采用平板对峙法,从分离自土壤的436株细菌菌株中筛选对草莓根腐病菌——尖孢镰刀菌(Fusarium oxysporum)具有拮抗作用的细菌,得到了3株稳定性好,具有较高拮抗活性的菌株w-25、w-79和w-181。拮抗菌w-25对尖孢镰刀菌的抑菌带达到11.0mm,w-79和w-181的抑菌带分别达到5.4和6.4mm。此外,3株拮抗菌对草莓灰霉病菌(Botrytis cinerea)、草莓红中柱致病菌(Fragria ananassa)和草莓胶孢炭疽病菌(Colletotrichum gloeosporioides)等具有很强的拮抗作用。经过对3株菌株形态观察、理化分析和分子鉴定,认为w-25可能为荧光假单孢菌(Pseudomonas fluorescens),w-181和w-79可能为枯草芽孢杆菌(Bacillus subtilis)。研究表明3株拮抗菌对致病菌生长有较好的抑制作用,显微观察发现拮抗菌代谢产物会破坏致病菌菌丝形态,电镜观察发现致病菌细胞器溶解,细胞内液泡变大。 Three strains of bacteria with antagonistic activity to strawberry root rot fungus Fusarium oxysporum were screened from 436 isolates of bacteria isolated from soil by using the plate confrontation method. Three strains with good stability and high antagonistic activity Strains w-25, w-79 and w-181. The antibacterial bands of antagonistic fungus w-25 to Fusarium oxysporum reached 11.0mm, and the antibacterial bands of w-79 and w-181 reached 5.4 and 6.4mm respectively. In addition, the three antagonistic bacteria have a strong antagonistic effect on Botrytis cinerea, Fragria ananassa, and Colletotrichum gloeosporioides. Through the morphological observation, physicochemical analysis and molecular identification of the three strains, we think that w-25 may be Pseudomonas fluorescens, w-181 and w-79 may be Bacillus subtilis. The results showed that the three antagonistic bacteria had a good inhibitory effect on the growth of pathogenic bacteria. Microscopically, it was found that the metabolites of antagonistic bacteria could destroy the mycelial morphology of pathogenic bacteria. Electron microscopy showed that the organelles of pathogenic bacteria were dissolved and the vacuoles of intracellular vacuole became larger.