人参内生拮抗细菌分离、鉴定及其对人参菌核病抑菌作用研究

Isolation and identification of endophytic bacteria from Ginseng and its inhibition activity against Sclerotinia ginseng

以人参核盘菌(Sclerotinia ginseng)为靶标,采用抑菌圈法,测定了221株人参内生细菌对其菌丝生长的抑制作用,筛选出3株(Psn52、Psn61、Psn214)抑菌圈大于30 mm的高效拮抗细菌,对其进行了离体防效测定及种类鉴定。Psn52、Psn61、Psn214菌株对人参核盘菌菌丝抑菌率分别为62.72%、61.45%、63.20%。3株无菌发酵液对人参核盘菌菌核萌发抑制效果显著,抑制率分别可达80%、68%、76%。显微镜下观察Psn52、Psn61、Psn214菌株均对人参核盘菌菌丝内含物有明显的溶解作用,导致菌丝变粗、菌丝细胞空洞、原生质分布不均匀。菌株Psn52、Psn61、Psn214无菌发酵液对人参菌核病防治效果明显,防治效果分别达81.25%、75.01%、81.25%。通过培养性状、形态特征、生理生化试验及16Sr DNA同源序列比对分析,将菌株Psn52、Psn61、Psn214鉴定为解淀粉芽孢杆菌(Bacillus amyloliquefaciens)。

Two hundred and twenty one endophytic bacterial strains were isolated from Panax ginseng plants with pathogen target of Sclerotinia ginseng. Among them, 3 strains（Psn52、Psn61、Psn214） with high inhibition efficiency were selected, which showed more than 30 mm of bacteria inhibition circle, and their controlling efficiency in vitro were tested and species were identified. Bacteria inhibition rate of Psn52、Psn61、Psn214 against S. ginseng hypha growth were62.72%, 61.45%, 63.20% respectively, and their sterile fermentation liquid showed strong bacteria inhibition effect against the germination of Sclerotia with the rates of 80%, 68%, 76%, respectively. By observation with microscope, all the three strains showed significant solution effect to hypha inclusion of S. ginseng and made hypha wider and distribution of cell plasma non-uniform. Efficiency of the sterile fermentation liquid against the disease of Psn52 、Psn61、Psn214 were significant with controlling rates of 81.25%, 75.01%, 81.25% respectively. According to culture characteristic, morphology,physiological and biochemical property and 16 s r DNA sequence analysis, the three strains were identified as Bacillus amyloliquefaciens.