玉米新品种‘裕丰303’的商业育种问题讨论

在大田生产中,‘先玉335’等美系新品种在耐密植、抗倒伏、抗南方锈病、抗大斑病、抗高温热害等方面的能力都较弱。为了通过育种手段解决以上问题,本研究以玉米新品种‘裕丰303’为试验材料,通过对其在国家（黄淮海夏播、东华北中晚熟、西北春播）以及各省区域试验和生产试验中的产量、抗旱性、耐高温热害、耐密性、籽粒品质等品种特性进行分析。结果表明‘裕丰303’不仅具备美系新品种的优良特征特性,还具有耐旱、耐高温热害、抗倒伏、抗南方锈病等性状优势,实现并大幅度超越笔者原定的育种目标。以此为基础,讨论了今后种质扩增、改良、创新的技术路线和避免遗传脆弱性风险出现等相关商业育种问题。强调在育种实践中应高度重视耐高温热害性状和耐旱性状的选育,特别要注重通过不断提升基因型与环境互作的正向超正常表达选育具有广泛适应性的新品种。

Maize New Variety ‘Yufeng 303’: Commercial Breeding

In field production, new maize varieties with U.S. germplasm such as ‘Xianyu 335’ are weak in resistance to dense planting, lodging, Southern Corn Rust, leaf blight, and high temperature and heat. To solve these problems by means of plant breeding, we use maize new variety ‘Yufeng 303’ as the test material to study its performances, including yield performance, drought tolerance, high temperature and heat tolerance, dense planting resistance, and grain quality at production trials, at national trials (Huang-huai-hai Summer Maize Area, Eastern of North China Middle and Late Maturity Spring Maize Area, and Northwest Spring Maize Area) and provincial trials. The results show that ‘Yufeng 303’ not only possesses the desirable traits of new maize varieties with U. S. germplasm, but also has traits of high tolerances to drought, high temperature and heat, lodging, and Southern Corn Rust, achieving and substantially surpassing our original breeding goal. Based on these results, several issues for future breeding, including the general technical route of germplasm expansion, improvement and innovation, the avoidance of genetic vulnerability risk and others related to commercial breeding, are discussed. The study emphasizes the importance of breeding the traits of high temperature tolerance and drought tolerance, especially the importance of breeding new varieties with wide stress adaptability by constantly uplifting the positive super normal expression of genotype environment interaction.