| Addressing the issue of millet genetic diversity deficiency and drought resistance breeding bottlenecks in the arid and semi-arid regions of China (accounting for 52.5% of the country"s land area, with an average annual precipitation of < 400 mm and evaporation 3-5 times that of precipitation). Four main cultivars, including Yugui 18, were used as materials. The emergence rate of the M? generation, agronomic traits (such as plant height, tillering, and growth period), and nutritional quality variations were systematically analyzed through gradient treatment with 0 to 1% EMS concentration. The results indicated that 1% EMS was the optimal mutation concentration, with the number of M? generation mutants in each variety ranging from 127 to 220 and an average mutation rate of 18.5%. Significant variations in drought-related traits were observed, including plant height variation rates of 15.52% to 29.74% (with dwarf plants accounting for 65%), tillering variation rates of 7.66% to 23.28%, and early-maturing plant variation rates of 3.83% to 18.34%. Among quality traits, the crude fat content of Yugui 18 increased by 47.57%, while the crude protein of Jingu 5 increased by 1.39%. The mutant library constructed in this study provides crucial materials for drought resistance breeding, gene mining, and quality improvement of millets in arid regions. Furthermore, the 1% EMS concentration can serve as a key technical parameter for efficient mutation in millets. |