Study on anastomosis groups and their pathogenicity of Rhizoctonia solani isolated from alfalfa in Xinjiang

155 strains of Rhizoctonia were isolated from diseased plant and soil in alfalfa (Medicago sativa) fields in Xinjiang, China. 126 strains of them were identified as R.solani. The research reported the composition and pathogenicity in anastomosis groups of R.solani in alfalfa. According to the discriminative results of anastomosis groups(AGs), these strains of R. solani were categorized as the following four anastomosis groups(AGs): AG1, AG2, AG4, AG5. Their occurrence frequency in order was 11.2%、46.6%、6.1% and 36.1%. AG2 and AG5 which have higher frequency of separation are the edge of anastomosis groups. The testing results showed that pathogenicity of each anastomosis groups were significantly different, and AG2 had the strongest pathogenicity.