一种野生大豆根际土壤细菌的分离及其防治大豆病害的研究

Isolation of a Bacteria from Wild Soybean Rhizosphere Soil and Its Function to Control Soybean Diseases

为筛选拮抗大豆根腐病的土壤微生物,以邻苯二甲酸为唯一碳源培养基,从野生大豆根际土壤中分离获得1株细菌,命名为HK26-21。通过平皿接种以及16s rDNA序列扩增,根据其生理生化特征和16s rDNA(GenBankAccession No.EF032879)序列相似性分析,将该菌株鉴定为芽孢杆菌属(Bacillus)。通过单因素试验法确定了最佳降解条件:温度为25℃,pH为7.0,降解速率与接种量呈正相关。平皿微生物对峙试验表明菌株可拮抗大豆菌尖孢镰刀菌和立枯丝核菌。初步认为所分离野生大豆根际芽孢杆菌HK26-21可以缓解大豆连作障碍。

Through screening cdaphon resisting soybean root rot, one bacterial strain was isolated from wild soybean rhizosphere in medium with phthalate as only carbonaceous organic compound. It could digest phthalate and was named HK26- 21. Through plate inoculation and 16s rDNA sequence amplification,it was showed that HK26-21 was Bacillus according to physiology-biochemistry characteristics and the similarity of 16s rDNA analysis. Through single factor test, the optimal digesting conditions were： temperature 25 ℃, pH 7.0. Digesting rate had positive correlation with the amount of inoculums. Test of colony standoff in plate proved the bacterium could resist soybean pathogenic fungi （ Fusarium oxysporum and Rhizoctonia solani）. It was considered that the isolated bacterium from wild soybean rhizosphere could have biological control efficacy against pathogens of soybean root rot.