Detection of a tospovirus associated with necrotic leaf curl disease of mungbean at Kanpur

The causal virus of a necrotic leaf curl disease of mungbean at Kanpur was mechanically sap transmissible from field infected mungbean to healthy mungbean and cowpea. Reverse transcriptase-PCR using primers for amplification of nucleocapsid protein (NP) gene of Groundnut bud necrosis virus (GBNV), a tospovirus yielded a single band of ~800 bp. Comparison of the virus under study with the isolates of GBNV from leguminous hosts revealed 97% homology with GBNV – Type isolate, GBNV-MB and GBNV-VU at nucleotide level. At amino acid level, the present virus isolate showed 99% homology with GBNV-Type and GBNV-MB and 98% with GBNV-Mb and 96% with GBNV-VU and GBNV-SE. Sequence analysis of amplified product revealed that the virus causing necrotic leaf curl disease of mungbean at Kanpur is a strain of GBNV and has been named as GBNV-MBKN.