防御假单胞ZF509的分离鉴定及其对甜瓜细菌性果斑病的防治效果研究

Isolation and Identification of Pseudomonas ZF509 and Its Control Effect on Bacterial Fruit Blotch of Melon

为了筛选对瓜类果斑病(acterial fruit blotch,BFB)具有良好拮抗效果的生防细菌,本研究从黑龙江马铃薯根际土壤中分离得到一株对西瓜噬酸菌Acidovorax citrulli具有显著抑制效果的生防菌株ZF509。经形态学观察、生理生化特征、Biolog测定和多基因系统发育树分析,鉴定菌株ZF509为防御假单胞Pseudomonas protegens。经抑菌谱分析,菌株ZF509对4种病原细菌、8种病原真菌具有显著拮抗作用。经酶活检测和抑菌物质分析,ZF509具有溶磷能力,可分泌蛋白酶,合成生物膜,产生氢氰酸,具备2-羟基、2,4-DAPG、藤黄绿脓菌素以及吡咯菌素4种抑菌物质的合成编码基因。盆栽试验结果表明,接种ZF509的处理果斑病发病的病情指数显著降低,防效可达73.46%,显著优于对照药剂噻霉酮处理。综上所述,菌株ZF509对瓜类细菌性果斑病具有良好的生防潜力和应用前景。

In order to obtain the biocontrol potential strain against bacterial fruit blotch(BFB),strain ZF509 isolated from potato rhizosphere soil in Heilongjiang Province was tested against Acidovorax citrulli.The stain ZF509 had biocontrol efficiency on BFB.Morphological and biochemical characterization tests were carried out on the stain ZF509 for identification.Phylogenetic analysis based on multilocus sequence revealed that stain ZF509 clustered with Pseudomonas protegens.Agar disk diffusion test showed that strain ZF509 had inhibitory effect on 4 pathogenic bacterial and 8 pathogenic fungi.Enzyme activity detection showed that strain ZF509 could dissolve phosphorus,secrete protease,synthesize biofilm and produce hydrocyanic acid.PCR amplification of genes of four bacteriostatic substances with specific primers showed that strain ZF509 had genes of producing 2-hydroxylated phenazine, 2,4-DAPG, pyrrolnitrin and pyoluteori. Pot experiments showed that the disease index significantly reduced after inoculation with ZF509 and the control efficacy was up to 73.46%, which was superior to that of benziothiazolinone. The strain ZF509 has excellent biocontrol and practical potential against BFB.