SRI-LANKAN PASSION-FRUIT MOTTLE VIRUS, A POTYVIRUS INFECTING GOLDEN PASSION-FRUIT IN SRI-LANKA

A sap-transmissible virus, provisionally named Sri Lankan passion fruit mottle virus (SLPFMV), was isolated from Passiflora edulis f. flavicarpa and shown to induce leaf mottling and distortion in that host. The virus infected 23 species in five plant families with systemic infection being common in the Passifloraceae. Chenopodium amaranticolor was a good local lesion host and Passiflora foetida was a useful systemic host for purification. In P. foetida extracts, SLPFMV lost infectivity after 10 min between 70-75-degrees-C, 6-7 days at 20-23-degrees-C and at dilutions of 10(-5)-10(-6). The virus had flexuous, filamentous particles with a normal length of c. 841 nm. Two polypeptides of mol. wt c. 33 200 and 28 700 were detected in purified virus preparations, and a major species of double-stranded RNA (mol. wt 7.0 X 10(6)), was detected in infected plants. Pinwheels, tubular and laminated inclusions were found in ultrathin sections of infected P. edulis f. flavicarpa and cylindrical inclusions were observed in epidermal strips. SLPFMV was transmitted by the aphids Myzus persicae, Aphis spiraecola, A. gossypii and A. craccivora after brief acquisition feeds. SLPFMV reacted with antisera to several potyviruses including passion fruit woodiness virus, passion fruit ringspot virus, potato virus Y and watermelon mosaic virus 2 and thus, apparently, is a member of the potyvirus group.