引致蝉若虫地方病的蝉棒束孢种群遗传结构

Population genetic structure of Isaria cicadae causing enzootic of cicadas nymphs

采用ISSR分子标记技术对在3个不同地区引起蝉若虫地方病的蝉棒束孢种群遗传结构进行研究.结果表明:3个地方病种群均表现出较高的遗传多样性,其中敬亭山种群的遗传多样性最高,石台种群最小.UPGMA聚类分析表明,不同地方病种群无优势性,均为多系的异质种群,遗传谱系与地理来源无关.敬亭山不同采集时间的菌株表现出明显的时间异质性种群(亚种群)间的遗传分化系数G_(sl)为0.2153,而基因流N_m为0.9110(N_m<1),暗示低水平的基因交流是种群内遗传变异的主要原因之一.因此,蝉棒束孢种群水平的高异质性和低优势性是维持蝉若虫地方病的遗传结构特征.

The population genetic structure of lsaria cicadae, which caused enzootic of cicadasnymphs populati in three regions, was analyzed by ISSR marker. The results showed that all three ons showed high genetic diversity with the highest in the Jingtingshan population lowest in the Shitai population. The UPGMA clustering analysis revealed that different populations did not have a predominant lineage but were polyphyletic and heterogeneous. enzootic and the enzootic Genetic lineages had nothing to do with geographical origin. However, two subpopulations of Jingtingshan from different sampling periods were gathered into different clades, which exhibited remarkable tem- poral heterogeneity. The genetic differentiation （Gst） among populations （subpopulations） was 0.2153 and the gene flow was low at 0.9110 （Nm〈1）, which indicated the low gene flow was one of the main reasons for the genetic variation in the population. Therefore, high heterogeneity and low dominance might be genetic structure characteristics of I. cicadae population causing enzootic of cicada nymphs.