Allozymes Genetic Diversity of Quercus mongolica Fisch in China

INTRODUCTION Analysis of the amount and distribution of genetic variation within and among populations of a species can increase the understanding of the historical processes underlying the genetic diversity (Dumolin- Lapegue et al. 1997) and can also provide important basic information for breeding programmes and for the establishment of programmes to conserve genetic resources. Moreover, information on the genetic structure allows for a more representative sample of the species’ gene p…

Allozymes Genetic Diversity of Quercus mongolica Fisch in China

A gel electrophoresis method was used to study the genetic diversity of 8 Quercus mongolica populations throughout its range in China. Eleven of 21 loci from 13 enzymes assayed were polymorphic. Q. mongolica maintained low level of genetic variation compared with the average Quercus species. At the species level, the mean number of alleles per locus (A) was 1.905, the percentage of polymorphic loci (P) was 52.38%, the observed heterozygosity (Ho) was 0.092 and the expected heterozygosity (He) was 0.099. At the population level, the estimates were A =1.421, P =28.976%, Ho = 0.088, He =0.085. Genetic differentiation (Gst was high among populations, it was 0.107. According to the UPGMA cluster analysis based on the genetic distance, 4 populations located in northeast and 2 populations in southwest of the geographical distribution are classified into 2 subgroups, but there was no clear relationship between genetic distance and geographic distance among populations. The low level of genetic diversity of Q. mongolica might be related to the long-term exploitation as economic tree species in history are comparatively seriously disturbed and damaged by human beings, and most of the existing stands are secondary forests.