摘要
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。
In 1989 -1990, winter wheat plants infected with sharp eyespot were sampled from 24 counties of Jiangsu Province. Thirty-nine CAG1 isolates of Rhizoctonia cerealis Vander Ho-even were isolated and examined in terms of colony morphology, mycelial growth rate at 20C and 30C,, mycelial growth rate on potato-sucroce-agar medium amended with CuSO4 (0. 5 g/1) or LiCl (2 g/1), sensitivity to triadimefon (effective concentration for 50% inhibition of linear growth), percentage of diseased wheat seedlings and length of lesions on the sheaths of adult wheat plants caused by the isolates. Significant differences in these properties were found among the 39 isolates of R. cerealis . By fuzzy progressive clustering, the 39 isolates were classified into three groups in rough (resemblance coefficient>0. 7). The three groups differed from each other in the examined properties,especially in disease incidence in the seedlings. This indicates that there may be pathogenicity differentiation among the CAGi isolates of R. cerealis .
出处
《江苏农业学报》
CSCD
1992年第3期30-35,共6页
Jiangsu Journal of Agricultural Sciences
基金
江苏省麦类纹枯病综防研究课题内容之一
关键词
致病力
分化
禾谷丝核菌
小麦
Pathogenicity differentiation
CAG1 isolates
Rhizoctonia cerealis
Wheat
