Intra-species variation and geographic differentiation among the populations of the quarantine agricultural pest leucinoides orbonalis (lepidoptera: Crambidae) in the global assemblage - a prospective of DNA barcoding.

Abstract

Leucinodes orbonalis Guenée is serious quarantine pest occurring globally, studies are needed to enlighten the genetic complexities associated with the species. India is considered to be the origin of the L. orbonalis, therefore availability of species records from this region enable to analyse the genetic differences and dispersal of the lineages. The results of the study reported 47 haplotypes in four clusters pertaining to their ancestral lineage. The transition/transversion bias (R) was observed to be higher with 1.238 and 1.312 in the first and third codon positions respectively. The overall intraspecies divergence was found to be 0.302. AMOVA revealed that the total variations were then as reported 67.15 among the south-east countries but our studies reported the total variation to be 77.25% (Germany, India, South east and Australia). F_ST and Mantel's test indicated that there was no correlation between the genetic variation and geographical distance. The overall haplotype diversity was 0.852, where the nucleotide diversity of H31 (0.00593) was highest and H1 (0.00087) was lowest. The genetic diversity indices Tajima D and Fu's Fs static for H1, H13 and H31 had negative values which possibly inferred for the bottle neck effect. The ML tree was constituted the branch length of 5.0157 with one out-group. The tree was formed with ten distinctive clades with the haplotypes congregated together based on similar genetic composition.