Mudrik O. Genetic structure dynamics of the natural populations of some family Pinaceae Lindl. species in Ukraine

The thesis is devoted to genetic dynamics investigations of Pinus sylvestris var. cretacea Kalenicz. еx Kom., P. sylvestris L., P. pallasiana D. Don and Picea abies (L.) Karst. natural populations in Ukraine using isozymes as a genetic markers. The maintenance of maternal trees allele diversity and the deficiency of heterozygous genotypes in the seed progenies of all investigated populations have been revealed. The adults samples of studied populations are in genotype equilibrium according Hardy-Weinberg low whereas the embryos samples are in genotype disequilibrium due to excess of homozygotes. Both decreasing of heterozygosity level and increasing of predominant alleles frequency with the age of the plants have been fixed in Pinus sylvestris var. cretacea population. It has been determined that relic P.sylvestris var. cretacea population growing on carbonate soils in Donetsk region and P.sylvestris population on carbonate soils of Cremenets holly region have similar genetic structure and genetic variation level. The absence of strict genetic differentiation of trees and their seed progenies along elevation gradient in mountainous P. pallasiana population has not been found. It has been determined that P.pallasiana seed productivity depends on trees heterozygosity and level of outcrossing. It has been investigated the temporal outcrossing dynamics in P.pallasiana and P.sylvestris var. cretacea populations. It has been determined the loci of P.sylvestris var. cretacea and P.pallasiana trees producing a big amount of heterozygous seeds. Key words: genetic structure, variation, differentiation, heterozygosity, heterogeneity, mating system, isozymes, population, seed progeny.