Response and Tolerance Threshold of Bainong Aikang-58 Wheat Seedlings toward Na₂SO₄ Stress

  Objective  Bainong Aikang-58 is one of the major wheat cultivars in China. To investigate the response mechanism of Bainon Aikang-58 seedling to Na₂SO₄ stress was discussed and to define its tolerance threshold to Na₂SO₄ stress was determined so as to provide basic data support for further research and scientific basis and and theoretical guidance for agricultural production practice.

  Method  Effects of Na₂SO₄ stress at 0, 20, 40, 60, 80, and 100 mmol·L⁻¹ on the growth and physiology of the wheat seedlings were studied in a hydroponic experimentation.

  Result   As the Na₂SO₄ concentration in the medium increased, the plant height, fresh weight, and biomass of the seedlings decreased. The activity of each antioxidant enzyme in wheat seedlings would continuously increase with the increase of Na₂SO₄ concentration, and would decrease after exceeding a certain threshold. The membrane permeability and content of MDA in the synplasmic membrane increase with increasing of Na₂SO₄ concentration to maximize 3.2 and 4.94 times of the control. The chlorophyll content in the leaves were decreased with the increase of Na₂SO₄ concentration. The soluble sugar content in wheat increased first and then decreased with the increase of Na₂SO₄ concentration. The soluble sugar concentration was the highest at 80 mmol·L⁻¹ Whereas, the proline content kept increasing to reach a maximum that was 8.51 times of control.

  Conclusion  The tolerance threshold of Bainong Aikang-58 wheat seedling toward Na₂SO₄ stress was determined to be 80−100 mmol·L⁻¹.