马铃薯黑痣病生防菌的筛选鉴定及生长条件研究

Isolation,Identification and Growth Condition of Antagonistic Strains Against Potato Black Scurf

采用稀释平板法,从马铃薯根际土壤中筛选到1株对马铃薯黑痣病病原菌立枯丝核菌(Rhizoctonia solani)有良好拮抗效果的生防菌株QHZ-M1,抑菌率达到59.8%;通过生理生化和16S rDNA鉴定,QHZ-M1与芽孢杆菌属(Bacillus)同源性高达99%,且与B.axarquiensis CR-119亲缘关系最近,由此将其鉴定为芽孢杆菌Bacillus axarquiensis。对其生长条件进行了研究,结果表明,菌株QHZ-M1的生长速率较快,接种20 h后就进入稳定期,其生长最适温度为37℃,最适pH 8,最适盐度<25 g/L,最适碳源和氮源分别为蔗糖和酵母浸粉。QHZ-M1对马铃薯黑痣病具有较好的防治效果,具有作为生防制剂的潜力。

A bio-control strain(QHZ-M1) with good antagonistic activity against Rhizoctonia solani of potato black scurf pathogenic bacteria was filtrated from potato rhizosphere soil by plate dilution method. Its inhibition percentage reached59.8%. Based on the physiological and biochemical characteristics, and 16 s r DNA identification, QHZ-M1 had 99%homology with Bacillus and had a close relationship with B. axarquiensis CR-119. Thus, it was identified as B. axarquiensis.Growth conditions of QHZ-M1 were studied and the results showed that the strain growth rate was relatively fast, and reached a stable period after 20 h. The optimal temperature for the growth was 37 ℃, the optimal p H was 8, the optimal salinity was < 25 g/L, and the optimal carbon and nitrogen source was sucrose and yeast extract powder, respectively.QHZ-M1 has good control effect on potato black scurf disease and potential as bio-control agent.