Genetic Analysis of Brown Planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) Based on Microsatellite Markers

Brown planthopper, Nilaparvata lugens (Stål) is one of the most destructive pests of rice in Southeast Asia. It expresses a differential reaction to resistant rice cultivars and various insecticide groups in different geographic locations. Therefore, genetic diversity among N. lugens populations must be understood for their effective management. Hence, in the present study, the genetic structure and diversity of 22 N. lugens populations collected from 22 hotspot regions of India were analysed using with genomic simple sequence repeat (SSR) markers. Results revealed that the mean genetic diversity was 0.399 and polymorphic information content was 0.337 in the 30 selected SSR markers. Further, molecular variance revealed only a 2% variation among the populations and 98% within a population. In cluster and population structure analysis, all 22 populations were sub-grouped into three groups. Interestingly, the North and West Indian populations showed high genetic similarity and assembled into one cluster in cluster analysis. The East and South Indian populations were evenly segregated into the remaining two clusters. Similarly, the North and West Indian populations shared the same compartment in principal coordinate analysis. This variation might be associated with the N. lugens migration due to wind movement of the southwest monsoon in two branches, viz. Arabian Sea branch and Bay of Bengal branch. The present study provides molecular evidence for genetic variation among different populations of N. lugens in India. The information could be helpful to devise an efficient management strategy against this pest in different rice ecosystems.