GENETIC-VARIATION AND DIFFERENTIATION IN NATURAL-POPULATIONS OF THE COMMON PINE PINUS-SYLVESTRIS L

Genetic variation and differentiation for 12 gene-enzyme systems was examined electrophoretically in eight natural populations of the common pine from the southern Urals (Russia), eastern Germany, and Latvia. The observed and expected heterozygosity values, averaged over all loci, were 0.156 and 0.183, respectively. The proportion of polymorphic loci was 48.3% and 59.4%, according to the 95% and 99% criteria, respectively. The average number of alleles per locus was 2.18, or 1.96 according to the 1% criterion. Intrapopulation variation explained approximately 98% of the total genetic diversity, while interpopulation heterogeneity accounted only for 2%. Nei's genetic distances between the populations varied from 0.004 to 0.022, averaging 0.010. Cluster analysis did not show associations between the distribution of the populations on the dendrogram and their geographic location. These results confirm existing evidence on the high level of genetic variation and low differentiation, which is characteristic of most conifer species,with large population sizes and extensive ranges.