选用具有不同比例热带血缘种质的5个自交系和9个群体在海南进行杂交组配，挑选优良育种潜力的种质材料，研究适应西南地区的玉米种质最佳的热带血缘比例。采用NCⅡ遗传交配设计，制成45份顶交种，在宜昌市3个试验点进行田间联合试验鉴定。通过GCA与SCA分析表明，MN804、MN801、MN797、MN767为高产优良育种材料，MN797×MN767、MN804×MN771、MN801×MN770为高产优良组合；MN797、MN803、MN767、MN770抗病性好，可进一步对以上材料进行利用。热带血缘占比较低(25%)或较高(80%以上)都不利于优良种质材料的筛选，热带血缘占比在40%～66%的种质材料表现更好，更容易获得性状优良的育种材料，在改良西南地区的种质材料时可以适当对热带血缘比例进行调整。

In order to select high-quality breeding materials with potential for adaptation to the southwest region, and to investigate the optimal proportion of tropical bloodlines for maize germplasm that is suitable for the region, five inbred lines and nine populations with varying ratios of tropical genes were selected for hybridization in Hainan. Using the NCII genetic mating design, 45 top-crossing varieties were produced and evaluated in field trials at three experimental sites in Yichang City. The GCA and SCA analysis showed that MN804, MN801, MN797, and MN767 were high-yielding and excellent breeding materials. MN797×MN767, MN804×MN771 and MN801×MN770 were high-yielding and excellent combinations, and MN797, MN803, MN767, and MN770 had good disease resistance and could be further utilized. A low(25%) or high(more than 80%) proportion of tropical bloodlines was not conducive to the selection of high-quality breeding materials, while germplasm with a proportion of tropical bloodlines ranging from 40% to 66% performed better and were more likely to produce high-yielding breeding materials with desirable traits. When improving germplasm in the Southwest region, the proportion of tropical bloodlines can be adjusted appropriately.

S513.033

湖北洪山实验室重大项目课题资助项目(2022HSZD003)