Effect of potassium and nitrogen on the resistant of wheat against FHB

In order to study the effects of potasium and nitrogen on the antioxidant enzyme activity and changes of osmolytes in wheat under fusarium head blight infection, an experiment was carried out as a factorial based on completely randomized design with three replications. Treatments included two levels of FHB infection (Control and infected), three levels of potassium (80, 100 and 120 kgha-1) and three forms of nitrogen (ammonium sulfate, calssium nitrate, combination of two nitrogen form consisted of 75% calssium nitrate and 25% ammonium sulfate).Results showed that infection, potasium and nitrate led to increase of superoxide dismutase, catalase and polyphenol oxidase activity, prolin and soluble sugers content. Also infection and potasium decreased total protein and lysin content. Amount of methionin declined under FHB infection Ammonium sulfate led to decrease of these enzymes, proline and soluble sugars. It seems that Fusarium head blight of wheat leads to increase antioxidant enzymes activity and the use of potassium and nitrate caused a greater impact on reduction of the harmful effects of this disease than ammonium, because ammonium lowers the amount of osmolites and activity of antioxidant enzymes.It seems that Fusarium head blight of wheat leads to increase antioxidant enzymes activity and the use of potassium and nitrate caused a greater impact on reduction of the harmful effects of this disease than ammonium, because ammonium lowers the amount of osmolites and activity of antioxidant enzymes.