Application of RNA interference technology for management of yellow mosaic virus in mungbean

Abstract:

Mungbean yellow mosaic virus (MYMV) can wipe out an entire mungbean crop in Punjab within three weeks of symptom onset, and no commercial cultivar carries complete resistance. This research tested whether RNAi constructs targeting the viral replicase (Rep) gene could confer durable resistance in mungbean (Vigna radiata cv. SML-668). Two hairpin-RNA lines (RNAi-Line 1 and RNAi-Line 2) generated via Agrobacterium-mediated transformation were challenged with viruliferous whiteflies under glasshouse and contained-field conditions at Bathinda, Punjab, during Kharif 2022–2023. By 35 days post inoculation, virus titer in RNAi-Line 1 was 81% lower than in the susceptible control. Symptom severity scored 0.8 on a 0–5 scale versus 4.6 in the control. Seed yield of RNAi-Line 1 reached 1.14 t ha^-1, 168% above the unprotected check. Southern blot confirmed single-copy integration, and siRNA accumulation was detected by northern blot. These lines provide strong proof-of-concept that RNAi can manage MYMV where conventional breeding has stalled.