玉米新品种‘中科玉505’的选育及相关商业育种问题探讨

The Breeding of Corn Hybrid‘Zhongkeyu 505’and Its Implication for Commercial Breeding

通过对玉米新品种‘中科玉505’特征特性的分析,为该品种在生产上的大面积推广提供数据和理论依据。以此为基础,结合选育过程的体会,以期为玉米商业育种体系构建提供一定的思路和方法。以自选系CT1668为母本、CT3354为父本组配选育而成的玉米新品种‘中科玉505’,基于国家和省级区域试验试多年多点数据,对其产量表现及其农艺性状、抗旱性、耐高温性、耐密性、籽粒品质和青贮的饲用品质进行分析。结果表明:该品种产量比对照种‘先玉335’平均提高3.4%,‘郑单958’平均提高8%以上,在穗长、穗粗、行粒数、单穗粒重和出籽率等穗部性状优于对照;抗旱性达到“极强”标准,耐高温性达到“中等”水平,同对照‘郑单958’相当;籽粒容重746 g/L,粗蛋白含量10.1%,粗脂肪含量3.36%,粗淀粉含量74.26%,赖氨酸含量0.3%;秸秆的相对饲用品质优于‘先玉335’和‘郑单958’。该品种为新型优良玉米杂交种,具备很强的推广前景和价值。在玉米商业育种过程中要特别关注新品种市场安全性评价、制种产量、茎腐病、穗腐病、大小斑病、南方锈病、合理密植与控制倒伏等因素,建立有限回交与大群体逆境筛选相结合的育种方法。

The performance and characteristics of the new corn hybrid‘Zhongkeyu 505’are reported here to provide theoretical and practical information needed for large-scale commercialization of this hybrid.‘Zhongkeyu 505’was developed by crossing CT1668 as female parent and CT3354 as male parent.The yield performance,agronomic traits,drought resistance,high temperature tolerance,density tolerance,grain quality,and silage forage quality were analyzed based on the multi-year and multi-location data from national and provincial trials.The results showed that the yield of this hybrid increased by 3.4%and 8%respectively on average compared with that of the two check hybrid‘Xianyu 335’and‘Zhengdan 958’.The ear characters such as ear length,ear diameter,kernel number per row,grain weight per ear and grain yield were better than those of the check hybrid.The drought tolerance reached the extremely strong standard,and the high-temperature tolerance reached the medium level equivalent to that of the check‘Zhengdan 958’.The grain test weight was 746 g/L,the crude protein,crude fatty acid,crude starch,and lysine content reached 10.1%,3.36%,74.26%,and 0.3%respectively.The relative stalk feed quality was better than that of‘Xianyu 335’and‘Zhengdan 958’.This hybrid is an excellent one of significant commercial value.In the process of commercial breeding of maize,special attention should be paid to the factors of the market safety evaluation of new varieties,seed production yield,stem rot,ear rot,Southern and Northern leaf blight,Southern rust,suitable planting density and lodging control etc.,thus establishing a breeding method combining limited backcrossing with large population adversity screening.