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1989—1990年从江苏省11个市的24个县采集小麦纹枯病株,分离到属于禾谷丝核菌(Rhizoctonia cerealis vander Hoeven)的CAG_1群菌株39个,研究了各菌株在20℃、30℃下的菌丝生长速率,对Cu~(++)(0.5克/升)和Li~+(2克/升)耐性,成株期和幼苗期的致病力以及对三唑酮的敏感性(EC_(50))。结果表明:江苏省禾谷丝核菌CAG_1群内的菌株间存在明显的变异性,特别是对麦苗的致病力差异极为明显。采用模糊逐步聚类法,39个菌株可分成Ⅰ、Ⅱ、Ⅲ类,各类菌株诱发幼苗发病率的平均值分别为1.2％、45.7％和74.8％,显示同一融合群(CAG_1)菌株间存在致病力分化现象。
From 1989 to 1990, wheat sheath blight strains were collected from 24 counties of 11 cities in Jiangsu Province, and 39 CAG_1 group isolates belonging to Rhizoctonia cerealis vander Hoeven were isolated. The mycelial growth rate at 30 ℃, the resistance to Cu ~ (++) (0.5 g / L) and Li ~ + (2 g / L), the virulence of adult and seedling stage, Sensitivity (EC_ (50)). The results showed that there were obvious variability among strains of CAG_1 of R. cereus in Jiangsu Province, especially for the virulence of wheat seedlings. By means of fuzzy stepwise clustering, 39 isolates were classified into Ⅰ, Ⅱ and Ⅲ, and the average incidences of seedlings induced by various strains were 1.2%, 45.7% and 74.8%, respectively, indicating that there existed between the same fusion group (CAG_1) strains Pathogenicity differentiation phenomenon.