Rhizoctonia cerealis anastomosis group GAG-1, the common pathogen of wheat, barley and sugar beet

Isuluies of <i>Rhizoctonia cerealis</i> anastomosis group GAG-1 were obtained from sharp eyespot lesions on wheat and on barley culms and from diseased sugar beet seedlings. Isolates of <i>R. cerealis</i> were collected from a fields with crop rotation experiments: sugar beet-spring wheat-winter barley. In pathogenicity tests isolates of <i>R. cerealis</i> from sugar beet seedlings and from sharp eyespot lesions on wheat and barley were pathogenic to these crops. Isolates of <i>R. cerealis</i> from sharp eyespot lesions on wheat and barley caused severe damping-ofTof sugar beet. Isolates of <i>R. cerealis</i> from sugar beet seedlings also caused symptoms of sharp eyespot on wheat and barley. None of the wheat and barley isolates of <i>R. cerealis</i> tested caused root-rot on wheat or barley seedlings. Isolates of <i>R. cerealis</i> obtained from diseased plants of wheat, barley and sugar beet were similar in morphology of cultures and anastomosed with GAG-1 tester isolate. The relatinoship between anastomosis. colony characters, growth rate, hyphal diameter and pathogenicity of AG-4. AG-2-2 and AG-5 isolates obtained together with <i>R. cerealis</i> from diseased plants were also investigated.