Transmission efficiency of Cotton leaf curl Khokhran virus /Cotton leaf curl Multan betasatellite complex by two whitefly cryptic species in Pakistan

Cotton leaf curl disease (CLCuD) is a major constraint in the production of cotton crop across the Africa and Asia which is caused by a complex of begomoviruses (family Geminiviridae). Cotton leaf curl Khokhran virus and associated Cotton leaf curl Multan betasatellite (CLCuKoV/CLCuMB) complex are important agents of CLCuD which transmitted by whiteflies of the Bemisia tabaci species complex. Information regarding the transmission efficiency of CLCuKoV/CLCuMB by whitefly cryptic species is seriously lacking in Pakistan, therefore present study is conducted for comparison of transmission efficiency of CLCuKoV/CLCuMB by two characterized whitefly cryptic species (Asia II-1 and Asia II-5). Whitefly cryptic species were reared separately on Nicotiana benthamiana plants infected with CLCuKoV/CLCuMB for 24 or 48 h and these infected whitefly cryptic species were transferred to un-infected cotton and alternative host plants for 24 or 48 h. The first experiment results showed that Asia II-1 was able to transmit CLCuKoV/CLCuMB with high efficiency in cotton and bitter gourd plants as compared to the Asia II-5 while other host plants did not develop symptoms. Further in the second experiment results revealed that Asia II-1 was able to transmit CLCuKoV/CLCuMB with high efficiency from symptomatic bitter gourd to cotton plants as compared to Asia II-5 which did not show symptoms of transmission. Infection symptoms were confirmed by visual inspection after 30 days and PCR analysis. We found the percentage of virus infection symptoms in alternate host plants differed between two whitefly cryptic species due to varying transmission efficiencies. This research finding advances our understanding to explore the whitefly cryptic species involved in the transmission of CLCuD and will aid in the development of management strategies for control of whitefly cryptic species and CLCuD transmission in Pakistan.

Automated summary

This study compared the transmission efficiency of Cotton leaf curl Khokhran virus and associated Cotton leaf curl Multan betasatellite (CLCuKoV/CLCuMB) by two characterized whitefly cryptic species (Asia II-1 and Asia II-5). The results showed that Asia II-1 had a higher transmission efficiency in cotton and bitter gourd plants, while Asia II-5 did not show symptoms in other host plants. These findings contribute to our understanding of the role of whitefly cryptic species in CLCuD transmission and will help in developing management strategies for controlling whitefly cryptic species and CLCuD transmission in Pakistan.