Molecular detection of Tomato leaf curl New Delhi virus infecting pumpkin plants in sub-Himalayan plains of West Bengal, India

Tomato leaf curl New Delhi virus is a silverleaf whitefly-transmitted bipartite begomovirus that causes damage to various cultivated plant species mainly belonging to the family Solanaceae and Cucurbitaceae. A survey was carried in pumpkin fields of sub-Himalayan plains of West Bengal, India during 2018. During the survey, presence of silverleaf whitefly along with symptoms like leaf curling, leaf yellowing, yellow mosaic, vein clearing and leaf distortion were observed on pumpkin plants. Disease incidences in the range of 30% to 50% were also recorded. Collected infected leaf samples were analyzed for the presence of begomovirus using universal begomovirus primers, DengA/DengB. Amplified PCR products from severely infected plants were cloned and sequenced. All the sequences were completely identical, thus only one representative sequence was submitted to GenBank (Acc. No.MG721010). After BLASTn analysis the causal organism was identified as Tomato leaf curl New Delhi virus. Nucleotide sequence identity of CP gene showed close relationship with Tomato leaf curl New Delhi virus. This study confirmed the emergence of Tomato leaf curl New Delhi virus in the infected fields of pumpkin in sub-Himalayan plains of West Bengal, India.