Anastomosis Grouping and Variation in Virulence Among Isolates ofRhizoctonia solaniAssociated with Dry Bean and Soybean in Ohio and Zaire

Anastomosis groupings (AG) of 290 Rhizoctonia solani isolates from diseased dry bean (Phaseolus vulgaris) and soybean (Glycine max) roots and/or hypocotyls and foliage in Ohio (the United States) and Zaire (Africa) were determined. Virulence of 60 isolates, representing 12 isolates each from one of five origin/host/anastomosis-group categories, was studied on dry bean cv. Great Northern and soybean cv. Williams. Variation in virulence was assessed by inoculating roots, hypocotyls, and leaves. Ohio dry bean and soybean hypocotyl/root isolates were AG-2-2 IIIB, Zaire dry bean hypocotyl/root isolates were AG-4, and Zaire dry bean and soybean foliar isolates were AG-1 IB []