Influence of Different NH₄ ⁺-N/NO₃ ^--N Ratios on Wheat Seedling Antioxidase Activities under NaCl Stress

【Objective】 The purpose of this experiment is to explore the effective ways to reduce the damage of salt stress to wheat seedlings from nitrogen form supply. 【Methods】 A hydroponics experiment was carried out to investigate the influence of different NO₃ ^--N/NH₄ ⁺-N ratios application on wheat seedling antioxidase activities and membrane permeability under NaCl stress. 【Results】 The results showed that under both salt stress and control conditions that wheat seedling plant biomass was significantly increased with increase of the ration of NH₄ ⁺-N/NO₃ ^--N supply, and wheat enzyme activities of superoxide dismutase (SOD), peroxidase (POX) and ascorbate peroxidase (APX) were significantly increased as well. Leaf membrane permeability significantly increased with the increase of NaCl concentration, however, root activity, enzyme activities of SOD, POX and APX were significantly decreased with the increase of NaCl concentration (P<0.05). 【Conclusion】 The findings indicates that the higher NH₄ ⁺-N/NO₃ ^--N ratios (NH₄ ⁺-N /NO₃ ^--N, 75/25) and purely NH₄ ⁺-N could ameliorate the adverse effect resulting from stress-resistant, and attenuate the toxic effects of salt stress to a certain extent.