Rakshit Ojha¹ , Sushil K. Jalali¹ , J. Poorani² , K. Srinivasa Murthy¹

1 Division of Molecular Entomology, National Bureau of Agriculturally Important Insects, Post Bag No. 2491, H. A. Farm Post, Bellary Road, Hebbal, Bangalore, Karnataka, India
2 Division of Insect Systematics, National Bureau of Agriculturally Important Insects, Post Bag No. 2491, H. A. Farm Post, Bellary Road, Hebbal, Bangalore, 560024, Karnataka, India
Author    Correspondence author
Molecular Entomology, 2016, Vol. 7, No. 2   doi: 10.5376/me.2016.07.0002
Received: 13 Oct., 2015    Accepted: 24 Nov., 2015    Published: 14 Jan., 2016

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Ojha R., Jalali S.K., Poorani J., and Murthy S.K., 2015, Genetic variation among different Indian populations of cabbage diamondback moth (Plutella xylostella; Lepidoptera: Plutellidae) based on mitochondrial DNA, Molecular Entomology, 6(6): 1-7 (doi: 10.5376/me.2015.06.0006)

Plutella xylostella (L.), commonly known as diamondback moth, is one of the most widely distributed and serious pests of cruciferous crops across the world. To examine the pattern and magnitude of genetic variation in this species in India, a fragment of the mitochondrial (mt) Cytochrome C oxidase subunit I (COXI) gene of P. xylostella collected from thirteen provinces in India, spanning a geographic area of ~ 12250000 km², was sequenced. Sequence analysis of the 658 bp mtCOXI gene from 13 populations resulted in 9 haplotypes, of which 5 populations clustered to form a haplotype group. Among these populations, 11 polymorphic sites were observed, of which 5 were transitional and 6 were of transversional substitution. Phylogenetic analysis in comparison with nucleotide sequences of other countries obtained from GenBank showed that all the populations were highly interrelated. From a geographical perspective, high rates of migration between Indian populations suggest that dispersal of gene flow over considerable distances is a major factor in the development of genetic variability in the species. Nevertheless, we believe that these variations are induced by local selection pressure in insecticide usage, host strain variation and cultural practices. Our study has revealed that Indian populations of P. xylostella are not homogeneous and use of DNA barcoding with more suitable markers can resolve the issues related to the demography of the species.

Plutella xylostella; Genetic variation; Indian populations; Mitochondrial DNA COXI; DNA barcoding