Molecular characterization of monopartite bhendi (Abelmoschus moschatus) yellow vein mosaic virus and screening of wild okra

Bhendi yellow vein mosaic disease (BYVMD) is the most devastating viral disease of okra (Abelmoschus moschatus ssp. moschatus) which affects yield and quality of the produce in India. The causative agent of BYVMD is begomovirus i.e. bhendi yellow vein mosaic virus (BYVMV) having DNA-A molecule along with betasatellite. Present study was carried out during 2019-21 at research farm of ICAR-National Bureau of Plant Genetic Resources, New Delhi to find out the diversity of begomovirus and its satellite nucleotide sequences derived from wild okra infected samples exhibiting conspicuous symptom of BYVMD using PCR-based detection technique on two wild okra symptomatic samples, viz. EC361170 and EC361148. Full length amplification of BYVMV satellite molecule and partial amplification of DNA-A was carried out using PCR and cloning of both randomly selected samples showed the presence of monopartite BYVMV. In both samples, presence of DNA-A molecule, betasatellite and alphasatellite were noticed. Two year (kharif 2019 and 2021) field screening of 10 accessions of wild okra (Abelmoschus moschatus ssp. moschatus) was carried out at ICAR-NBPGR, New Delhi. Out of 10 accessions, viz. EC360586, EC360794, EC360830, EC360900, EC359730, EC359836, EC359870, EC360351, EC361111 and EC361171 screened, 4 accessions, viz. EC360794, EC360586, EC360830 and EC361171 showed resistant (R) reaction during both the seasons against BYVMD. This is the first study which showed the presence of alpha-satellite molecule of BYVMV from New Delhi region in wild okra along with its resistance source.