大白菜软腐病拮抗菌的筛选、鉴定及其防效研究

为筛选对大白菜软腐病具有较好拮抗效果的生防菌株,采用对峙平板法分别从作物根际土、发酵池以及本实验室菌种库得到6株拮抗性较强的菌株ASR-12、ASR-23、ASR-31、ASR-54、ASR-55、ASR-150。在离体叶柄软腐防效试验中,采用注射接种法获得了拮抗性较强的3株拮抗菌ASR-12、ASR-23和ASR-150,48 h的防效分别达到了87.64%、80.90%和70.79%。温室防效试验的结果表明:菌株ASR-12、ASR-23和ASR-150防治效果分别为59.22%、59.21%和55.00%,显著高于72%农用链霉素可湿性粉剂的防效(39.15%),具有很好应用前景。依据形态、生理生化和分子鉴定,菌株ASR-12被鉴定为解淀粉芽胞杆菌Bacillus amyloliquefaciens。

Screening, identification and control effect of the antibacteriaagainst soft rot of Chinese cabbage

In order to screen the antagonistic strains with good effects on soft rot of Chinese cabbage, a total of 6 strong antagonistic strains, ASR-12, ASR-23, ASR-31, ASR-54, ASR-55 and ASR-150, were isolated from the rhizosphere soil of the crops in the greenhouse, fermentation pool and bacterial bank through confrontation plate culture. Three antagonistic strains, ASR-12, ASR-23 and ASR-150, were selected for soft rot resistance test by petiole injection method of Chinese cabbage in vitro, and their control effects were 87.64%, 80.90% and 70.79%, respectively, in 48 h. The three strains were tested against soft rot in the greenhouse by spraying method, and the results showed that the control effects of the strains ASR-12, ASR-23 and ASR-150 were 59.22%, 59.21% and 55.00%, respectively, significantly better than 72% agricultural streptomycin wettable powders whose effect was 39.15%, indicating they have good application prospect. Based on morphological, physiological and biochemical and molecular identification, the strain ASR-12 was identified as Bacillus amyloliquefaciens.