Abstract
DNA base sequence homology among AG-1 isolates of Rhizoctonia solani was investigated on the basis of DNA-DNA reassociation kinetics, and the genetic relationship among pathological types was examined. High values of DNA homology (range from 98.0 to 100.3%) were observed among isolates of the sasakii type (IA). There was also high homology among isolates of the web-blight type (IB) (range from 95.7 to 99.4%). While, comparatively low values of DNA homology were observed between isolates of both types (range from 49.9 to 55.9%). These results indicated that each pathological type in AG-1 is genetically homogenous, but both types are genetically divergent from each other.
