生防菌代谢物与杀菌剂复配对花生褐斑病菌的抑制活性

Inhibitory Activity of the Combination of Biocontrol Metabolites and Fungicides Against Peanut Brown Spot Pathogen

花生褐斑病是由落花生尾孢菌(Cercospora arachidicola)侵染而引起的叶部病害。为了探究生防菌解淀粉芽孢杆菌SJ1606代谢物与化学杀菌剂的复配剂对落花生尾孢菌的抑制活性,首先采用对峙培养法检测了生防菌SJ1606对花生褐斑病菌的室内拮抗效果,然后采用菌丝生长速率法测定了抗菌脂肽、6种化学杀菌剂及抗菌脂肽和化学药剂的复配剂对病菌的抑制活性。结果表明:对峙培养法显示SJ1606对花生褐斑病菌的拮抗效应明显,抑制率达71.8%;抗菌脂肽粗提物对病菌的EC50为1 149.89 mg/L;6种化学杀菌剂对病菌抑制效果以多菌灵最佳,EC50为1.53 mg/L;其次为咪鲜胺、戊唑醇、丙环唑、吡唑醚菌酯,其EC50分别为1.74、2.15、4.50和5.40 mg/L;苯醚甲环唑的抑菌活性最弱,EC50为13.14 mg/L。化学杀菌剂与抗菌脂肽的混剂在一定比例下大多表现出增效作用,其中丙环唑与抗菌脂肽混配对落花生尾孢菌的抑制活性均为增效作用,体积比为1∶9时毒性比最高达1.39;其余5种化学杀菌剂与抗菌脂肽混配既表现有增效作用也有拮抗作用,多菌灵与抗菌脂肽混配比例为2∶8时毒性比最高为1.35。综上所述,生防菌代谢物与供试化学杀菌剂对于花生褐斑病菌均表现出了较好的抑制活性,其中丙环唑与抗菌脂肽的混配对花生褐斑病菌的抑制活性较好。研究结果可为生防菌SJ1606的开发利用和杀菌剂的科学使用提供技术支撑。

Peanut brown spot is a leaf disease caused by Cercospora arachidicola(C.arachidicola).To explore the inhibitory activity of the mixture of biocontrol metabolites and chemical fungicides,the antagonistic effect of biocontrol bacterium SJ1606 on C.arachidicola was tested by confrontation culture method,and then the inhibitory activity of antimicrobial lipopeptides,six chemical fungicides and the mixture of lipopeptides and chemical fungicides were determined by mycelial growth rate method.The results showed that the antagonistic effect of SJ1606 on C.arachidicola was significant,and the inhibition rate was 71.8%.The EC50 of crude antimicrobial lipopeptide extract was 1149.89 mg/L.Carbendazim was the best among the six chemical fungicides,with EC50 of 1.53 mg/L.The EC50 of prochloraz,tebuconazole,propiconazole and pyraclostrobin were 1.74,2.15,4.50 and 5.40 mg/L respectively.The antifungal activity of difenoc onazole was the weakest,with EC50 of 13.14 mg/L.The mixture of lipopeptides and chemical fungicides showed a synergistic effect in a certain proportion.The mixture of lipopeptides and propiconazole showed a synergistic effect on the inhibitory activity of C.arachidicola,and the toxicity ratio was up to 1.39 when the volume ratio was 1∶9.The other five chemical fungicides mixed with lipopeptide had both synergistic and antagonistic effects.When the ratio of carbendazim to lipopeptide was 2∶8,the highest toxicity ratio was 1.35.In summary,the metabolites of biocontrol bacteria and the tested chemical fungicides showed good inhibitory activity against C.arachidicola,and the mixture of propiconazole and lipopeptide had better inhibitory activity against C.arachidicola.This study will provide technical support for the utilization of biocontrol bacteria SJ1606 and the scientific use of fungicides.