Abstract: Genetic diversity and population differentiation of the endangered plant Cathaya argyrophylla Chun et Kuang were studied in three populations in Bamian Mountain using the method of horizontal starch gel electrophoresis. Allozyme data for 25 loci of 13 enzymes indicated low level of genetic variability in this region with P = 0.28, A = 1.36 and He = 0.100. In contrast, there existed high degree of population differentiation among the three populations with Gsr value as high as 0.26, which was very different from the published results of other coniferious species. The low intrapopulafioned variability and strong interpopulational heterogeneity of C. argyrophylla in Bamian Mountain could be the impacts from several factors including stochastic processes such as genetic drift, and restricted gene flow between populations.

Key words: Cathaya argyrophylla, Genetic diversity, Population differentiation