八面山银杉林的遗传多样性和群体分化

采用水平淀粉凝胶电泳技术对分布于湖南八面山的濒危植物银杉(cathaya argyrophylla Chun etKuang)的遗传多样性和群体分化进行了初步研究。对13个酶系统25个等位酶位点的检测表明,该地区的银杉林群体遗传变异水平很低,多态位点比率 P=0.28,等位基因平均数 A=1.36,平均期望杂合度He=0.100;但3个小群体间存在着明显的遗传分化,基因分化系数高达G_ST=0.26,明显不同于其它裸子植物的报道。八面山银杉林低水平的遗传变异和明显的群体分化,一方面反映了银杉的古老性和残遗性,另一方面也说明在银杉的进化过程中可能发生了严重的遗传漂变,而且群体之间的基因流明显受阻。

GENETIC DIVERSITY AND POPULATION DIFFERENTIATION OF CATHAYA ARGYROPHYLLA IN BAMIAN MOUNTAIN

Genetic diversity and population differentiation of the endangered plant Cathaya argyro-phylla 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 GST value as high as 0.26, which was very different from the published results of other coniferious species. The low in-trapopulationed 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.