山东烟草白绢病病原鉴定及室内防治药剂筛选

Identification and Pharmaceutical Screening on Plate of Sclerotium rolfsii Sacc. Causing Southern Blight on Tobacco

摘要: 在实验室对采自山东费县费城烟株根部的白色菌丝进行分离、纯化,编号为FBJ,对其致病性、形态特征观察、生物学特性及防治药剂筛选进行了初步研究。结果表明,FBJ对烟草具有致病性,经形态特征及18S rDNA序列分析,FBJ为半知菌亚门,丝孢纲,无孢目,小菌核属的齐整小核菌(Sclerotium rolfsii Sacc.)能引起烟草白绢病。FBJ白绢病菌适合在偏碱性条件下生长;菌丝和菌核致死温度为50 ℃处理10 min;通过室内药剂筛选,70%代森锰锌可湿性粉剂对FBJ病菌菌丝生长和菌核萌发的抑制效果较好。

Abstract: The morphology, biological characteristics, 18SrDNA and fungicide screening of the pathogen isolated from the root of tobacco from Feixian in Shandong province were studied. The results showed that pathogen of FBJ had pathogenicity of tobacco. Through morphological characteristics and 18S rDNA sequence analysis, FBJ was Sclerotium rolfsii Sacc. It could cause southern blight on tobacco. Biological characteristics displayed that the pathogen of FBJ grew well at the pH range of 5.0-10.0, with the optimal pH of 9.0. Hypha and sclerotia viability were completely lost when hyphal agar plugs and sclerotia incubated at 50℃ 10 minutes. Fungicide testing on PDA plates revealed that 70% Mancozeb showed the greatest inhibition of hyphal growth and sclerotia germination of S. rolfsii.