DNA Base Sequence Homology in Rhizoctonia solani Kühn

VII. Genetic Relatedness between AG-BI and Other Anastomosis Groups

Abstract

DNA base sequence homology between isolates of AG-BI and other anastomosis groups in Rhizoctonia solani was determined by DNA-DNA reassociation kinetics. A comparatively high homology was observed between AG-BI and AG-2. AG-BI isolates showed 36.1 to 48.0% homology with isolate of AG-2-1 and 34.0 to 46.4% homology with isolates of AG-2-2. While, AG-BI isolates showed 18.7 to 30.2% homology with isolates in AG-3 and AG-6, but consistently low homology (0 to 14.4%) with isolates in the other anastomosis groups. These results suggest that AG-BI and AG-2 should not be considered as separate groups. The phylogenetical relationship between AG-BI and the groups of AG-2, AG-3 and AG-6 is discussed.