Pattern and magnitude of genetic diversity in Pinus gerardiana wall. Populations

Abstract

Twelve populations of Pinus gerardiana in North- west Himalayas of India were analysed for isozyme variation based on the seven enzyme systems. In isozyme analysis, of the 16 gene loci identified for the assayed seven enzyme, six loci under six enzyme systems were polymorphic. Only one enzyme system i.e. GDH does not show any polymorphic loci. The mean number of alleles per locus was 1.48 and mean expected heterozygosity was 15%. The gene pool allelic differentiation among the populations varied from 38.2% to 45. 2% whereas gene pool genotypic differentiation varied from 52% to 60%. For all possible pairs of populations Nei’s genetic distance values averaged 0.0021.The value of differentiation observed in the study could be attributed to the adaptive mechanism to the microenvironment shows high level of polymorphism.