玉米是我国第一大粮食作物，玉米生产取得的巨大成就与品种改良密切相关，而种质的合理利用，尤其是杂种优势群和杂优模式的应用起到了关键作用。本文根据国内形成的玉米选系理论，结合选系实践经验，提出双向轮回选育体系，其核心在于“双向”和“轮回”，把二环系选育、动态基因池选育、双单倍体育种、回交转育、分子辅助育种以及转基因检测和功能基因的开发等玉米选育方法有机结合。构建玉米群体双向轮回选育体系，有利于促进玉米育种工作的系统化、流程化。

Maize (Zea mays L.) is the largest food crop in China. The great achievements of maize production are closely related to the improvement of its varieties, and the rational utilization of germplasm, especially the application of heterotic groups and heterotic patterns. The basic theory and certain practical methods in selection were discussed, and proposed a two-way recurrent breeding system. The core of this breeding system is “two-way” and “recurrent”. It deeply combines the breeding methods of second cycle inbred, dynamic gene pool selection, double haploid breeding, backcross breeding, molecular marker-assisted breeding, and transgenic detection and functional gene development. The establishment of bidirectional cycle breeding system for maize population will be beneficial to promote the systematization and process of maize breeding.

财政部和农业农村部：国家现代农业产业技术体系资助(CARS-02-56); 山东省现代农业产业技术体系玉米创新团队项目(SDAIT-02-19); 山东省青年自然科学基金(ZR201910210399)