Genetic structure and haplotype analysis of predominant genetic group of Bemisia tabaci Asia II 1 from Asia and India.

Whitefly, Bemisia tabaci is a globally recognized invasive cryptic pest species complex and a primary vector for 90% of begomoviruses. Understanding the species composition and diversity within the B. tabaci cryptic species complex is essential for developing effective pest management strategies. The Asia II 1 genetic group of B. tabaci is notably widespread in India and across Asia, demonstrating significant genetic diversity. Our study investigates the haplotype diversity of Asia II 1 using the mtCOI barcoding gene, analyzing 676 sequences from various Asian countries and 190 sequences from India. We identified 241 distinct haplotypes in Asia II 1 across Asia, with the highest haplotype diversity in China (Hd: 1.000) and the lowest in Vietnam (Hd: 0.667). Nucleotide diversity peaked in Pakistan (pi: 0.0145) and was lowest in Vietnam (pi: 0.0010). In India, we identified 77 haplotypes with a diversity of 0.926 and nucleotide diversity of 0.0076. When grouped by hostplant families, 79 haplotypes were recorded, with the highest diversity in Cucurbitaceae and the lowest in Solanaceae. Our findings suggest that hostplants and geographical location significantly influence genetic group development, offering novel insights into Asia II 1's genetic structure and evolution. This marks the first comprehensive study of Asia II 1 genetic diversity in Asia and India.