蚯蚓粪中黄瓜枯萎病菌拮抗细菌的筛选及鉴定

Screening and Identification of Antagonistic Bacterial Strains against Fusarium oxysporum f. sp. cucumerinum in Earthworm Excrement

摘要:

采用稀释平板法,从新鲜蚯蚓粪中分离到374株细菌。筛选出对黄瓜枯萎病菌有拮抗活性的菌株28株,其中以D2的抑菌效果最好,抑菌直径达28.28 mm,且抑菌效果稳定。利用菌体形态和菌落特征观察、生理生化试验和16S rDNA序列同源性分析,对抑菌效果良好的菌株进行分类鉴定,D2的分子生物学鉴定中,得到目的片段大小为1 462 bp,并结合其形态及生理生化特征结果表明该菌株为洋葱伯克霍尔德菌(Burkholderia cenocepacia)。

Abstract:

A total number of 374 bacterial strains were isolated from fresh earthworm excrement by tube dilution assay. The result of plate test showed that 28 strains had antagonistic activity against Fusarium oxysporum f. sp. cucumerinum. According to the results of the suppression assay, strain D2 was selected as the best one. The inhibiting diameter was 28.28 mm and the inhibitory effect is stable. The mycelium shape, colony characteristic observation, a series of physiological and biochemistry experiments and determination of the sequence of 16 S rDNA of the D2 had been done. Identification of molecular biology of D2 obtained the target fragment sized 1 462 bp. Combined with its morphological and physiological and biochemical characteristics, the results showed that the strain was Burkholderia cenocepacia.