Effect of BTH on resistance induction in wheat against Blumeria graminis f.sp.tritici

In order to study the ability of benzothiadiazole induced systemic acquired resistance in wheat against Blumeria graminis f.sp.tritici,wheat seedling and adult wheat were inoculated with B.graminis f.sp.tritici after pretreated with BTH.Suppression of the powdery mildew disease was observed in wheat pretreated with BTH.For wheat seedling,the optimum concentration of BTH for resistance induction was found to be at 0.20-0.25 mmol/L,the optimum interval between BTH induction and challenge inoculation was more than 6 days.The optimum treatment for adult wheat was spraying with 0.20 mmol/L BTH twice at tillering,through which the control effect was 60.82%,16% higher than that of the untreated.The results indicated that the BTH-induced resistance against the powdery mildew disease was a response to systemic acquired resistance,and BTH could be used to control powdery mildew in field.