Protoplast-regenerated cultures derived from mycelia of cereal-infecting field isolates of Rhizoctonia solani exhibited major variations in cultural morphology and in pathogenicity. Each field isolate yielded three or four distinct morphological types of protoplast cultures. The presence of the new morphological phenotypes was attributed to the selection of homokaryons arising from protoplasts with single nuclei. Highly pathogenic field isolates produced protoplast cultures with higher virulence than those from weakly virulent pathogenic isolates, and homokaryotic strains were generally less pathogenic than the parental field isolate.
Yang, H. A., Jumei Zhou, N. V., Sivasithamparam, K., & O'Brien, P. A. (1994). Variations in culture morphology and pathogenicity among protoplast-regenerated strains. FEMS Microbiology Letters, 115, 83-86. https://doi.org/10.1016/0378-1097(94)90465-0