猕猴桃自然居群SSR遗传变异的空间自相关分析  

Spatial genetic structure in natural populations of two closely related Ac-tinidia species(Actinidiaceae) as revealed by SSR analysis

作　　者：刘亚令[1] 李作洲[2] 张鹏飞[3] 姜正旺[2] 黄宏文[1] 

机构地区：[1]华中农业大学园林学院,武汉430074 [2]中国科学院武汉植物园,武汉430074 [3]信阳农业高等专科学校园艺林学系,河南信阳464000

出　　处：《生物多样性》2006年第5期421-434,共14页Biodiversity Science

基　　金：中国科学院武汉植物园创新主任基金(05035117);中国科学院知识创新方向性项目(KSCX2-SW-320和KSCX2-SW-104)

摘　　要：本研究采用空间自相关分析方法对同域分布的中华猕猴桃(Actinidiachinensis)和美味猕猴桃(A.deliciosa)自然居群SSR遗传变异的空间结构进行了研究,以探讨猕猴桃自然居群遗传变异的分布特征。选用的9对SSR引物在两物种中共扩增出104个等位基因。选择频率在20–80%的SSR等位基因,运用等样本对频率方法分别对同域分布的中华猕猴桃和美味猕猴桃各1个居群及其中华/美味猕猴桃复合居群进行了空间自相关系数Moran’sI值计算。结果表明:中华猕猴桃和美味猕猴桃的遗传变异在居群内均存在着一定程度的空间结构,尽管近半数或半数以上的等位基因在居群内表现为随机分布的空间模式,但也有相当比例(29.6–48.0%)的等位基因在种内居群中和复合居群中(河南西峡51.0%,陕西商南44.7%)呈现渐变、衰退、双向衰退或侵扰模式。而且其居群内遗传变异的空间分布规律,不论是在种内还是复合居群中都基本一致:相距在100m以内,特别是30m范围内的个体间的等位基因表现出显著性的正相关,但随着地理距离的增大逐渐显示出负相关,说明猕猴桃属植物的有效传粉距离可能在100m左右,种子散播主要集中在30m的近距离内。猕猴桃自然居群遗传变异的空间结构是其传粉和种子散播等生物学特性与生境共同作用的结果,其中种子近距离的散播、花粉传播的有限距离及人为干扰是最主要的因素。本研究结果揭示了这两个近缘物种居群遗传变异的空间分布特征及相互关系,有助于进一步探讨猕猴桃属植物的遗传变异、居群扩散及其地理系统发育进化等方面的规律,并为制定相应的保育策略和措施提供基础数据和科学依据。The spatial structure of genetic variation is an important part of evolutionary and ecological genetic processes in natural populations of plants, and may provide deep insights into the conservation of species. In this paper, the spatial distribution patterns of genetic variation of two closely related sympatric species, Actinidia chinensis and A. deliciosa, were investigated using SSR markers. A total of 104 alleles was scored by nine pairs of SSR primers in two natural populations, and the alleles with frequency ranging from 20% to 80% were chosen and then used to calculate Moran＇s I spatial autocorrelation coefficients for the two individual species or the species complex （A. chinensis/A, deliciosa） based on equal numbers of paired samples. Over half of the alleles were found to have a random distribution pattern within populations, while a large proportion of alleles occurred as cline, depression, double depression or intrusion patterns （29.6-48.0% within populations of each individual species, 51.0-44.7% for the two species complex, in Xixia of Henan and Shangnan of Shaanxi populations, respectively）. This suggests that a moderate spatial structure of genetic variation occurred within the natural populations of the two species. Moreover, a similar spatial distribution pattern of genetic variation was found within the two populations of each individual species and in the species complex at the two sampled locations. The results showed that allelic variation for individual plants within 100 m （and especially within 30 m） distance had significant positive correlation, but changed into a negative correlation with increasing distance, which may imply that the distances for pollen dispersal is about 100 m, and seed dispersal might be restricted to within 30 m. The different spatial structures of genetic variation of Actinidia natural populations were influenced by a combination of the biological characteristic of pollination, seed dispersal, and natural habitat. The restricted seed and pollen dispers

关 键 词：ACTINIDIA CHINENSIS ACTINIDIA deliciosa 空间遗传结构 微卫星 Moran's I指数 

分 类 号：Q943[生物学—植物学] S663.4[农业科学—果树学]