云南西双版纳地区羽叶金合欢的遗传多样性研究  

Genetic diversity of natural populations of Acacia pennata in Xishuang-banna, Yunnan

作　　者：高洁[1] 李巧明[1] 

机构地区：[1]中国科学院西双版纳热带植物园植物系统与保护生物学实验室

出　　处：《生物多样性》2008年第3期271-278,共8页Biodiversity Science

基　　金：中国科学院方向性项目(KSCX2-YW-Z-0021);中国科学院知识创新工程青年人才领域前沿项目

摘　　要：羽叶金合欢(Acacia pennata)是一种重要的经济植物。本研究使用微卫星(SSR)分子标记技术对分布于云南西双版纳地区的7个羽叶金合欢自然居群进行了遗传多样性和居群遗传结构的研究,旨在从分子水平探讨其自然居群的遗传多样性,制定科学的保护策略,为今后的持续利用提供科学依据。我们用筛选出的6对SSR引物对采自7个自然居群的124个个体进行了扩增,共检测到23个等位基因。平均观察等位基因数(Na)为3.381,有效等位基因数(Ne)为2.460,平均期望杂合度(He)为0.573,Nei's多样性指数(h)为0.567。其中景洪居群具有较高的遗传多样性,曼腊居群遗传多样性相对较低。遗传分化系数FST仅为0.113。结果表明羽叶金合欢的自然居群具有较高的遗传多样性水平,居群间分化较小,遗传变异主要来源于居群内。羽叶金合欢为多年生植物,分布范围广泛,这可能是其具有较高水平遗传多样性的原因;同时其繁育系统可能为异交,种子可远距离传播,这些特性也可能导致其较高的遗传多样性水平和较低的居群遗传分化。我们建议在对羽叶金合欢进行迁地保护时,要在遗传多样性较高的居群内进行大量取样,同时也要对不同居群进行取样。Acacia pennata is an economically important plant that is used for timber and food by the local people in Xishuangbanna, Yunnan. The objectives of this study were to evaluate the genetic diversity and genetic differentiation of natural populations and present a scientific framework for the conservation and utilization ofA. pennata. We estimated the genetic diversity and genetic structure of seven natural populations in Xishuangbanna using SSR techniques. A relatively high level of genetic diversity was detected in A. pennata using six polymorphic microsatellite loci. Based on six primers, 23 alleles were detected. Average （Na） and effective （Ne） number of alleles were 3.381 and 2.460, respectively. The mean expected heterozygosity （He） was 0.573 and Nei＇s diversity index （h） was 0.567. The highest genetic diversity was found in Jinghong population, while the lowest was found in Manla population. The majority of genetic variation occurred within populations and could have resulted from low genetic differentiation （FST = 0.113）. Acacia pennata is a perennial species with a wide distribution; these characteristics could account for the relatively high genetic diversity we observed. Furthermore, this species has an outcrossing breeding system and its seeds are widely dispersed, a situation amenable to high genetic diversity and low levels of genetic differentiation among populations. Therefore, we should focus on sampling more individuals from populations with higher genetic diversity and sampling different populations for ex-situ conservation of A. pennata.

关 键 词：ACACIA pennata SSR 遗传多样性 遗传分化 

分 类 号：Q943[生物学—植物学] S685.99[农业科学—观赏园艺]