陕西棉花黄萎菌落叶型及非落叶型的鉴定

应用落叶型和非落叶型大丽轮枝菌特异性引物D-1/D-2和ND-1/ND-2,对从陕西采集的67株菌株、矿物油室温保藏的24株菌株和中国农业科学院棉花所提供的5个大丽轮枝菌进行落叶型与非落叶型分子鉴定,以明确陕西是否存在落叶型菌株,掌握不同致病类型菌株的出现频率。结果表明,67株陕西菌株中有21株落叶型菌株,46株非落叶型菌株,落叶型菌株的比率为31.3%;其余29株菌株中14株为非落叶型菌株,5株为落叶型菌株,9株未产生特异性条带,1株用两对引物均可扩增出特异性条带。采用无底塑钵菌液浇根法接种冀棉11进行致病性测定,以了解落叶型菌株和非落叶型菌株致病力的差异。结果显示,21株落叶型菌株的平均病情指数为40.5,是19株非落叶型菌株病情指数(17.9)的2.3倍。

Identification of Defoliating and Nondefoliating Pathotype of Verticillium dahliae Isolated from Shaanxi

In order to know whether there is defoliating pathotype Verticillium dahliae or not in Shaanxi and analysis the frequency of the different pathtypes of Verticillium dahliae, 67 strains isolated from Shaanxi,and 16 strains stored in mineral oil at room temperature, and 5 Verticillium dahliae strains provided by Cotton Research Institute, Chinese Academy of Agriculture Sciences were identified by specific primer D-1/D-2 and ND-1/ND-2 for defoliation and nondefoliation, respectively. The results indicated that there were 21 defoliating isolates and 46 nondefolating strains among 67 strains isolated from Shaanxi. The percentage of defoliating isolates was 31.3%. Among the other 29 strains, 14 were nondefoliating strains, 5 were defoliating strains, 9 did not generate specific fragment, and one generated both fragments. In order to analysis the difference of pathogenicity between defoliating and nondefoliating strains, 40 strains were chosen to conduct the pathogenicity test. The average of disease index of cotton inoculated with defoliating and nondefoliating strains were 40.5 and 17.9, respectively. The average disease index of defoliating strains was nearly 2.3 times of that of nondefoliating strains.