中国板栗居群间等位酶基因频率的空间分布

Spatial Structure of Allozyme Frequencies in Castanea mollissima Bl.

中国板栗 2 1个自然居群间等位酶遗传变异的空间自相关分析及 F-统计分析结果表明 :其多数等位基因频率在居群间呈随机分布模式 ,缺乏一定的空间结构 ;而部分等位基因表现为渐变或双向渐变的非随机分布模式 ,又具特定空间结构。中国板栗遗传变异空间结构模式的形成可能是长距离基因流、自然气候、人类活动、地理距离隔离等诸因素综合作用的结果。文中还就居群等位基因分布格局的成因进行了讨论 :在第四纪冰川后 ,中国板栗以长江流域中下游的孑遗中心为起点 ,等位基因分别沿着向北和向南的不同方向迁移形成现在的居群结构 ;季风气候和人类活动干扰是削弱居群分化的主要因素 ,而基于环境梯度的选择 。

Spatial differentiation of allozymes among 21 natural populations of Castanea mollissima was investigated using F statistics and spatial autocorrelation analysis.Most alleles were found to be random spatial patterns and lack of spatial structure,while a few were non random patterns of cline or double cline with apparent spatial structure.The spatial patterns of genetic differentiation in C.mollissima populations appeared to be a combining result of long distance gene flow,climate factors,human activities,and local effects of geographic isolation.The spatial structure was consistent with the hypothesis that Yangtze River valley should be the relict centre,which gave rise to northern and southern populations after the last glacier.The monsoon and human activities were probably the factors in shaping the spatial genetic structure of C.mollissima populations,while the ecological gradient selection created the cline distribution from North to South.