Characterization of Tomato Leaf Curl New Delhi Virus Associated with Leaf Curl and Yellowing Disease of Bitter Gourd from Karnataka, India

Abstract

Aims: The objective of this study was to identify the ToLCNDV isolate responsible for leaf curl and yellowing disease in bitter gourd crops in Karnataka, India. Study Design:  Molecular characterisation and transmission study. Place and Duration of Study: The laboratory studies were conducted in the Department of Plant Pathology, College of Agriculture, University of Agricultural Sciences, GKVK, Bangalore-560065. Methodology: The sample was collected and subjected to molecular characterization using specific primer for ToLCNDV and sent for sequencing. Vector and sap transmission studies were also carried out. Results: PCR-mediated detection revealed the presence of ToLCNDV, although it was not coupled with any satellite molecules. The partial genome sequencing of the AV1 gene revealed more than 97% similarity with ToLCNDV isolates. The isolate under investigation was identified as a ToLCNDV isolate and given the name ToLCNDV_GKVK_BT due to high sequence identities and phylogenetic links between the incomplete DNA-A genome and ToLCNDV isolates. The transmission experiments demonstrated that it was effectively transmitted via vector and sap transfer. Conclusion: This study identified the ToLCNDV isolate responsible for leaf curl and yellowing disease in bitter gourd crops in Karnataka, India. Identifying, characterizing at the molecular level, and understanding the transmission of begomoviruses are essential steps in developing effective management approaches to minimize agricultural losses caused by these viruses. Therefore, these findings are important for identifying the leaf curl disease of bitter gourd.