Mycoviruses (ancient Greek μύκης mykes: fungus and Latin virus) are viruses that infect fungi. The majority of mycoviruses have double-stranded RNA (dsRNA) genomes and isometric particles, but approximately 30% have positive sense, single-stranded RNA (+ssRNA) genomes. To be a true mycovirus, they must demonstrate an ability to be transmitted... Found on http://en.wikipedia.org/wiki/Mycovirus