己唑醇及其复配剂对河南省禾谷镰孢菌的抑制活性及对小麦赤霉病的室内防效OA北大核心CSTPCD

Fusarium graminearum is the dominant pathogen causing wheat Fusarium head blight(FHB)in Henan Province.To elucidate the inhibitory activity of hexaconazole against F.graminearum in Henan Province,this study determined the toxicity of hexaconazole on F.graminearum at different developmental stages and the inhibitory activity of hexaconazole against 205 F.graminearum strains collected from six regions in Henan Province was determined using the mycelial growth rate method.Finally,the coleoptiles of wheat inoculation were used to determine the indoor control efficacy of hexaconazole against FHB.The results indicated significant variations in inhibitory activity of hexaconazole against F.graminearum at different developmental stages,with EC50/(μg/mL)values ranking as follows:spore germination(22.5750)>sporulation quantity(2.1686)>sprout tube elongation(0.8922)>smycelium growth(0.3862).The EC50 value of hexaconazole against 205 strains of F.graminearum ranged from 0.0345 to 0.9439 μg/mL,with an average EC50 value of(0.3578±0.1928)μg/mL.The frequency distribution of sensitivity exhibited a continuous single-peak curve,suggesting the absence of subpopulations with reduced sensitivity to hexaconazole.The results of the combination toxicity between hexaconazole and carbendazim,fluoxazonil,phenamacril,prochloraz,and pydiflumetofen revealed various additive or synergistic effects.The synergy ratio(SR)ranged from 0.5042 to 3.7293,with the maximum value observed at a ratio ofm(hexaconazole):m(pydiflumetofen)=1:5(SR=3.7293),yielding an actual EC50 value of 0.0133 μg/mL.The results of indoor control efficacy showed that the combined fungicides exhibited significantly higher control efficacy compared to single fungicides,namely carbendazim,hexaconazole,and pydiflumetofen.The control efficacy of m(hexaconazole):m(pydiflumetofen)=1:5 on coleoptiles of wheat was 93.93%at a concentration of 9 μg/mL.In practical applications,hexaconazole should be combined or rotated with fluoxazonil or pydiflumetofen to prevent or delay the development of field resistance.This study provides crucial theoretical and data support for the rational use of hexaconazole and comprehensive control of FHB.