贝莱斯芽胞杆菌SDTB038与化学药剂协同防治草莓枯萎病的研究

草莓枯萎病是设施草莓连作种植中的重大病害，本试验通过对前期筛选到的生防菌株进行形态学观察、生理生化指标和分子生物学检测，将筛选的菌株SDTB038鉴定为贝莱斯芽胞杆菌Bacillus velezensis。采用菌丝生长速率法测定了8种化学杀菌剂对草莓枯萎病菌的毒力，其中多菌灵、苯醚甲环唑和肟菌酯室内毒力较高。菌株SDTB038与化学杀菌剂协同防治的盆栽试验表明，药后21 d，单施10⁸ cfu/mL SDTB038发酵液对草莓枯萎病的防治效果为50.66%，对该病害具有明显的防控作用。10⁸ cfu/mL SDTB038发酵液分别与29 mg/L肟菌酯和20 mg/L苯醚甲环唑混用，对草莓枯萎病的防治效果分别达62.56%和74.01%，两组混用组合的协同作用显著。试验结果表明，10⁸ cfu/mL SDTB038发酵液能够减少化学药剂的用量，提高防治效果，推广应用价值大。

Synergistic Effects of Bacillus velezensis SDTB038 and Chemical Pesticides on Strawberry Fusarium Wilt

Fusarium wilt is one of the most serious diseases of strawberry. An antagonistic strain screened in previous study was identified as Bacillus velezensis according to its morphological and chemical properties and the 16S rRNA and gyrB gene sequences. Toxicity of eight chemical fungicides against the pathogen was tested with mycelial growth rate method. The results showed that the inhibitory activities of difenoconazole and oxystrobin were higher than those of the fungicides. Pot experiment demonstrated that the control efficacy of 10⁸ cfu/mL SDTB038 fermentation broth on strawberry Fusarium wilt was 50.66% after 21 days of application. 10⁸ cfu/mL SDTB038 fermentation broth mixed with 29 mg/L oxystrobin and 20 mg/L difenoconazole had high control effect on the disease, with the efficacies of 62.56% and 74.01%, respectively. In summary, the combined use of fermentation broth and chemical fungicides could reduce the application amount of chemical fungicides, improve the control efficacy, which has the great potential to be applied for the disease control.