Population structure and introduction history of the pink bollworm, Pectinophora gossypiella, in China

Abstract

The pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), a cotton pest probably native to Indo‐Pakistan, invaded China at the beginning of the 20th century. Chinese P. gossypiella have been assumed to be the result of indiscriminate introductions from Pakistan and America by transport of cotton seed. We tested this long‐held hypothesis and genotyped a total of 527 individuals from 14 sites at 13 microsatellite loci. We analyzed these data with traditional statistics as well as with Bayesian methods. The loci were, for the most part, highly polymorphic. The allelic richness of Chinese populations at six loci was greater than those of the Pakistani and American populations. Significant deficits of heterozygotes were recorded for all 14 populations, and null alleles were the most probable factor contributing to these deficits. Pairwise FST estimates showed that there was significant differentiation among the pooled Chinese, Pakistani, and American populations, and there was structure within most of the Chinese populations. The Bayesian analysis revealed that the combined Chinese, American, and Pakistani populations formed separate clusters, and the nine Chinese populations were divided into two clusters. Allelic frequency distributions showed that private and shared alleles within Chinese P. gossypiella were derived only partly from the Pakistani and American populations. The microsatellite‐based genetic analyses suggested that the Chinese P. gossypiella populations originated from multiple sources.

Evidence for population expansion of Cotton pink bollworm Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) in India

“…After a careful alignment of the 214 COI mitochondrial gene sequences, we have investigated the genetic diversity and structure of 214 individuals of 44 populations sampled throughout their main area of distribution in India. The mitochondrial DNA sequence region was used in this study because it is more prone to genetic drift than nuclear markers and because of the smaller effective population size and maternal gene flow 35,48,49 . www.nature.com/scientificreports www.nature.com/scientificreports/ The studies revealed that total of 27 unique haplotypes were identified in 214 individuals from all over India, with low values of nucleotide and haplotype diversity and is supported by Sridhar et al 34 where they found 12 (15.18%) haplotypes in 79 individuals distributed in 19 populations of Indian subcontinent.…”

“…Studies on population structure and genetic diversity of PBW has been explored more in Asiatic countries such as India, Pakistan and China owing to the development of resistance to Bt cotton by PBW populations [32][33][34] . Liu et al 35 studied the population genetic structure of Chinese PBW using mitochondrial COII and Nad4 primers, and found extremely low genetic variability among all populations examined from nine provinces of China. Sequence variation in the Nad4 region differentiated the Chinese populations from the Pakistani and American populations.…”

Limited emigration from an outbreak of a forest pest insect

“…The large number of unique alleles in the Gry population, as compared with all other populations, suggests that the Gry population does not originate from any of the other populations (cf. Liu et al. 2008; Nyingi et al.…”

Managing Practical Resistance of Lepidopteran Pests to Bt Cotton in China

“…The pink bollworm ( P. gossypiella ) has been found in various cotton regions in China, spreading to the Yangtze River Basin Cotton Region (CRR) [ 8 , 66 ]. Unlike the cotton bollworm, which has a variety of host crops other than cotton, the pink bollworm mainly feeds on cotton.…”