玉米自交系灌浆期耐热性评价

【目的】筛选出灌浆期耐热性强的玉米自交系。【方法】在花后7~17 d以自然生长为对照,分析玻璃温室高温处理下10份新疆骨干玉米自交系产量性状的变化,采用产量热稳定性分析与千粒重热感指数相结合的方法,评价供试材料的耐热性。【结果】LX9801、PH6WC、PHB1M、海014和武314在热胁迫下产量稳定性好,其中PH6WC丰产性突出。502、KW4M029、PH6WC、PHB1M和海014等5份自交系的千粒重热感指数小于1。综合产量热稳定性及千粒重热感指数,PH6WC和PHB1M的耐热性突出,海014耐热性较好。武314可作为耐热育种亲本材料。【结论】灌浆期热胁迫下千粒重的降低,是玉米自交系产量下降的主要原因,九禾6929可作为耐热育种种质资源。

Analysis and Evaluation of the Heat Resistance of Maize Inbred Lines at Grain Filling Stage

【Objective】 The purpose of this study is to screen out self-intersection lines of corn with strong heat resistance at grain filling stage. 【Methods】Compared with natural growth at 7 days after anthesis, the changes of yield characters of 10 Xinjiang backbone maize inbred lines treated with high temperature treatment in glass greenhouse were analyzed. The heat resistance of the tested materials was evaluated by combining yield thermal stability analysis with 1,000-grain weight thermal sensitivity index.【Result】 The result showed that high temperature stress reduced grain yield, 1,000-kernel weight and volume weight, and the reduction of yield mainly attributed to the decrease of 1,000-kernel weight. LX9801, PH6WC, PHB1M, Hai014 and Wu314 displayed well thermal stability under heat-stress and normal environments, among these maize inbred lines PH6WC had the higher yield. Cultivars with heat susceptibility of 1,000-kernel weight (SKGW) <1 in this study were 502, KW4M029, PH6WC, PHB1M and Hai 014. Based on the combination of both yield thermal stability and heat susceptibility of 1,000-kernel weight index, PH6WC and PHB1M were characterized with excellent high resistance to heat stress, the next was Hai 014. Wu 314 had well yield thermal stability and high 1,000-kernel weight under both normal and heat stress environments, which could be used as a heat resistance breeding parent. 【Conclusion】 The decrease of 1,000-grain weight under heat stress at grain filling stage is the main reason for the decrease of maize inbred line yield. Jiuhe 6929 has higher 1,000-kernel weight under both environments, which can be used as a heat resistance germplasm resource.