Abstract:Ethyl methane sulfonate (EMS) is a common mutagen, which is widely used in crop mutation breeding. EMS is a kind of abiotic stress as well as mutagenesis of seeds, which can significantly reduce the germination rate of wheat seeds. In this experiment, wheat ‘Yangmai 15’ was used as experimental material. Seven EMS concentration gradients (0.0%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%) were set up, and each concentration was treated for three times (10 h, 12 h, 14 h). The effects of EMS treatment on seed germination and seedling growth of wheat were studied. The main results are as follows: (1) with the increase of EMS concentration and treatment time, the germination rate of wheat seeds gradually decreased; the growth of seedlings gradually slowed down, and the root length and leaf length significantly shortened. (2) With the increase of EMS concentration and treatment time, the degradation rate of amyloplasts in wheat endosperm slowed down. (3) Under the same treatment time, the higher the concentration of EMS, the shorter the root length, and the smaller the root crosssectional area, vascular bundle area and cortex area. The above results showed that EMS treatment could reduce the germination rate of wheat seeds, slow down the degradation rate of seed storage substances, and inhibit the growth of wheat roots.