Diallel mixed-model analyses to select superior maize parental lines for Azospirillum brasilense and nitrogen-use efficiency

Abstract Breeding new maize varieties that take up more N from the soil and increase N fixation is a crucial source of combined nitrogen in agricultural systems. Thus, this study aimed to select superior maize parental lines efficient in the use of nitrogen and Azospirillum brasilense. Three experiments were conducted in two agricultural seasons aiming to allocate all diallel hybrids in three different nitrogen conditions. The experiments were performed in a RCB design with two replications, and the diallel was analyzed using the mixed model approach. The general combining ability and Azospirillum use efficiency were applied to select the best parental line. The most promising hybrid combinations were “I-08 x II-06”, “I-02 x II-04”, and “I-01 x II-02”. Parents involved were selected for the development of hybrids. Parents I-01, I-02, I-08, II-01, II-02, II-04, II-05, and II-06 were selected to explore the basic population in the A. brasilense-use efficiency breeding program.

摘要：培育从土壤中吸收更多氮素并提升固氮能力的玉米新品种，是农业系统中化合氮的重要来源之一。本研究旨在筛选高效利用氮素与巴西固氮螺菌（Azospirillum brasilense）的优良玉米亲本自交系。本研究在两个农业季开展了3组试验，旨在将所有双列杂交组合设置于3种不同氮素条件下。试验采用随机完全区组设计（Randomized Complete Block，RCB），设置2次重复，并采用混合模型方法对双列杂交数据进行分析。本研究通过一般配合力（general combining ability）与巴西固氮螺菌利用效率筛选最优亲本自交系。综合表现最优的杂交组合为"I-08 × II-06"、"I-02 × II-04"以及"I-01 × II-02"。本研究选取的亲本均用于杂交种选育，其中亲本I-01、I-02、I-08、II-01、II-02、II-04、II-05与II-06被选中，用于开展巴西固氮螺菌利用效率育种项目的基础群体研究。