采用空间自相关分析研究两种兰科植物的群体遗传结构  

Spatial autocorrelation study of population genetic structure of two orchid species

作　　者：李昂[1] 罗毅波[1] 葛颂[1] 

机构地区：[1]中国科学院植物研究所系统与进化植物学重点实验室,北京100093

出　　处：《生物多样性》2002年第3期249-257,共9页Biodiversity Science

基　　金：国家重点基础研究发展规划"973"项目 (G2 0 0 0 0 4680 5 );国家自然科学基金重大项目 (3 9893 3 60 2 0 7)

摘　　要：采用空间自相关分析方法对硬叶兜兰 (Paphiopedilummicranthum)和独花兰 (Changnieniaamoena) 4个天然群体的小尺度空间遗传结构进行了研究 ,以探讨两种兰科植物群体内遗传变异的分布特征及其形成机制。根据来自 12个 (硬叶兜兰 )和 16个 (独花兰 )RAPD引物所提供的多态位点 ,计算出每个群体的空间自相关系数MoranI值。结果表明 ,在 2个硬叶兜兰群体中 ,遗传变异在短距离 (3～ 4m)内表现出显著的正相关 ,在较大的距离内表现出显著的负相关 ,说明其遗传变异在群体内形成一定的空间结构。而对独花兰的空间自相关分析则显示 ,其遗传变异在参与计算的 2个群体内不存在明显的空间结构。造成上述两种兰科植物具有不同空间分布特性的原因可能与其不同的繁殖方式有关。上述研究结果有助于进一步了解物种的进化历程和濒危机制 。The spatial pattern or structure of genetic variation within populations is an important part of evolutionary and ecological genetic processes in natural populations of plants, and may provide deep insight into the conservation of endangered species. In this paper, we investigated the spatial distribution patterns of population genetic variation of two orchid species, Paphiopedilum micranthum and Changnienia amoena , using RAPD markers. A total of 89 and 42 individuals in two populations of each of the species, respectively, were involved in our study. Based on the polymorphic bands generated by 12 ( P. micranthum ) and 16 ( C. amoena ) RAPD primers, Moran′s I spatial autocorrelation coefficient was calculated, which revealed significant spatial structure of genetic variation within populations of P. micranthum (with significant positive autocorrelation over short distance class: 3～4 m). In contrast, the genetic variation in C. amoena populations was found to be randomly distributed. The different spatial distribution patterns may be attributed to the different reproductive systems of these two species. P. micranthum undergoes significant clonal growth while no significant clonal reproduction was found in C. amoena . These results have important implications for the conservation and management of these species, especially for the sampling strategies for ex situ conservation.

关 键 词：空间自相关分析 兰科植物 群体遗传结构 RAPD 保护遗传学 硬叶兜兰 独花兰 

分 类 号：Q943[生物学—植物学]