Prevalence and Molecular Diversity of Tomato Leaf Curl Virus (ToLCV) in Eastern Dry Zone of Karnataka

Tomato ( Solanum lycopersicum L.) is an economically important vegetable crop cultivated widely across India, valued for its nutritional content and income generation for smallholder farmers. In the Eastern Dry Zone of Karnataka, tomato is grown intensively year‐round; however, production is severely constrained by tomato leaf curl disease (ToLCD), caused by tomato leaf curl virus (ToLCV), a whitefly‐transmitted begomovirus. This study aimed to investigate the prevalence, molecular diversity, and transmission dynamics of ToLCV during the 2024 and 2025 cropping seasons across five key tomato‐growing districts of Karnataka: Bengaluru Rural, Bengaluru Urban, Chikkaballapura, Kolar, and Ramanagara. Field surveys revealed high disease incidence, with Kolar and Chikkaballapura, highlighting their status as disease prevalence zones. PCR‐based detection using universal and strain‐specific primers confirmed the dominance of tomato leaf curl Bangalore virus (ToLCBV), compared to tomato leaf curl Karnataka virus (ToLCKV) and tomato leaf curl New Delhi virus (ToLCNDV). Sequencing and phylogenetic analysis validated the genetic identity of 15 isolates showing the highest disease severity of ToLCD. Virus transmission studies using whitefly‐mediated inoculation under glasshouse and field conditions with ToLCV‐susceptible varieties indicated that Pusa Ruby exhibited faster symptom development and higher infection rates compared to Arka Vikas . These results confirm the virulence and adaptability of ToLCBV in this region. These findings highlight the need for specific integrated disease management strategies, including resistant cultivar development, vector control, and continuous surveillance, to mitigate the impact of ToLCD on tomato production.