ABSTRACT
The fungal vectors are all obligate parasites which inhabit the roots of plants; some are pathogens in their own right, whereas others are avirulent root parasites. All the proven vectors are lower fungi, Olpidium spp, in the Chytridiales and Polymyxa and Spongospora spp. in the Plasmodiophorales. The discovery of fungal double-stranded ribonucleic acid (dsRNA) interferon inducers and viruses ofPenicillium and Aspergillus spp. had a major impact on fungal virology. It was realized that fungal viruses were probably much more common than had been understood hitherto and many investigators were stimulated to look for viruses in the fungi in which they were interested. Rigid rod-shaped virus-like particles (VLPs) have been described in several species in the Ascomycotina, Basidiomycotina, and Deuteromycotina and are probably widespread in the fungi. The rigid rod VLPs found in fungi each appear to consist of one particle size and hence might be expected to have an undivided genome.
