具有稻瘟病菌拮抗活性的枯草芽孢杆菌的分离与鉴定

Isolation and Identification of Antagonistic Bacillus subtilis Strain against Magnaporthe grisea

采用梯度稀释分离法,从黄河稻区水稻根际土壤中分离出耐高温芽孢菌722株。通过真菌生长抑制试验,获得具有稻瘟病菌拮抗活性的菌株27株。通过形态学观察和生理生化指标鉴定,获得具有稻瘟病菌拮抗活性的枯草芽孢杆菌疑似菌株7株。挑取其中抑菌活性最强的1株进行16SrDNA鉴定,将其16SrDNA基因序列与GenBank中基因序列进行同源性比较,发现与枯草芽孢杆菌16SrDNA有99%同源性,判定此菌为枯草芽孢杆菌,命名为BS501a。

Seven hundred and twenty-two bacteria strains were isolated from soil samples,which were taken from the rhizosphere of rice near the yellow river,through gradient-dilution separation method.Twenty-seven strains of them showed antagonistic activities against Magnaporthe grisea through fungi growth inhibition method.In the twenty-seven strains seven strains were similar to Bacillus subtilis based on their morphological,physiological and biochemical characteristics.The bacterium which had the strongest antagonistic activity against Magnaporthe grisea was identified via 16S rDNA sequence alignmnet,and found to share 99% similarity with Bacillus subtilis 16S rDNA sequence in Genbank.The strain was designated as Bacillus subtilis strain BS501a.