烟草赤星病生防菌的分离与鉴定

Isolation and Identification of Biocontrol Bacteria of Tobacco Brown Spot Disease

从连作障碍较严重的烟草根际土壤中分离出49株细菌活体纯培养物,依次编号为HHHB1~HHHB49,并筛选出对烟草赤星病病原菌(Alternaria alternate)具有拮抗活性的菌株HHHB7和HHHB19,二者抑菌圈直径分别为5、23 mm。二者初步定性为具有生防活性。多相鉴定结果表明,活性最强的菌株HHHB19隶属于假单胞菌属(Pseudomonas),暂定名Pseudomonas sp. HHHB19。盆栽试验证实,HHHB19菌株悬液叶面喷雾混合处理对烟草赤星病不同发病阶段均表现出一定的防治效果,其中喷施14 d后防治效果达61.83%。菌株HHHB19可作为良好的生防菌备用资源。

A total of 49 strains of live pure cultures were isolated from tobacco rhizosphere soil with serious continuous cropping obstacles, which were numbered from HHHB1 to HHHB49, respectively, and the strains of HHHB7 and HHHB19 with antagonistic activity against Alternaria alternate were screened out. The diameters of bacteriostatic circles of the two strains were 5 mm and 23 mm, respectively. The two strains were preliminarily characterized as having biocontrol activity. The results of polyphasic identification showed that the most active strain(HHHB19) belonged to the genus of Pseudomonas, and its temporary name was Pseudomonas sp. HHHB19. Pot experiment confirmed that the mixed treatment of HHHB19 strain suspension foliar spray showed certain control effects against tobacco brown spot disease at different stages, and the control effect reached 61.83% after 14 days. HHHB19 strain can be used as a good reserve resource for biocontrol bacteria.