Genetic diversity and differentiation among populations of the pedunculate oak(Quercus robur)at the eastern margin of its range based on a new set of 95 SNP loci

The aim of this study is to determine the genetic variability and differentiation among populations of pedunculate oak(Quercus robur)at the eastern margin of the species distribution range.We applied new set of 95 geographically informative nuclear SNP(single nucleotide polymorphism)loci developed using Double Digest Restriction Site Associated DNA(ddRAD),a new generation DNA sequencing technology.The study area is located in the basins of the Volga River and its two main tributaries,Kama and Belaya.Despite the strong reduction and fragmentation of pedunculate oak forests over the last several centuries and comparatively small sizes of present stands,a relatively similar genetic diversity of seven populations was observed(on average,allelic diversity v_(a)=1.472-1.603,observed heterozygosity H_(O)=0.305-0.358,expected heterozygosity H_(E)=0.272-0.343).The genetic distances between populations vary between 0.102 and 0.170(on average,d_(0)=0.128).We have identified the absence of a spatial genetic structure and the existence of genetically peculiar populations in the territory studied.The genetic distances of Gregorius between populations vary between 0.102 and 0.170(on average,d_(0)=0.128).Genetic differentiation among populations was statistically significant with a mean of the fixation index FST of 0.075.Populations from the Privolzhye Upplands and from northern parts of the study area make the most contribution to overall inter-population differentiation(d_(0)=0.137).No significant differences exist among the samples at lowlands along the Volga river(d_(0)=0.110).It was concluded that the multiplicity and different ages of local populations and the complexity of migration routes of the pedunculate oak from Pleistocene refugia and secondary Holocene shelters can cause this phenomenon.

Dynamics of annual growth of Pinus sylvestris on industrial wastes of mining companies

The development of the mining industry has led to the appearance in many parts of the world of vast technogenic territories from which toxic heavy metals enter the environment and food chains.Physical,chemical,and biological methods of cleaning industrial land due to technological complexity and hi gh cost are relatively little used on a large scale.Natural forest overgrowth of mining sites and the removal of heavy metals by woody plants can be an effective form of recovery.Therefore,the study of this process is of significant scientific and practical interest.The analysis of the annual growth in height and width of the annual rings of the stem of Scots pine(Pinus sylvestris L.) in 2004-2019 was made on the territory of the Uchalinsky mining and processing plant(South Ural,Russia) contaminated with heavy metals.Relatively hi gh concentrations of copper and zinc were found in soils,roots,bark,young shoots,comparable to exceeding the maximum allowable concentrations.Despite the spatial uniformity of the heavy metal content in the stands,the tree samples significantly differed in terms of annual growth.Results suggest that the lack of nutrients and not stress from exposure to heavy metals is the main reason for relatively low growth rates on slopes of industrial wastes.It was confirmed by studying the annual growth in height of the undergrowth in habitats with different soil cover conservation.The data prove the relatively high potential of Scots pine for the natural recovery of industrial lands polluted with heavy metals by mining enterprises.