Identification and molecular characterization of Bean yellow mosaic virus infecting French bean in Himachal Pradesh.

French bean (Phaseolus vulgaris L.), is one of the most widely grown vegetable crop. Disease samples showing yellow mosaic symptoms on leaves and pods were collected from Himachal Pradesh and inoculated on common bean cv. Jawala through sap inoculation. The virus successfully transmitted by mechanical inoculation produced yellow mosaic, leaf distortion, curling, wrinkling of leaves followed by stunting of plants. The identity of the virus as Bean yellow mosaic virus (BYMV) was established through Double antibody sandwich-enzyme linked immunosorbent assay, multiple sequence alignment and phylogenetic analysis of the coat protein gene sequence amplified by reverse transcription-polymerase chain reaction. The cp gene contained 819 nucleotides potentially coding for 273 amino acids. The sequence showed 83-99 % nucleotide and 89-99 % amino acid sequence identities with other BYMV isolates/strains and shared maximum identity with BYMV strain reported from Gladiolus sp. in Japan. This study constitutes the first report of BYMV occurrence on P. vulgaris in Himachal Pradesh.