中文摘要：

将在中国北方13省采集分离的622株球孢白僵菌按省份划分成13个亚种群，其中寄主可以鉴定到目的8目昆虫和蜘蛛目的568株按目划分成9个亚种群，用ISSR（简单重复序列区间）分子标记技术进行遗传多样性和种群遗传结构分析．结果表明：各多样性指数皆显示我国北方地区球孢白僵菌的遗传多样性水平较高，种群的异质性较强．其中内蒙古亚种群的遗传多样性和种群异质性最高，河南亚种群最低；鳞翅目亚种群的遗传多样性和种群异质性最高，蜘蛛目亚种群最低．河南与辽宁亚种群间以及蜘蛛目与螳螂目亚种群间的遗传分化系数以及遗传距离最大，宁夏与陕西亚种群间以及鞘翅目与膜翅目亚种群间最小．按寄主目划分的亚种群间的平均遗传分化系数和平均遗传距离均低于按省份划分的亚种群．这些结果以及基于遗传距离的亚种群聚类分析都证明我国北方球孢白僵菌的遗传谱系与寄主来源和地理来源均无关系．我国北方球孢白僵菌的变异主要是由各不同寄主目内科间及属间的变异造成的，也是由各省不同采集地以及采集地内部不同微生境间的差异造成的．

英文摘要：

A total of 622 isolates of Beauveria bassiana collected from 13 provinces in northern Chi- na were divided into 13 provincial subpopulations, and 568 of the 622 isolates belonging to 8 insect orders and Araneida, whose hosts could be indentified to order level, were divided into 9 host order subpopulations, with the genetic diversity and population genetic structure of the B. bassiana in northern China analyzed by using ISSR （inter-simple sequence repeat） technique. All the diversity indices showed that the B. bassiana in northern China had higher genetic diversity and population heterogeneity. Among the B. bassiana subpopulations, Inner Mongolia subpopulation and Lepidop- tera subpopulation showed the highest genetic diversity and population heterogeneity, while Henan subpopulation and Araneida subpopulation showed the lowest ones. The genetic differentiation index and genetic distance between Henan and Liaoning subpopulations and between Araneida and Man- todea subpopulations were the highest, while those between Ningxia and Shaanxi subpopulations and between Coleoptera and Hymenoptera subpopulations were the lowest. The mean genetic differentia- tion index and mean genetic distance between the host order subpopulations were lower than those between the provincial subpopulations. These results and the subpopulation clustering analysis based on the genetic distance of subpopulations all demonstrated that the genetic lineage of B. bassi- arta isolates in northern China was associated with neither their geographic origin nor their host ori- gin. The variation of B. bassiana in northern China was mainly caused by the variation between families and between genera of different host orders, and also, caused by the diversity between dif- ferent collection sites and between different microhabitats within the collection sites.