Genetic diversity and structure of blue pine (Pinus wallichiana Jackson) in Bhutan

Blue pine (Pinus wallichiana Jackson) is a member of subsection Strobi that is an important component of middle- and high-elevation Himalayan forests. Five natural populations of P. wallichiana in Bhutan were investigated by starch-gel electrophoresis in an effort to determine the extent and distribution of genetic diversity. The level of genetic diversity was relatively high (A = 1.8; P-95 = 54.0%; H-0 = 0.163; H-e = 0.168) and the degree of genetic differentiation (G(ST) = 0.027) was low compared with those of other pines. The mean value of unbiased genetic distance, as proposed by Nei [Nei, M., 1978. Estimation of average heterozygosity and genetic distance from a small number of individuals. Genetics 89, 583-590.] (D = 0.003), confirmed that there is a very low differentiation and a close genetic relationship in blue pine populations of Bhutan. The estimates of the number of migrants per generation (N-m) of Wright [Wright, S., 1951. The genetical structure of populations. Ann. Eugen. 15, 323-354.] and Slatkin [Slatkin, M., 1985. Rare alleles as indicators of gene flow. Evolution 39, 53-65.] were 8.87 and 9.01, respectively. Five natural blue pine populations in Bhutan seemed to be in equilibrium with the expectations of Hardy-Weinbeg. (C) 1998 Elsevier Science B.V.