河北省小麦叶锈菌不同生理小种对三唑酮的敏感性分析与田间验证OA

To clarify the sensitivity of different physiological races of Puccinia triticina(Pt)in Hebei Province to triadimefon,samples of wheat infected with Pt were collected from nine regions in Hebei Province from 2023 to 2024.Single-spore isolation was employed to isolate Pt strains,test hosts were used to identify the physiological races,and the spore germination inhibition method was adopted to determine the sensitivity of physiological races to triadimefon.The resistance differences of physiologi-cal races to triadimefon across different regions in Hebei Province were compared,their sensitivity to this fungicide was monitored,and the cross-resistance of different triazole fungicides was investigated,followed by field validation.The results showed that a total of 193 Pt strains were isolated,and 12 physiological races were identified,with THTT and PHTT being the prevalent races.The EC50 of triad-imefon against the tested strains ranged from 5.09 to 51.04 μg/mL,and the sensitivity baseline was established as 8.07 μg/mL.Sensitive strains accounted for 97.41%of the total,with only five resistant strains detected,primarily from Handan City and Shijiazhuang City,which should be designated as key areas for fungicide resistance monitoring.No significant cross-resistance was observed between triad-imefon and other fungicides sharing the same mechanism of action,including tebuconazole and hexa-conazole.Field efficacy trials were conducted to test six commonly used fungicides,demonstrating that 25%pyraclostrobin suspension concentrate exhibited the best control effect with a long duration,making it the preferred fungicide for control.In contrast,44%triadimefon suspension concentrate exhibited the poorest control efficacy and is recommended for cautious use.