Genetic diversity of Beauveria bassiana in Dinghu Mountain National Nature Reserve in Guangdong Province

Objective  To understand the population genetic structure, gene flow, strain differentiation of Beauveria bassiana in Guangdong Province, analyze the correlation between genetic variation and host type, ecological environment, and provide a large number of reserved germplasm resources for screening and production of superior strains.

Method  The genetic variation and diversity of 81 B. bassiana isolates from Dinghu Mountain National Nature Reserve of Guangdong Province (DHS) were assessed using SSR markers.

Result  Eight SSR primers were amplified to produce 58 polymorphic points, the percentage of polymorphic loci was 100%, and the number of polymorphic points of primer Ba12 was the largest (10). Nei’s genetic diversity index (h) was 0.212 6 and Shannon’s information index (I_s) was 0.348 7 based on the analysis using the Popgene 32 software package, which indicated the genetic diversity and population heterogeneity levels of B. bassiana were high in DHS. Eighty-one strains of B. bassiana were divided into different subpopulations according to host/soil and insect order respectively. The genetic diversity of soil subpopulation (h=0.192 5, I_s=0.309 9) was slightly higher than that of host subpopulation (h=0.176 9, I_s=0.278 3), suggesting a generally low genetic differentiation among subpopulations (N_m=1.662 9, G_st=0.130 7).Genetic differentiation among subpopulations in different insect order was low and was associated with strong gene flow. The distribution of isolates had no obvious correlation with isolation medium or insect orders based on UPGMA clustering.

Conclusion  The genetic lineage of B. bassiana in DHS is not correlated with isolation medium or insect orders. The diversification of B. bassiana population in DHS is maintained by different ecological environment and host type.