Genetic Structure of Shorea macrophylla in Sarawak, Malaysia

Abstract

The genetic structure of Shorea macrophylla in Sarawak was examined by using allozyme variation. Fifteen seedling families each originated from a single mother tree, henceforth called families, were selected at west and central Sarawak. Leaves were sampled from 30 seedlings per family, and were subjected to allozyme analysis. Percent of polymorphic loci was 43% and the mean heterozygosity (H_e) of the species was 0.209. The UPGMA cluster analysis conducted for the fifteen families extracted three genetic clusters, which were accordant with three geographic ranges, Kuching, Sri Aman, and Bintulu, respectively. G_ST for these three populations was estimated as 0.208, meaning 20.8% of total genetic diversity occurred in the variation among three populations. Thus the genetic structure of S. macrophylla was characterized by moderate genetic diversity within species and high genetic differentiation among local populations.