fragmentarily. In this study, eight pairs of simple sequence repeat (SSR) primers were used to analyse the genetic diversity and population structure of 15 Siberian larch populations in the Urals. Natural populations in the Urals exhibit indicators of genetic diversity comparable to those of Siberia populations (expected heterozygosity, He = 0.623; expected number of alleles, Ne = 4017; observed heterozygosity, Ho = 0.461). Genetic structure analysis revealed that the examined populations are relatively highly differentiated (Fst = 0.089). Using various algorithms for determining the spatial genetic structure, the examined populations formed three groups according to geographical location. The data obtained are required for the development of species conservation and restoration programs, which are especially important in the Middle Urals, which is the region with strong forest fragmentation.