竹叶眼子菜居群遗传多样性和克隆结构

采用ISSR技术对长江中游南岸豹澥湖和大冶湖不同生境中的竹叶眼子菜(Potamogeton malaianus)居群的遗传多样性及克隆结构进行了研究.结果表明，在两居群的106株个体中，利用6条ISSR引物共得到40条符合3/N标准并无连锁不平衡的清晰位点，竹叶眼子菜具有较高的遗传多样性，其多态位点百分率为75.0％，Shannon多样性指数为0.3736， 两居群的遗传分化很小.竹叶眼子菜的克隆多样性很高(D=0.9917)，两居群间的克隆分化很大，不具有共有的基因型.竹叶眼子菜的基株分布为游击型构型，位于湖心的大冶居群克隆距离(3.0～31.5 m)明显地大于湖岸豹澥居群(2.4～6.7 m).

Genetic diversity and clonal structure of Potamogeton malaianus populations

By using inter-simple sequence repeat (ISSR) makers, this paper studied the genetic diversity and clonal structure of two Potamogeton malaianus populations growing in different habitats of two lakes in the middle reaches of Yangtze River. With six primers selected, a total of 40 fragments, of which 30 (75.0%) were polymorphic, were obtained from 106 individuals. This species showed a high genetic diversity, with Nei's gene diversity of H = 0.2471 and Shannon' s information index of I = 0.3736. A low degree of population differentiation (G(st) = 0.0861) was found between the two populations, and a very high clonal diversity (D = 0.9917) was detected, according to the analysis based on the polymorphic loci. No common genotypes were found among the individuals from the two populations, showing a great clonal differentiation between them. The spatial distribution pattern of P. malaianus genets showed 'guerilla' architecture, and the clonal distance of the population in lake center (3.0 - 31.5 m) was significantly larger than that in lakeshore (2.4 - 6.7 m).