拮抗油菜菌核病菌的荧光假单胞杆菌的分离与筛选

2003—2005年,在上海市郊采集常见作物的根际土壤样品,经分离和纯化后共得到254个产荧光的细菌菌株。采用平板对峙培养法测定这些菌株对油菜菌核病菌的拮抗效果,结果从这254个菌株中筛选出了一个高效菌株P13。试验表明,它对菌核病菌的生长具有较强的拮抗能力,同时还发现其对多种常见的植物病原真菌具有广谱拮抗作用。通过显微观察发现,P13菌株可致使油菜菌核病菌菌丝生长形态异常,出现菌丝变形、菌丝壁溃解、原生质浓缩及外渗等异常现象,还可在一定程度上抑制菌核的形成。经电镜观察、培养物特征和一系列的生理生化实验鉴定,可初步确定P13菌株为产荧光假单胞杆菌属中的荧光假单胞杆菌。

Preliminary Studies on Isolation and Screening of Fluorescent Pseudomonas spp. for Biocontrol Sclerotinia Sclerotiorum

254 strains were isolated and purified from the soil samples, which were collected from rhizosphere of the crop in the suburban districts of Shanghai from 2003 to 2005. One strain of P13 was screened out from 254 isolates, which expressed stronger antagonistic effects on Sclerotinia sclerotiorum trough dual culture method. Besides, it could also inhibit some other pathogens of agricultural importance with various extents. Microscopically observed, P13 could induce deformed growth of hyphae of Sclerotinia sclerotiorum, including twist of hyphae, necrosis of the hyphal wall, concentration and leakage of the cytoplasma, and inhibit the formation of sclerotium. Through EM (Electron Microscope) observation, colony analysis and a series of physiological and biochemical experiments, this strain was identified as Pseudomonas fluorescent.