Diverse and recombinant begomoviruses and various satellites are associated with Bhendi yellow vein mosaic disease of okra in India

Bhendi/Okra, a common vegetable in the Indian subcontinent, is highly susceptible to the viral disease Bhendi yellow vein mosaic disease (BYVMD), resulting in considerable yield loss to the crop. As a first step towards formulating novel strategies against BYVMD, the identities of the viruses and associated satellite molecules were investigated in BYVMD-affected okra leaf samples taken from ten widely separated locations in India. The amplified nucleotide sequence representing the viral coat protein from the samples indicated the presence of the begomoviruses Bhendi yellow vein mosaic virus (BYVMV) in seven and Mesta yellow vein mosaic virus (MeYVMV) in three samples. Subsequent analysis of the full-length viral sequences revealed the presence of a recombinant viral DNA, having MeYVMV and Malvastrum yellow vein Yunnan virus (MYVYNV), a virus not previously reported from India, as parents. Betasatellite sequences were very similar to previous reports. Analysis of the symptomatic samples by Rolling circle amplification showed, in addition to BYVMV-like sequences, begomoviral sequences reported earlier from cotton and mint and alphasatellites reported previously from cotton and Cyamopsis tetragonoloba were also present. This study indicated that the diversity of begomoviruses and satellites associated with BYVMD is much higher than previously thought.