Transmissibility of viral double-stranded RNA between strains of the violet root rot fungus Helicobasidium mompa and the potential for viral dsRNA infection to this fungus using monokaryotic strains

Abstract

To examine the potential of a method of doublestranded (ds) RNA infection to Helicobasidium mompa, the transmissibility of dsRNA between strains of this fungus was investigated. Strain V70 was used as a dsRNA donor. The dsRNA recipients were six strains that were mycelially incompatible with V70, plus two monokaryotic strains. Random amplified polymorphic DNA analysis suggested that the mycelially incompatible strains were genetically different mutually; however, the analysis also suggested that V70 was genetically homogeneous with the two monokaryotic strains. When V70 was paired with either of the mycelially incompatible strains, the dsRNAs did not transmit to the recipients at all. When V70 was paired with the two monokaryotic strains, the dsRNAs were transmitted to the monokaryotic strains. The two monokaryotic strains, which had acquired dsRNAs from V70 in the previous experiment, were used as new dsRNA donors in a next experiment so that we could investigate dsRNA transmission from these monokaryotic strains to the six strains used in the previous experiment. One of the monokaryotic strains permitted dsRNA transmission to two of the six recipients. We conclude that we can infect genetically different strains of H. mompa with dsRNA using the monokaryotic strains.