BSH-4菌株对黄瓜菌核病的防治作用及其鉴定

 从日光温室黄瓜根际土壤中分离获得1株拮抗细菌菌株BSH-4。采用平板对峙法结合显微镜观察确定BSH-4对黄瓜菌核病病菌具有较强的抑制作用,导致菌丝粗大、弯曲,菌丝体内原生质褐化、聚集,并延迟菌核形成的时间。BSH-4发酵液对离体叶片接种引起的黄瓜菌核病防效为81.6%,盆栽土壤接种防效为68.3%;对田间发病茎秆治愈率为74.4%,明显优于对照药剂菌核净,且对种子出苗率无影响,对瓜苗有促长作用。经形态特性观察,生理生化鉴定及16S rDNA序列分析,初步确定该菌株为短小芽孢杆菌Bacillus pumilus。

Biocontrol of bacterium strain BSH-4 against cucumber sclerotial blight and its identification

An antagonistic bacterium strain BSH-4 was isolated from rhizosphere soil of cucumber in the greenhouse. Dual culture test indicated that the strain was highly inhibitory to Sclerotinia sclerotiorum by making the mycelium swollen and curly, the protoplasm inside brown and concentrated, and the production of sclerotium delayed. Treat with fermentation broth of BSH-4, the disease control efficacy was 81.6% on detached leaves test, and 68.3% on pot trials. And the recovering rate was attained to 74.4% when sclerotial blight infected stems of cucumber was treated in the field. All the efficacies of BSH-4 broth excelled that of dimethachlon fungicide. The fermentation broth of BSH-4 had no impact on seed germination rate, but also promoted the growth of cucumber seedling. Identification by morphological observation, physiological and biochemical determinations, and 16S rDNA sequences analysis showed that the strain was belonged to Bacillus pumilus.