关防风立枯病病原菌根际拮抗细菌筛选与鉴定

Screening and Identification of the Antagonistic Bacteria against Saposhnikovia divaricata Seedling Damping-off

为筛选出对立枯丝核菌Rhizoctonia solani Kühn具有优良防效的拮抗菌株。本研究从关防风根际土壤中分离纯化出156株细菌,采用平板对峙法测定菌株SC-32和SC-127对立枯丝核菌均有良好拮抗效果,且兼具广谱抑菌能力;抗生素标记法测定菌株SC-32和SC-127接种35 d后在土壤中含菌量仍能保持2.93×10^(7)和7.83×10^(6)CFU/g;通过盆栽试验研究结果表明,菌株SC-32和SC-127对关防风立枯病的防治效果为60.53%和65.89%,高于菌剂和农药处理。通过形态学、生理生化特征、16S rDNA基因序列进行分类学鉴定确定菌株SC-32和SC-127均为贝莱斯芽胞杆菌Bacillus velezensis。

This study aims to discover antagonistic strains with good control effect against Rhizoctonia solani.156 bacterial strains were identified and purified from Saposhnikovia divaricata rhizosphere soil,and both strains SC-32 and SC-127 exhibited good antagonistic effects against R.solani by plate antagonism technique,as well as broad-spectrum antibacterial capacity.35 days post antibiotic labeling inoculation,the quantities of SC-32 and SC-127 remained 2.93×10^(7) and 7.83×10^(6)CFU/g in soil,respectively.Pot experiment revealed that SC-32 and SC-127 had 60.53%and 65.89%control efficacies on S.divaricata seedling damping-off,respectively,which were greater than thiophanate-methyl,Trichoderma harzianum,and Bacillus subtilis.Based on analyses of morphological,physiological,and biochemical properties,as well as the 16S rDNA gene sequence,the strains SC-32 and SC-127 were identified as Bacillus velezensis.