濒危植物长柄双花木生态遗传分化的同工酶分析

Isozymes analysis of genetical differentiation of the endangered plant Disanthus cercidifolius var.longipes H.T.Chang(Hamamelidaceae)

采用同工酶电泳技术,聚类及主成分分析程序,对分布在井冈山的长柄双花木(Disanthus cercidifolius var.longipes H.T.Chang)5个种群在同工酶水平上的生态遗传分化进行了研究。结果表明:长柄双花木总体生态遗传分化程度很低,基因分化系数Gst仅为0.12,有约88.0%的遗传多样性来自于种群内部;推算种群间的分化时间4.1万年到65.3万年不等;由于生境破碎,该物种趋于"岛屿状"分布,如果其生境保护不当, 该物种将有灭绝的可能。

With the helps of the assay of vertical polyacrylamide gel electrophoresis of five kinds of isoaymes and the computerized numerical analyses of the Jaccard association coefficients clustered by UPG- MA and PCA of two-state allozymic data in 5 populations of Disanthus cercidifolius var.longipes H.T.Chang in Mt. Jinggang. The results show that Disanthus cercidifolius vat. longipes maintains relatively low genetic differentiation among populations with the GST of 0.12 and Nm of 2.30. The low genetic differentiation of this species may relate to the distance of its pollen transfer; dispersing pattern of seeds and intensity of gene flow among populations. It is referred that the populations began to diverse genetically from 41 000 to 653 200 years in the past. Because of the fragmentation of its habitat, the species is tending to be with small populations isolated with each other to some extent. If the favorable habitats of the species can not be protected properly, Disanthus cercidifolius var. longipes H.T.Chang would most probably be extinct.