A Transitory Cottony Variant of Rhizoctonia solani from Rice

Abstract

Cultures of single mycelial fragments from the cottony mycelial mass of Rhizoctonia solani occurring on rice plants with sheath blight consisted of a new cottony type and the ordinary type. The new variant reverted to the ordinary type in every case before it covered the petri plate. It was pathogenic to rice plants and the transitory nature of the organism also occurred in the parasitic phase of the life cycle.