玉米是全球重要粮食作物之一，其安全生产对保障粮食安全至关重要。玉米南方锈病近几年发生范围从我国黄淮海地区以及蔓延到东北地区，严重影响玉米生产。目前玉米抗南方锈病种质资源匮乏，且病原菌变异速度快，容易导致抗性丧失。因此，玉米生产及育种上都需要高抗种质。为拓宽玉米抗南方锈病种质资源，本研究以感病品种铁研378亲本和高抗南方锈病京2416K和CML496为材料，构建回交群体，利用分子标记辅助选择（Molecular Marker-Assisted Selection, MAS）结合多环境抗性鉴定，定向改良铁研378亲本的抗病性。结果表明，分子标记筛选准确率91.53%，BC3F1代遗传背景回复率平均达96%，显著缩短育种周期。田间自然鉴定结果显示，改良后代病情等级集中于中抗水平，较感病亲本（7级）抗性显著提升。本研究创制了抗南方锈病新种质，为玉米抗病育种提供了技术支撑与理论依据。

Maize is one of the world"s major food crops, and its safe production is crucial for ensuring food security. Southern corn rust has expanded its range in recent years from China"s Huang-Huai-Hai region to the Northeast region, severely impacting maize production. Currently, there is a scarcity ofgermplasm resources resistant to Southern corn rust, and the rapid variation rate of the pathogen easily leads to the loss of resistance. Therefore, highly resistant germplasm is needed for both maize production and breeding. To broaden the germplasm resources for resistance to Southern corn rust, this study utilized the susceptible parent of the variety Tieyan 378 crossed with highly resistant sources Jing 2416K and CML496 to construct backcross populations. Molecular Marker-Assisted Selection (MAS) combined with multi-environment resistance evaluation was employed to directionally improve the disease resistance of the Tieyan 378 parent. The results showed that the accuracy rate of molecular marker screening was 91.53%, and the average genetic background recovery rate in the BC?F? generation reached 96%, significantly shortening the breeding cycle. Field natural infection evaluations revealed that the improved progenies predominantly exhibited moderate resistance levels, representing a significant improvement compared to the susceptible parent (rated as level 7). This study successfully developed new germplasm resistant to Southern corn rust, providing technical support and a theoretical basis for maize disease resistance breeding.

农业生物育种重大项目“养分高效高产玉米品种设计与培育”(2023ZD0406707)