Multiple and mixed infections with yellow mosaic, leaf crinkle and bud necrosis disease complex in mungbean: A threat to cultivation of mungbean in India

Abstract

The occurrence, incidence, yield losses and diagnostics of yellow mosaic disease (YMD) caused Mungbean yellow mosaic India virus (MYMIV), bud necrosis disease (BND) caused by Groundnut bud necrosis virus (GBNV) and Urdbean leaf crinkle disease complex (ULCD) were studied in mungbean (Vigna radiata) in Delhi condition. Eighteen mungbean cultivars were grown for successive four years from 2006 to 2009. Overall disease incidence of 11.6–18.5% for YMD; 14.4–20.5% for ULCD and 9.4–14.5% for BND were estimated. The mixed infection was studied in kharif season and overall it was 10.5% for YMD+ULCD, 8.3% for YMD+BND, 6.8% for ULCD+BND and 4.3% for YMD+ULCD+BND. None of the mungbean cultivars exhibited resistance to any of the three diseases. Yield loss estimated in susceptible mungbean cv. PS 16 was up to 61.1, 91.0 and 76.8% over control for YMD, ULCD and BND, respectively. Mixed infection with YMD and BND caused 92.8% yield losses. Biological and molecular detection using enzyme linked Immuno-sorbent assay (ELISA), polymerase chain reaction (PCR) and nucleotide analysis determined that MYMIV is the causal agent of YMD and GBNV of BND. Although etiology of ULCD was not confirmed, however, seed and sap transmission study showed that it is caused by an infectious agent.