10个南方皂荚群体遗传多样性的AFLP分析

Genetic Diversity of Ten Gleditsia sinensis Populations from Southern China

[目的]研究南方皂荚的遗传多样性和遗传结构现状,为制定有效的保护策略和育种策略提供理论依据。[方法]采用扩增片段长度多态性技术对供试的215份皂荚的遗传多样性及遗传距离进行分析。[结果]表明:检测到1 782个位点,其中,有1 389个为多态性位点,多态位点百分率为77.94%;皂荚各群体Shannon’s信息指数平均为0.256;Nei’s多样性指数平均为0.168,表明皂荚群体的遗传多样性偏低,皂荚群体间存在着一定的遗传分化;根据遗传距离UPGMA聚类分析,将10个群体划分为4大类。由遗传分化系数和分子方差分析结果发现,群体内的变异是皂荚遗传变异的主体,74.79%的变异来自群体内。[结论]皂荚群体的遗传多样性与遗传结构的形成不仅与其分布广泛、种子特性及生活史有关,而且与人为的砍伐、引种、生境片段化等因素有重要关系。基于上述结果提出了皂荚的保护策略。

[ Objective] To understand the genetic diversity of Gleditsia sinensis. [ Method]215 G. sinensis samples were analyzed using AFLP （amplified fragment length polymorphism） approach. [ Result ] The results showed that total of 1 782 loci of G. sinensis genome were examined for molecular variation in which 1 389 loci were polymorphism, accounting for 77.94%. The average Shannon＇ s and Nei＇ s index were 0. 256 and 0. 168, respectively. At the species level, the total genetic diversity （Ht） was 0. 127, suggesting a lower genetic diversity in G. sinensis populations. The gene flow and average genetic distance were 0. 059 and 1. 483, respectively. It is suggested that there were some genetic differentiations among the ten populations. The UPGMA cluster analysis showed that the G. sinensis populations were divided four types. The variance within population was the main part of the genetic variation of the species according to the AMOVA and Gst analysis. [ Conclusion ] In combination with on-site investigation, it is conclude that the present status of genetic diversity and genetic structure of G. sinensis populations are strongly affected by wide distribution, fruit characteristics, chop, introduction and habitat fragmentation. Some suggestions on the gene conservation of G. sinensis are proposed.