Abstract: 【Objective】To explore the changes of nitrogen utilization and grain quality of wheat mutation population induced by N⁺ ion beam.It can provide reference for wheat quality production.【Methods】Different wheat varieties（Lianmai No.7 and Yannong No.19） were used to analysis the changes of nitrogen utilization,grain yield,protein content and processing quality by implanting different doses of nitrogen ion beam （0,2×10¹⁶,3×10¹⁶ and 4×10¹⁶ N⁺/cm²） .【Results】The main results were as follows：The nitrogen accumulation,nitrogen harvest index,nitrogen utilization,content of protein and processing quality of mutation population of Lianmai No.7 and Yannong No.19 were decreased lower than CK.As the increasing of implanting dose,the negative effects of N⁺ ion beam on grain yield and quality of mutation population increased continuously.Nitrogen accumulation and grain yield of mutation population were decreased significantly after implanting dose of more than 2×10¹⁶ N⁺/cm².Content of protein components and processing quality of two wheat varieties decreased significantly after implanting dose of more than 3×10¹⁶ N⁺/cm².The decrease amplitude of nitrogen use efficiency and grain yield of mutation population of Lianmai No.7 were lower than mutation population of Yannong No.19 under high implanting dose,Meanwhile,nitrogen accumulation and grain quality of mutation population of Lianmai No.7 were decreased significantly.【Conclusion】The above results showed that there existed negative effects of N⁺ ion beam on grain yield,nitrogen utilization and grain quality of wheat,and the higher the implantation dose,the more significant the damage to wheat.In addition,the damage of high N⁺ ion beam dose on grain yield and nitrogen use efficiency of mutation population on Yannong No.19 were higher than Lianmai No.7,while the nitrogen accumulation and grain quality of mutation population on Lianmai No.7 were decreased significantly than Yannong No.19.

Key words: N⁺ ion beam, Implantation dose, Wheat mutation population, Nitrogen utilization, Grain quality