Effects of Plant Growth Regulators on Germination of Black Wheat Seeds under Salt-stress

  Objective  Effects of 3 plant growth regulators on the germination of black wheat seeds under salt-stress were studied to provide possible relief for the wheat planting in saline-alkali areas.

  Method  Using a paper bedding method, 1-N aphthaleneacetic acid (NAA), gibberellic acid (GA₃) or 6-benzylamino-purine (6-BA) was applied on seeds of black wheat (Zimai 1) to observe the germination under varied salt concentrations.

  Result  The best rate, potential and other indices on the seed germination were found when 150 mg·L^-1 NAA, 200 mg·L^-1 GA₃ or 5 mg·L^-1 6-BA was used without salt-stress. The presence of NaCl:Na₂SO₄=1:1 significantly inhibited the germination. Addition of the plant growth regulators in different concentrations relieved the inhibitive effect to a certain extent. Both GA₃ at 200 mg·L^-1 and 6-BA at 5 mg·L^-1 significantly alleviated the germination inhibition when medium to low salt-stress (i.e., 40-80 mmol·L^-1) was imposed on the seeds. The germination tendency and rate were significantly decreased with increasing salt-stress. When the salt concentration was raised to 120 mmol·L^-1, only the application of 6-BA 5 mg·L^-1 exhibited an effect on the germination.

  Conclusion  The treatment of GA₃ 200 mg·L^-1 or 6-BA 5 mg·L^-1 could protect the black wheat seeds from being permanently harmed by a medium-to-low salt-stress and improve the germination.