Abstract: In the experiment, different varieties of wheat seeds and wheat seedlings were treated with different concentration gradients of hydrogen peroxide in self-made equipment, under modified hydroponic conditions. The paper observed the germination rate of wheat seeds and measured the morphological indexes （plant height, fresh weight） and physiological indexes （Proline, MDA, CAT） of seedlings under the treatment of exogenous hydrogen peroxide to research the response of different wheat varieties to exogenous hydrogen peroxide treatment and analyze the mechanism of regulating wheat seed germination and seedling development. The results showed that three wheat varieties of Chinese spring, Zhoumai 36 and Fielder, all had the highest germination rate under the treatment of 0.3 μmol/L hydrogen peroxide. While the plant height and fresh weight of Chinese spring seedlings were significantly promoted by hydrogen peroxide at 0.3 μmol/L, but inhibited at 1.2 μmol/L. Hydrogen peroxide at 0.1 μmol/L showed the best promotion effect on the seedling height and fresh weight of Fielder, while the concentration of 1.2 μmol/L showed an obvious inhibition effect. At the same time, the results of physiological indexes indicated that high concentration of hydrogen peroxide could cause oxidative damage to plasma membrane and inhibit seedling development. In conclusion, the experimental results showed that, hydrogen peroxide treatment promoted wheat seed germination and seedling development at low concentration but inhibited at high concentration, and different wheat varieties had different levels of sensitivity to exogenous hydrogen peroxide.

Key words: wheat, hydrogen peroxide, seed germination, seedling development, morphological indexes, physiological indexes