Population genetic structure of cotton pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) from India

Abstract

Background Pink boll worm, Pectinophora gossypiella became serious pest on BG II cotton hybrids globally causing huge economic losses in cotton even during later stages of crop growth. Understanding the genetic background and diversity of insect pests can aid in understanding their evolution in changing environments, hence aiding in effecting their management in an agricultural ecosystem. Results In the present investigation, the population genetic structure, distribution, and genetic diversity of P.gossypiella in cotton growing zones of India using partial mitochondrial DNA cytochrome oxidase-I (COI) gene was addressed. Results revealed a total of 9 haplotypes (17.64%) identified from 51 individual sequences distributed in 16 populations belonging to different cotton growing zones of India. Diversity analysis of COI sequences revealed low genetic diversity (0.000 to 0.01066), high haplotype diversity (0.800), low nucleotide diversity (0.002), negative Tajima D (-0.670) values and high gene flow. Conclusion This data on population genetics indicate populations of pink bollworm are genetically similar and in Median Joining network Hap5 occupied central position and connected by low frequency haplotypes which are formed due to one or two point mutations indicating recent population expansion from limited number of founders due to post-Pleistocene warming and with the domestication range of hosts. Neutrality tests also support low frequency polymorphisms in the population consistent with the recent population expansion after bottleneck or selection sweep.