Characterization of potato yellow mosaic virus as a geminivirus with a bipartite genome

A whitefly-transmitted virus from Venezuela, potato yellow mosaic virus, has been propagated, isolated and characterized as a member of the Geminivirus group. The virus was transmitted to several species of Nicotiana and to Petunia hybrida by mechanical inoculation, and to potato and tomato plants by grafting. Purified virus possessed typical geminate particle morphology and encapsidated both genomic and subgenomic species consisting of single-stranded DNA. The genome of the virus was cloned into both bacteriophage and plasmid vectors following restriction of supercoiled double-stranded DNA species isolated from infected plant extracts. Two distinct classes of cloned DNA were generated, both about 2,500-2,600 base pairs in length and designated A and B, which when inoculated in combination to Nicotiana benthamiana were infectious after excision from the recombinant clones. The subgenomic DNA was shown to be related to DNA B.