DETECTION AND PHYLOGENETIC RELATIONSHIP OF PAPAYA RINGSPOT VIRUSP IN PAKISTAN
S. Naseem, A. Roofi, Y. Zafar, F.Y. Hafeez
Four commercial papaya orchards in the Sindh province of Pakistan were surveyed for the presence of Papaya ringspot virus (PRSV) in February and May of 2012. Leaf samples with mottling, yellowing and dark streaking were collected from trees with fruits showing concentric C-shaped rings and tested by ELISA with virus-specific antibodies. Results showed that 70 samples tested positive to PRSV, nine of which were characterized by RTPCR using primers designed in the sequence encoding the nuclear inclusion b (NIb) and the coat protein (CP) genes. Phylogenetic analyses of the partial coat protein sequence showed a close relationship of the isolates from Pakistan to one other and to an isolate from India (99% identity) but a relative divergence with other isolates from different geographical locations. This is the first report of PRSV on papaya in Pakistan.