Study On The Antimicrobial Spectrum And Bioactivity Of New Fungicide Quinofumelin

Quinofumelin(ARK-3 010)is a quinoline fungicide developed by Mitsui Agrichemicals,Japan.As a brand new compound,quinofumelin has the latest mode of action and broad-spectrum bactericidal activity.Studying the antibacterial spectrum and the sensitivity of the target organism before entering the market is of great significance for the scientific development of the biocide development and application strategy.In this paper,the antibacterial activities of quinofumelin against five important plant pathogenic fungi such as Fusarium graminearum,Botrytis cinerea,Sclerotinia sclerotiorum,Corynespora cassiicala and Fusarium moniliforme.The results showed that quinofumelin had strong antibacterial activity of these five pathogens.In vivo control,quinofumelin also exhibits superior antibacterial effect,with high in vitro efficacy and excellent grooming.A baseline of sensitivity of 100 strains of Fusarium graminearum to quinofumelin was established by inhibition of mycelial growth rate assay.The results showed that the EC50 of quinofumelin was 0.007-0.043 μg/mL,the average EC50 value was 0.019±0.001 μg/mL,and the coefficient of variation was 6.14.The frequency of different sensitive strains showed a single-peak curve distribution.The protective and therapeutic effects test showed that quinofumelin had a better control effect on inoculated Fusarium graminearum on isolated leaves,and the protective effect was superior to the therapeutic effect.Quinofumelin is superior to carbendazim in the treatment of Fusarium graminearum and is approximately equal to cymene.A baseline of sensitivity of 64 strains of Botrytis cinerea to quinofumelin was established by inhibition of mycelial growth rate assay.The results showed that the EC50 value of quinofumelin on the test strain was 0.001-0.062 μg/mL,the average EC50 value was 0.0012±0.0014 μg/mL,and the coefficient of variation was 62.The results of in vitro experiments indicated that quinofumelin was resistant to carbendazim-resistant strains.The effect of carbendazim-sensitive strains was similar,and the in vitro efficacy was better than that of carbendazim,azoxystrobin and boscalid.Quinofumelin has higher in vitro efficacy and permeability in controlling strawberry gray mold,and its protective effect is superior to therapeutic effect.The baseline sensitivity of 65 strains of Sclerotinia sclerotiorum to quinofumelin was established by mycelial growth rate assay.The results showed that the EC50 value of quinofumelin was 0.001-0.006μg/mL,the average EC50 value was 0.002±0.017 μg/mL,the coefficient of variation was 8.5,and the sensitivity of different strains showed a single-peak curve distribution;The in vivo experiments of the leaves showed that the effects of various treatments of quinofumelin on the control of Sclerotinia sclerotiorum were better than that of carbendazim and sclerotia,and the protective effect was superior to the therapeutic effect.The sensitivity baseline of 83 Corynespora cassiicala bacterium to quinofumelin was established by mycelial growth rate assay.The results showed that the EC50 value of quinofumelin was 0.002-0.158μg/mL,the average EC50 value was 0.047±0.011 μg/mL,and the coefficient of variation was 79.The sensitivity of different strains showed a single-peak curve distribution.The sensitivity baseline of 39 Fusarium moniliform pathogens to quinofumelin was established by mycelial growth rate assay.The results showed that the EC50 value of quinofumelin was 0.008-0.025 μg/mL,the average EC50 value was 0.013±0.001μg/mL,and the coefficient of variation was 3.12.The sensitivity of different strains showed a single-peak curve distribution.In summary,the new fungicide of quinofumelin has good antibacterial activity against Fusarium graminearum,Botrytis cinerea,Sclerotinia sclerotiorum,Corynespora cassiicala,Fusarium moniliforme,in vitro.The diseases caused by the above pathogenic fungi have a good prevention and treatment effect,and it is worthwhile to further carry out field trials to control wheat scab,strawberry gray mold,rapeseed sclerotinia,cucumber target spot disease and rice seedling disease.