拮抗菌Ata 28对烟草赤星病菌的抑制及种类鉴定

从烟草叶片上分离到的细菌Ata28经鉴定为枯草芽孢杆菌（Bacillus subtilis），通过平板对峙培养，测定其对不同致病力的烟草赤星病菌（Affernaria alternata （Fries）Keissler）均有拮抗作用，抑菌带的宽度达8．4mm；在温室中进一步进行盆栽控病试验，防治效果为75.8％．无菌滤液试验表明，拮抗菌Ata28的无菌滤液在一定浓度范围内均能有效地抑制赤星病菌菌丝生长，减少孢子萌发，且浓度越高，抑制能力越强．

Identification of the Antagonistic Bacterium Ata 28 and its Inhibition of Tobacco Brown Spot

Ata 28, a bacterium strain with biocontrol capacity, was isolated from tobacco leaf surface and identified as Bacillus subtilis. In pairing culture on PDA, Ata 28 showed good antagonistic effects on 4 strains of different virulent Alternaria alternata, the pathogen of tobacco brown spot, with an inhibition zone diameter of 8.4 mm. In a subsequent greenhouse experiment, the suspension liquid of Ata 28 was used to inoculate the leaves of tobacco variety K236. The bacterial preparations from Ata 28 were shown to be effective in reducing the incidence of tobacco brown spot, the control efficiency being 75.8%. The results from culture filtrate showed that Ata 28 was effective in inhibiting mycelium growth and reducing spore germination of A. alternata.