生防菌代谢产物与化学杀菌剂对棉花枯萎病菌的抑制活性研究

Inhibitoryactivity of metabolites of biocontrol bacteria and chemical fungicides against Fusarium oxysporum f.sp.vasinfectum

目的:为更有效防治棉花枯萎病和研制新型生物农药提供技术依据,本研究探究生防菌代谢产物与化学杀菌剂对棉花枯萎病菌(Fusarium oxysporum f. sp.vasinfectum)的抑制活性。方法:采用对峙培养法、菌丝生长速率法测定生防菌、发酵上清液、脂肽粗提物以及化学杀菌剂对棉花枯萎病菌的抑制特性。结果:对峙培养法得出生防菌SJ06对棉花枯萎病菌的抑制率为78.24%。发酵上清液的浓度从6.25μL/mL增至100.00μL/mL对病菌的抑制率从46.90%增至80.30%,其对病菌的EC50为7.37μL/mL;脂肽粗提物的质量浓度从673.96μg/mL增至8 120.00μg/mL对病菌的抑制率从19.90%增至77.30%,对病菌的EC50为2 720.20μg/mL。棉花枯萎病菌对多菌灵、戊唑醇的敏感性较高,戊唑醇和多菌灵对病菌的EC50分别为0.34、0.49μg/mL;其次分别为腈菌唑、苯醚甲环唑和丙环唑,其对病菌的EC50分别为1.07、1.34、1.54μg/mL,而丙森锌对病菌的抑制活性较差,EC50为63.25μg/mL。结论:解淀粉芽孢杆菌发酵代谢物和戊唑醇等麦角甾醇生物合成抑制剂对棉花枯萎病菌具有较好的抑制活性。

Objective:In order to provide technical basis for more effective prevention and control of cotton Fusarium wilt and the development of new biological pesticides,this study explored the inhibitory activity of metabolites of biocontrol bacteria and chemical fungicides against Fusarium oxysporum f.sp.vasinfectum.Methods:The inhibition characteristics of biocontrol bacteria,fermentation supernatant,lipopeptide crude extract and chemical fungicides on cotton Fusarium wilt were determined by confrontation culture method and mycelial growth rate method.Results:The inhibition rate of biocontrol strain SJ06 against cotton Fusarium wilt was 78.24%by confrontation culture.When the concentration of fermentation supernatant increased from 6.25μL/mL to 100.00μL/mL,the inhibition rate increased from 46.90%to 80.30%,and the EC 50 was 7.37μL/mL.The inhibition rate increased from 19.90%to 77.30%when the concentration of lipopeptide crude extract increased from 673.96μg/mL to 8120.00μg/mL,and the EC 50 of lipopeptide crude extract to pathogen was 2720.20μg/mL.Cotton Fusarium wilt was highly sensitive to carbendazim and tebuconazole.The EC 50 to the pathogen was 0.34μg/mL and 0.49μg/mL,respectively.The EC 50 of myclobutanil,difenoconazole and propiconazole against pathogens were 1.07,1.34,1.54μg/mL,respectively.The inhibitory activity of propineb against bacteria was poor,the EC 50 was 63.25μg/mL.Conclusion:Bacillus amyloliquefaciens fermentation metabolites and ergosterol biosynthesis inhibitors such as tebuconazole have good inhibitory activity against Fusarium oxysporum f.sp.vasinfectum.