Native and Non-Native Bemisia tabaci NAFME Haplotypes Can Be Implicated in Dispersal of Endemic and Introduced Begomoviruses in Oman

Simple Summary Whiteflies (Bemisia tabaci) 'B mitotype' represent an insect pest of fruit, vegetable, ornamental and weed plants. B. tabaci is a cryptic species comprising at least eight endemic haplotypes, of which haplotypes 6 and/or 8 are recognized invasives. The objective of this study was to identify the prevalence and relationships among putative native and exotic begomoviruses and North Africa-Middle East haplotypes in Oman. Several begomoviral species were identified from B. tabaci adults collected from infested plant species, with 67% and 33% representing native and exotic species, respectively. Logistic regression and correspondence analyses predicted 'strong' and 'close' virus-vector associations involving haplotypes 5 and 2 and the exotic chili leaf curl virus and endemic tomato yellow leaf curl virus-OM, respectively. Irrigated agriculture and global trade expansion have facilitated diversification and spread of begomoviruses (Geminiviridae), transmitted by the Bemisia tabaci (Gennadius) cryptic species. Oman is situated on major crossroads between Africa and South Asia, where endemic/native and introduced/exotic begomoviruses occur in agroecosystems. The B. tabaci 'B mitotype' belongs to the North Africa-Middle East (NAFME) cryptic species, comprising at least eight endemic haplotypes, of which haplotypes 6 and/or 8 are recognized invasives. Prevalence and associations among native and exotic begomoviruses and NAFME haplotypes in Oman were investigated. Nine begomoviral species were identified from B. tabaci infesting crop or wild plant species, with 67% and 33% representing native and exotic species, respectively. Haplotypes 2, 3, and 5 represented 31%, 3%, and 66% of the B. tabaci population, respectively. Logistic regression and correspondence analyses predicted 'strong'- and 'close' virus-vector associations involving haplotypes 5 and 2 and the exotic chili leaf curl virus (ChiLCV) and endemic tomato yellow leaf curl virus-OM, respectively. Patterns favor a hypothesis of relaxed virus-vector specificity between an endemic haplotype and the introduced ChiLCV, whereas the endemic co-evolved TYLCV-OM and haplotype 2 virus-vector relationship was reinforced. Thus, in Oman, at least one native haplotype can facilitate the spread of endemic and introduced begomoviruses.

Automated summary

The prevalence and relationships between putative native and exotic begomoviruses and the North Africa-Middle East haplotypes of B. tabaci were investigated in Oman. The study found close associations between various begomoviral species and the B. tabaci insect pest in the region. The results suggest that irrigated agriculture and global trade have facilitated the diversification and spread of begomoviruses.