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为明确土壤拮抗细菌对人参常见病原菌的生防价值,从吉林省抚松县人参根际土壤中分离、纯化获得113株细菌,采用平板对峙法测定菌株的拮抗能力,通过温室盆栽试验研究其在土壤及人参根部的定殖规律,并通过形态、培养特征及16S r DNA序列分析进行分类鉴定。对峙试验结果表明,2株细菌对供试人参病原菌具有良好的拮抗广谱性,且多次验证其抑菌效果稳定。定殖研究结果表明,活性菌株SZ-56与SZ-60的定殖能力均达到显著水平,在土壤中的最大定殖菌量分别为每克土7.51×106CFU和7.28×106CFU,30 d后定殖菌量仍保持在105CFU;21 d后在人参根部的定殖菌量仍保持在每克根105CFU水平。根据形态、培养特征、生理生化指标和16S r DNA序列分析,确定SZ-56为内生芽胞杆菌Bacillus endophyticus,SZ-60为解淀粉芽胞杆菌B.amyloliquefaciens。
In order to clarify the biocontrol value of soil antagonistic bacteria against common pathogens of ginseng, 113 strains of bacteria were isolated and purified from the rhizosphere soils of ginseng in Fusong County, Jilin Province. The antagonistic ability of the strains was tested by plate confrontation method. Soil and ginseng root colonization law, and through the morphological and cultural characteristics and 16S r DNA sequence analysis of classification and identification. Confrontation test results show that the two strains of bacteria on the pathogenic bacteria have a good antagonistic broad-spectrum, and repeatedly confirmed its antimicrobial effect is stable. Colonization results showed that the colonization ability of the active strains SZ-56 and SZ-60 reached a significant level, the maximum colonization amount in the soil was 7.51 × 106CFU and 7.28 × 106CFU per gram soil, respectively, after 30 days The amount of colonizing bacteria remained at 105CFU; after 21 days, the colonizing bacteria in root of ginseng still remained at 105CFU per gram. According to morphological, culturing characteristics, physiological and biochemical indicators and 16S r DNA sequence analysis, SZ-56 was identified as Bacillus endophyticus, SZ-60 was B. amyloliquefaciens.