SUMMARY

Two RNA species, and one DNA species, were isolated from subterranean clover red leaf virus (SCRLV) prepared by a modification of previously described methods. 3H-labelled cDNA transcribed from high molecular weight RNA of purified virus was specific for the detection of SCRLV, in that it showed no hybridization with nucleic acids from either healthy plants, or plants infected with the serologically related potato leaf roll virus, but hybridized with homologous RNA and nucleic acids from SCRLV-infected plants of two species. The cDNA detected SCRLV in individuals and groups of the aphid vector, Aulacorthum solani, and the average virus content was greater than 170 pg per aphid. The non-vector, Myzus persicae, contained only trace amounts of SCRLV, a result confirmed by enzyme-linked immunosorbent assay