人参灰霉病拮抗细菌的筛选及鉴定

为获取对灰葡萄孢Botrytis cinerea Pers.ex Fr.防效优良的菌株,采用滤纸片法和牛津杯法从105株菌株中筛选出7株拮抗性良好的菌株,采用平板对峙法对抑菌效果较好的菌株SZ-35进行抑菌谱测定,采用盆栽法研究其对人参灰霉病的防效及在人参体内的定殖能力,并通过形态学、生理生化特征、16S rDNA及gyrB基因测序确立其分类地位。结果显示,菌株SZ-35对灰葡萄孢的抑制作用最强,抑菌率和抑菌带宽分别为86.53%和12.20 mm,且具有广谱抑菌能力;菌株SZ-35可有效定殖于人参体内,对人参灰霉病的防效达76.42%,显著高于70%代森锰锌可湿性粉剂;通过形态特征、生理生化特征观察,以及16S rDNA及gyrB同源性序列对比分析,鉴定菌株SZ-35为解淀粉芽胞杆菌Bacillus amyloliquefaciens(GenBank登录号为KC511113)。研究表明,解淀粉芽胞杆菌SZ-35对灰葡萄孢具有良好的抑菌能力,且在人参中的定殖能力较好。

Isolation and characterization of antagonistic bacteria against ginseng grey mould

To obtain more effective antagonistic bacteria against Botrytis cinerea Pers. ex Fr., seven antagonistic bacteria strains were screened from 105 bacterial strains isolated from ginseng rhizosphere soils by using the Kirby-Bauer disk diffusion and the assay by Oxford cup plate. The antibacterial spectrum of strain SZ-35 was examined using flat-stand method. The colonization ability and control efficiency of strain SZ-35 against pray mold of ginseng were evaluated by pot experiment, and also the taxonomic status of strain SZ-35 was identified using morphology, physiological and biochemical characteristics, 16S rDNA and gyrB sequences. The results showed that the inhibitory effect of strain SZ-35 against B.cinerea was the highest among all strains and had broad-spectrum antibacterial function. The inhibition rate and inhibition zone were 86.53% and 12.20 mm. The strain SZ-35 could colony effectively in the root, stem and leaves of ginseng. The control efficacy of strain SZ-35 against pray mold of ginseng with 76.42% was higher than that of 70% mancozeb WP fungicide treatment. According to the morphology, physiological and biochemical characteristics, 16S rDNA and gyrB sequences, strain SZ-35 was identified as Bacillus amyloliquefaciens (GenBank accession no. KC511113). The results indicated that strain SZ-35 could successfully colony in the ginseng and effectively control B. cinerea.