黄瓜棒孢叶斑病是近年来危害严重的黄瓜病害之一,严重时可导致黄瓜大面积减产.菌株ZF2是本实验室从黄瓜植株体内分离筛选得到的一株对多主棒孢菌有显著抑制效果的生防细菌.经生理生化测定、Biolog测定和多基因系统发育树综合分析,鉴定菌株ZF2为贝莱斯芽胞杆菌.酶学试验和光学显微观察结果表明,菌株ZF2在代谢过程中产生蛋白酶和纤维素酶,使多主棒孢菌菌丝生长受到抑制并形成连续的椭圆型膨胀,抑制率达60.10％.利用平板对峙法和双层培养法证明菌株ZF2具有广谱拮抗作用,对6种病原真菌和7种病原细菌具有显著拮抗效果.黄瓜棒孢叶斑病的防效测定结果显示,接种菌株ZF2的黄瓜发病明显减轻,防效为90.81％.综上,菌株ZF2生防性状优良,在植物病害生物防治中有一定应用潜力.%In recent years, Corynespora leaf spot caused by Corynespora cassiicola is one of the most destructive diseases of cucumber (Cucumis sativus), causing significant yield losses to cucumber production. A biocontrol bacterium ZF2 isolated from the cucumber plants had significant inhibitory effect on C. cassiicola. The strain ZF2 was identified as Bacillus velezensis based on 16 S r DNA sequence analysis, physiological and biochemical characteristics, biolog analysis, and multilocus sequence analysis. Enzymatic test and microscopic observation showed that strain ZF2 could produce protease and cellulase during the metabo lic process, which caused mycelium malformation and formed continuous elliptic expansion. The inhibition rate on mycelial growth was 60.10％. The antibacterial and antifungal activity of strain ZF2 was tested by double-layer culture method and plate confrontation method, respectively. The results showed that ZF2 exhibited significant and broad inhibitory spectrum against six pathogenic fungi and seven pathogenic bacteria. Meanwhile, the control effect of strain ZF2 on Corynespora leaf spot disease was examined using potted plant in greenhouse. The results indicated that the disease incidence of cucumber inoculated with strain ZF2 was significantly reduced and the control eff icacy was 90.81％. In summary, the strain ZF2 has excellent biocontrol characteristics and potential in biocontrol of plant diseases.
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