The present study was undertaken to explore the genetic diversity among Helicoverpa
armigera populations from varied geographic regions of India using
mitochondrial cytochrome c oxidase I (COI) gene fragments.
Methodology: The larval specimens of H. armigera collected
from 20 locations were subjected to DNA extraction, PCR amplification of
target gene, sequencing and then multiple sequence alignments.
Based on COI sequence data, high levels of genetic differentiation among some
H. armigera populations were detected, but divergence existing was not
high enough to delineate them as separate species. The Indian population as a
whole exhibited similarity with global genetic assemblage. Significant
negative neutrality test indices and unimodal mismatch distribution further
supported that this insect experienced a demographic expansion in the past.
The phylogenetic tree and median-joining haplotype network indicated that
genetic similarity was not related with geographic proximity of populations.
Interpretation: Differences based on genetic analyses
indicate considerable subspecific level variations among H. armigera
populations of India. However, there is no existence of any unidentified
cryptic species of H. armigera in the country.
COI gene, Diversity, Genetic structure, Haplotype, Phylogeny