Detection and partial genome sequence of a new umbra-like virus of papaya discovered in Ecuador

Sequencing of cDNA synthesized from double-stranded RNA (dsRNA) from papaya leaves revealed the presence of a putative new virus with homology to genomes of several members of the genus Umbravirus. A wide survey showed that the virus was present in two out of three papaya producing provinces in Ecuador included in this study. The virus was found in up to 31 % of symptomatic trees co-infected with Papaya ringspot virus (PRSV) compared to 2 % in symptomless PRSV-free plants. Mechanical and aphid inoculations failed to transmit the virus under controlled conditions. The virus was not transmitted through seeds. The presence of a luteovirus, commonly associated with umbraviruses, was not confirmed in plants infected with the new virus using universal luteovirus primers.