Variability of allozyme locus and inbreeding level in the age groups of southern-taiga and forest-steppe pine populations of the Central Siberia

The results of the study of isozymes variability of Scots pine populations growing in the southern taiga and forest-steppe of Central Siberia are presented. For the analysis 16 polymorphic loci were used. Two age groups (adult trees and undergrowth) are compared for the main indicators of genetic variation. The greatest deficiency of heterozygotes and a statistically significant level of inbreeding was found in the progeny of a small isolated population most disturbed by cuttings from the vicinity of the city of Achinsk. This population was distinguished by the high genetic distance of Nei (1972) between compared generations of trees, comparable to the distances between geographically remote populations. In the majority of other population samples exposed to lower anthropogenic pressure, the average level of heterozygosity was noted, or the observed heterozygosity was higher than expected in two age groups of trees, and deviations from the equilibrium state were found for individual loci, which, as a rule, do not coincide in adult trees and sprouts. The results of the study show that the genetic structure of the populations of Scotch pine Pinus sylvestris L. is quite resistant to the average level of anthropogenic (recreational) load. But the greater negative effect of using forest is associated with an increased risk of loss of allelic diversity (in 3 populations from 8 to 10.0–14.5 %) and, accordingly, the adaptive genetic polymorphism of populations. The necessity of using more sensitive than allozyme markers of genetic polymorphism of species populations (DNA markers of the nuclear and, especially, of the cytoplasmic genomes) in order to detect more subtle disturbances and initial stages of negative processes for the resumption of the gene pool of the processes was noted