Mitochondria COI-based genetic diversity of the leafhopper Amrasca biguttula (Ishida) populations in okra in Chhattisgarh state of India

Leafhoppers are one of the key pests causing serious yield losses in important agricultural crops including okra and cotton in India. The leafhoppers cause severe damage to okra in warmer climatic conditions. A comprehensive investigation was carried out on the genetic diversity and population genetic structure of Amrasca biguttula (Ishida) infesting okra in twenty-six locations covering three distinct agroecological zones of Chhattisgarh state of India using mitochondrial COI gene. The genetic analysis showed a Tajima’s D value of 5.5007 (P-value: 8.00087e-17), two parsimony-informative sites, a nucleotide diversity (π) of 0.115, and 81 segregating sites. Population analysis using reticulate trees identified seven low-diversity haplotypes, with CLHH 7 (Chhattisgarh Leafhopper Haplotype 7) being the most dominant haplotype across the Chhattisgarh. Neighbor-Joining phylogenetic analysis revealed that the overall population is primarily monophyletic, except for six populations from central and southern Chhattisgarh, which are paraphyletic. The overall mean genetic diversity of A. biguttula in okra was very low across the three geographical zones. Very low nucleotide substitution rate of COI sequences indicated a clear mutational risk within the A. biguttula populations in Chhattisgarh. The present study reports very low genetic diversity among populations of A. biguttula on okra including seven haplotypes of which CLHH7 being most predominant.