生防菌对白术根腐病菌的拮抗作用及盆栽防治效果

摘要

[Objective] To control Fusarium oxysporum efficiently that is the pathogenic bacterium of the root rot of A tractylodes macrocephala,and for the development of new high efficient biological fungicide.[Method] We isolated the F.oxysporum that was the pathogenic bacterium of the root rot from the infected A.macrocephala at Zhejiang Pan'an.The inhibition effect of the four strain Bacillus subtilis,Trichoderma harzianum,Psdeuomnoda.fluoerncnet and Bacillus thuringiensis was tested by the plate confrontation method and the activity of cell wall hydrolases and indole acetic acid content in strain fermentation filtrate.After this,we tested hypha growth and morphology of pathogenic bacteria in plate confrontation method using the scanning electron microscope.In pot expriement,we added the bacteria liquid of B.subtilis and T.harzianum in concentration of 1.0×108CFU ·mL-1 to the rot of the A.macrocephala and tested its dry weight,fresh weight,plant height and the survival statistics.[Results] It showed that four kinds of strains all can control F.oxysporum efficiently that was the pathogenic bacterium of the root rot of A.macrocephala.The Comprehensive antibacterial effect of B.subtilis and T.harzianum was better than others.The inhibitory effect of these two strains against mycelium growth of the pathogenic fungi was both above 50％.The activity of cell wall hydrolases and indole acetic acid content in strain fermentation filtrate were higher than the others;the morphology changed of pathogenic bacteria like intertwine,Twisted,hypha fracture dry and even hyphae blasted surface solvation were found under canning electron microscope;Pot experiment showed that B.subtilis and T.harzianum can effectively promote the growth of A.macrocephala,reduce morbidity and improve the biomass.[Conclusion] B.subtilis and T.harzianum both showed good antibacterial control effect either indoor or pot experiement,so our research laid the theoretical foundation for the biological control ofA.macrocephala root rot and the application of microorganism resources.%[目的]探究生防菌对白术根腐病菌的拮抗作用及盆栽防治效果,为新型、高效的生物杀菌剂的研发提供理论基础.[方法]从浙江磐安根腐病发病的白术中分离出根腐病致病菌尖孢镰刀菌,采用平板对峙法检测四株益生菌枯草芽孢杆菌、哈茨木霉菌、荧光假单胞菌和苏云金芽胞杆菌对尖孢镰刀菌的抑菌作用,同时测定菌株发酵滤液中细胞壁水解酶活性及吲哚乙酸含量,之后扫描电镜观察拮抗性代表菌株对病原菌菌丝生长及形态的影响;通过盆栽试验,将枯草芽孢杆菌和哈茨木霉菌配置成1.0×108 CFU· mL-1的菌液加入到白术根部,对白术干重、鲜重、株高及存活率进行统计.[结果]经平板对峙实验,细胞壁水解酶活性及吲哚乙酸含量检测,4种菌均可对白术根腐病病原菌产生抑制作用,其中枯草芽孢杆菌和哈茨木霉菌综合抑菌效果较好,平板对峙抑菌率达50％以上,发酵滤液中蛋白酶、纤维素酶、几丁质酶活性及吲哚乙酸含量较高;扫描电镜观察发现,枯草芽孢杆菌和哈茨木霉菌均使致病菌的菌丝生长及形态产生了影响,菌丝体发生相互缠绕、扭曲变形、褶皱、折叠、断裂、干瘪,甚至菌丝表面炸开溶解等现象;盆栽实验表明,枯草芽孢杆菌和哈茨木霉菌均可有效促进白术生长,降低发病率,提高生物量.[结论]枯草芽孢杆菌和哈茨木霉菌在室内拮抗及盆栽防治均表现出较好的抑菌防治效果,这为白术根腐病的生物防治及菌种资源的应用奠定了理论基础.