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

Abstract

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.

Sentinel plot surveillance of cotton leaf curl disease in Pakistan- a case study at the cultivated cotton-wild host plant interface

“…The annual establishment of sentinel plots for CLCuD surveillance would facilitate early-recognition of new or re-emergent virus variants with a potential for resistance- breaking, increased virulence, and/or host range shifts. Similarly informative, parallel tracking of the predominant whitefly vector haplotypes, which occupy different environmental niches ( Paredes-Montero et al., 2019 ; Paredes-Montero et al., 2020 , Paredes-Montero et al., 2021 ; Paredes-Montero et al., 2021 ; Shah et al., 2020 ), can vary in begomovirus-transmission competencies ( Pan et al., 2018 , Pan et al., 2020 , Shahid et al., 2023 ) and differ in the propensity for developing insecticide resistance, would go far to inform knowledge-driven CLCuD management practices that result in reduced damage to the cotton crop in Pakistan.…”