Genetic Diversity of Mythimna separata (Walker)(Lepidoptera: Noctuidae) in Yunnan Province

The oriental armyworm, Mythimna separata (Walker) is a major agricultural and migratory pest in Yunnan Province. To verify the genetic diversity of oriental armyworm, the genetic diversity and genetic structure of 23 M. separata populations in Yunnan Province were analyzed by inter-simple sequence repeat (ISSR). The results showed that 9 primers were selected among 100 primers and 198 loci were detected by ISSR marker analysis. The percentage of polymorphic loci (P) was 44.95%-66.16%, the Xisa population was the highest among 23 populations, the lowest polymorphic loci was in the Midu population. Coefficient of gene differentiation (Gst) among 23 populations was 0.3, showed that the genetic variation among individuals in the same population (70%) was higher than that of among populations (30%). Gene flow (Nm) among those populations was 1.669, the average of genetic similarity was 0.898 2, and the Mantel test results suggested that there was no significant correlation between the genetic distance and geographic distance of different M. separata populations(r=-0.085 6,P=0.282 0). Overall, the genetic diversity of armyworm in Yunnan Province was high, and there was genetic differentiation among different geographic populations. Moreover, the population genetic structure similarity was high and armyworm could prevent genetic drift caused by genetic differentiation among those 23 populations. The results in this paper can provide some new ideas for integrated pest management of M. separata.