Population genetic structure of the cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in India as inferred from EPIC-PCR DNA markers

PLoS One. 2013;8(1):e53448. doi: 10.1371/journal.pone.0053448. Epub 2013 Jan 11.

Abstract

Helicoverpa armigera is an important pest of cotton and other agricultural crops in the Old World. Its wide host range, high mobility and fecundity, and the ability to adapt and develop resistance against all common groups of insecticides used for its management have exacerbated its pest status. An understanding of the population genetic structure in H. armigera under Indian agricultural conditions will help ascertain gene flow patterns across different agricultural zones. This study inferred the population genetic structure of Indian H. armigera using five Exon-Primed Intron-Crossing (EPIC)-PCR markers. Nested alternative EPIC markers detected moderate null allele frequencies (4.3% to 9.4%) in loci used to infer population genetic structure but the apparently genome-wide heterozygote deficit suggests in-breeding or a Wahlund effect rather than a null allele effect. Population genetic analysis of the 26 populations suggested significant genetic differentiation within India but especially in cotton-feeding populations in the 2006-07 cropping season. In contrast, overall pair-wise F(ST) estimates from populations feeding on food crops indicated no significant population substructure irrespective of cropping seasons. A Baysian cluster analysis was used to assign the genetic make-up of individuals to likely membership of population clusters. Some evidence was found for four major clusters with individuals in two populations from cotton in one year (from two populations in northern India) showing especially high homogeneity. Taken as a whole, this study found evidence of population substructure at host crop, temporal and spatial levels in Indian H. armigera, without, however, a clear biological rationale for these structures being evident.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Animals
  • Exons / genetics*
  • Gene Frequency / genetics
  • Genetic Markers
  • Genetic Variation
  • Genetics, Population
  • Geography
  • Gossypium / parasitology*
  • India
  • Introns / genetics*
  • Moths / genetics*
  • Polymerase Chain Reaction / methods*
  • Specimen Handling

Substances

  • Genetic Markers

Grants and funding

GTB was supported by grants from the Melbourne International Research Scholarship (MIRS), the Melbourne International Fee Remission Scholarship (MIFRS), and the Albert Shimmins Post Graduate Writing-up Award (Faculty of Science, University of Melbourne). The Australian Research Council (ARC) provided funding to the Special Research Centre for Environmental Stress and Adaptation Research (CESAR). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.