Genetic Diversity Of Beauveria Bassiana In Different Geographical Origin

Beauveria bassiana is an important and widely distribution entomopathogenic fungi, has been widely used for agricultural and forestry pest control. Becaused of its widely ranged hosts, the population structure was very complicated. In this paper, two methods was used, ITS sequence analysis and molecular markers ISSR, to study the genetic diversity and population genetic structure of B.bassiana which from China and other countries.Ninety isolates of B. bassiana collected from 11 provinces in China and 3 other countries like France were divided into 14 provincial populations. For Jilin province, subdivided into 9 different groups again, and 3 groups according to the different hosts resistance types. The major results are listed as follows:1. ITS sequence analysis: the phylogenetic tree analysis by results of B. bassiana ITS-PCR, showed that the tested strains of kinship has no correlation with the geographical origin.2. The polymorphism analysis of ISSR primers: a total of 90 fragments were amplified by 10 primers, the percentage of polymorphic loci(PPL) of the 10 primers were 100%, and showed good reproducibility, indicating that the ISSRs are good markers to evaluate the genetic diversity of B. bassiana.3. Genetic diversity analysis: the total PPL of all isolates in north China was 100%, Nei’s gene diversity index(He) was 0.3253, Shannon’s information index(Is) was 0.4930. But Genetic diversity index of each group are quite different. Among them, Jilin group and Shandong group showed highest genetic diversity and highest populational heterogeneity, respectively, while Liaoning group showed the lowest. For Jilin province, the highest genetic diversity and highest populational heterogeneity were Yushu group and the 1st generation group, Shuangliao group and the one and two mixed generation group showed the lowest.4. The intergroup genetic differentiation: The provincial subpopulations of B. bassiana: the mean genetic differentiation coefficient(Gst) was 0.6909, the gene flow(Nm) was 0.2236, The genetic differentiation indices between Liaoning and Hubei groups was the highest. For Jilin Province, the highest genetic differentiation indices was between Shuangliao and Tonghua groups. With the transition from 1st generation to the 2nd generation, the genetic differentiation coefficient increases. The results suggest that the degree of genetic differentiation of various types of B. bassiana groups were independent with location, but genetic differentiation with the type of host generation in Jilin Province.5. Genetic distance(D): genetic distance(D) of the provincial subpopulations was between 0.0464~0.5267, The genetic distances between Hebei and Guangdong Groups was the highest. For Jilin Province, the highest genetic distances were between Lishu and Tonghua Groups and between 1st and 2nd generation groups. This was the same result obtained the intergroup genetic differentiation.6. Cluster analysis: cluster diagram of B. bassiana showed that its distribution had no correlation withthe geographical origin.These results suggestted that:There has no significant relationship with geographic distance for genetic diversity of B.bassiana, neither in China and abroad or in Jilin Province. But the genetic diversity for Jilin strains has a correlation of O. furnacalis resistance type.