Identification and characterization of Papaya ring spot virus - W isolate on bottlegourd in Telangana state of India

Abstract

Incidence of Papaya ringspot virus (PRSV) was noticed in the F2 population of bottlegourd hybrid, “MGH 4-Waradâ€, grown in the experimental farm of Vegetable Research Station, Sri Konda Laxman Horticultural University, Rajendranagar, Hyderabad during 2013-2014. The disease was diagnosed and confi rmed by Direct antigen coated Enzyme linked immunosorbent assay (DAC-ELISA). Pathogenicity test resulted in symptom expression in watermelon and bottlegourd seedlings, but not in papaya indicating that the virus isolate under study is a cucurbit isolate (W) and not a papaya isolate (P) as it failed to infect papaya. Molecular characterization of the virus isolate revealed the presence of amplicon of ~770 bp in the infected samples, while none in healthy sample. The test isolate was identified as a potyvirus, namely PRSV-Watermelon strain and is closely related to PRSV-W isolates of watermelon and pumpkin from Karnataka with 98.7 and 96.6 per cent identity, respectively and cucumber isolate from Tamilnadu with 96.3 per cent identity.