Diagnosis of leaf curl and crooked tip diseases on tobacco plants in Tay Ninh Province, Vietnam
Tobacco leaf curl and crooked tip disease causes regular damage in the Tay Ninh Province of Vietnam and resulted in serious tobacco yield and quality loss in 2019. To define exactly the cause of the disease, the Tobacco Institute collected seven disease samples from tobacco growing in the Tay Ninh Province for analysis by the Research Centre for Tropical Plant Pathology – Vietnam National University of Agriculture. The analyses was done by RT-PCR and gen sequence methods with the following pair of primes: TYKan-A-F1 and TYKan-A-R1 (to identify DNA-A of TYLCKanV), size: 698 bp; TYKan-B-F1 and TYKan-B-R2 (to identify DNA-B of TYLCKanV), size: 402 bp; Krusty and Homer (to identify DNA-A of Begomovirus), size 600 bp; BegoA-For1 and BegoA-Rev1 (to identify DNA-A of Begomovirus), size: 1200 bp. Results of the analyses determined two species of virus, which include tomato yellow leaf curl Kanchanaburi virus (TYLCKaV) and pepper yellow leaf curl Indonesia virus (PepYLCIDV). These cause the same disease symptoms on tobacco plants and belong to the Begomovirus genus and are spread by Bemisia tabaci. The pepper yellow leaf curl Indonesia virus was detected for the first time in Vietnam. This result is an important basis to decide proper management and reduce tobacco losses due to the disease in the 2020 season in Tay Ninh Province.