CHARACTERIZATION OF A POTHOS (SCINDAPSUS-AUREUS) VIRUS WITH UNUSUAL PROPERTIES

A virus for which the name of pothos latent virus (PoLV) is proposed, was isolated by inoculation of sap from symptomless plants of Scindaps us aureus. PoLV had isometric particles c. 30 nm in diameter, a monopa rtite genome consisting of a non polyadenylated, single-stranded RNA m olecule c. 4,300 nucleotides in length, consituting c. 17% of the part icle weight, and a single type of coat protein subunit with a M(r) of c. 40,000 Daltons. The biological properties (host range reactions) of PoLV resembled those of Tombusviridae for it infected most of the art ificial hosts locally, inducing symptoms recalling those elicited by s everal species of the above family. Like tombus- and carmoviruses, PoL V had two subgenomic RNAs which, in size from those of both genera. Th e dsRNA pattern was also distinctly different. Cytopathological featur es recalled those of tombusviruses except for the lack of multivesicul ar inclusion bodies. PoLV was serologically related to, but distinct f rom two Carmovirus (i.e., galinsoga mosaic and Ahlum waterborne viruse s) and three Tombusvirus species (i.e., eggplant mottled crinkle, Sikt e waterborne and Lato river viruses). Thus, PoLV had properties somewh at intermediate between those of Tombusvirus and Carmovirus genera but bridged the two taxa through the serological relationship with some o f their species. The taxonomic position of PoLV is still undetermined. It must await the results of molecular investigations now underway.