油菜菌核病菌拮抗海洋细菌GM-1菌株的种类鉴定及抑菌作用研究

从连云港海域分离到1株对油菜菌核病菌有显著抑制作用的海洋细菌菌株GM-1,对其进行种类鉴定、抗菌作用测定及盆栽防病效果测定.通过形态特征观察、生理生化试验及16SrDNA序列、gyrB基因序列分析,将该菌株鉴定为芽胞杆菌属(Bacillus)的解淀粉芽胞杆菌(Bacillus amylolique faciens).抑菌作用测定结果表明:GMl菌株和无菌发酵液对油菜菌核病菌菌丝的生长具有明显的抑制作用,培养7d的抑菌带宽度分别达到30mm和16mm,GM-1菌株和无菌发酵液对菌丝细胞结构有明显的破坏作用,导致菌丝细胞壁变厚、膨大；同时对菌核的萌发有明显的抑制作用,菌液较无菌发酵液的抑制作用更显著.盆栽防病效果测定表明:该菌株菌液对油菜菌核病具有明显的防治作用,防治效果达68％,同时能够促进油菜种子萌发,显示出良好的开发应用前景.

Identification and inhibitory effects of the marine bacterial strain GM-1 antagonistic to Sclerotinia sclerotiorum

The strain GM-1, isolated from marine area of Lianyungang, was a highly efficient antifungal strain against Sclerotinia sclerotiorum. This study aimed to identify its species, determine its inhibition effect and conduct pot experiments. The isolate was identified as Bacillus amyloliquefaciens by means of phenotypic observation, physiological and biochemical index determination and 16S rDNA and gyrB sequence analysis. The results indicated that fermentations and culture filtrate of GM-1 had obvious antimicrobial effects against S. sclerotiorum. The inhibition zones were 30 mm and 16 mm, respectively, after 7 days of culture. GM-1 induced alteration on hyphal morphology of S.sclerotiorum, such as distortion and deformation. Moreover, its fermentations and culture filtrate inhibited the germination of sclerotia, and the inhibition by fermentations was more significant than culture filtrate. Pot experiments indicated that the strain suppressed rape sclertiniose, with a control efficiency of 68%. It could promote seed germination. These data suggested that the strain GM-1 should be useful in biological control of S.sclerotiorum.