白菜黑腐病拮抗菌Lysobacter enzymogenes CX03的分离鉴定及生防效果研究

从白菜根际土壤中分离到一株对白菜黑腐病菌具有显著拮抗效果的生防细菌CX03。根据生物学特征、生理生化分析、Biolog测定及多基因系统发育分析，鉴定菌株CX03为产酶溶杆菌Lysobacter enzymogenes。酶学试验结果表明，菌株CX03在代谢过程中产生纤维素酶、蛋白酶和几丁质酶。通过抑菌谱分析，证明菌株CX03具有广谱拮抗作用，对野油菜黄单胞野油菜致病变种、密执安棒杆菌密执安致病变种等5种病原细菌和尖孢镰孢菌、辣椒疫霉菌等4种病原真菌具有显著的拮抗效果。通过盆栽试验结果显示，菌株CX03处理组的白菜黑腐病症状明显减轻，防治效果达到90.4%，显著高于春雷霉素的防治效果84.1%。综上所述，本文首次报道了一株对植物病原细菌具有抗菌活性的产酶溶杆菌生防菌株CX03，其生防性状优良，在植物病害生物防治中具有一定的应用潜力，为国内生物防治研究提供了新的微生物资源。

Isolation,Identification and Biocontrol Effect of Lysobacter enzymogenes CX03

The biocontrol agent CX03 with strong antagonism to bacterial black rot of cabbage was isolated from the rhizosphere soil of pepper. According to biological characteristics, 16S rDNA sequence analysis, Biolog determination and physiological and biochemical analysis, the strain CX03 was identified as Lysobacter enzymogenes. The results of the enzymatic test showed that the strain CX03 produced cellulase, protease and chitinase in the metabolic process. The analysis of the antibacterial spectrum showed that the strain CX03 has a broad-spectrum antagonistic effect against five pathogenic bacteria including Xanthomonas campestris pv. campestris; Clavibacter michiganensis subsp. michiganensis, and four pathogenic fungi including Fusarium oxysporum and Phytophthora capsici. Treatment with strain CX03 significantly reduced the incidence of bacterial black rot of cabbage, and enhanced the control effect up to 90.4%, which was significantly higher than the control effect of kasugamycin. This study is the first report in China that L. enzymogenes has antibacterial activity against phytopathogenic bacteria, which provides new microbial resources for biological control research.