Effects of alternative selection of maize inbred lines on stress tolerance improvement | 交替选择对玉米自交系抗性改良的效应

Chinese. 【目的】研究交替选择对玉米自交系抗病性、耐旱性以及产量的影响。【方法】选用中国目前玉米生产上应用面积最大的杂交种郑单958的父本自交系昌7-2和母本自交系郑58,分别在河南和海南进行抗病、耐旱、丰产性交替选择。采用田间试验与盆栽试验相结合的方法,测定灰斑病病情指数、耐旱系数、丙二醛(MDA)含量和产量及其构成因素。【结果】与基础材料相比,随着交替选择代数的增加,郑58第一至第四代衍生系的灰斑病病指分别下降了16.1%、16.6%、31.5%和33.1%,昌7-2第一至第四代衍生系灰斑病病指分别下降了28.1%、29.7%、45.3%和49.5%;随选择代数增加MDA含量逐代下降,耐旱系数逐代提高;郑58和昌7-2的第四代平均产量分别比其相应基础材料提高8.3%和9.1%。【结论】经过连续四代交替选择后,郑58和昌7-2的抗病性、耐旱性以及产量都得到了明显的提高,证明交替选择对玉米自交系抗逆性改良是有效的。

English. 【Objective】 The effects of alternative selection on drought tolerance, disease resistance and yield in maize inbred lines were studied. 【Method】 Alternative selection on disease resistance, drought tolerance and high yield was carried out in a shuttle breeding program between Henan and Hainan Provinces by using the parents of the most popular elite maize hybrid Zhengdan 958, Zheng 58 and Chang 7-2. The gray leaf spot disease index, MDA content, drought tolerance coefficient and yield of maize inbred lines were determined in a field experiment and a pot experiment, respectively. 【Result】With the advance of alternative selection generations, compared with the original material, the gray leaf spot disease index of Zheng 58 in the first to fourth generations decreased by 16.1%, 16.6%, 31.5% and 33.1%, respectively, and that of Chang 7-2 in the first to fourth generations decreased by 28.1%, 29.7%, 45.3% and 49.5%, respectively, and gradually increased in drought tolerance coefficient and decreased in MDA content as advance of alternative selection generations. The average grain yields of Zheng 58 and Chang 7-2 in fourth generation increased by 8.3% and 9.1%, respectively.【Conclusion】The disease resistance, drought tolerance and yield increased in Zheng 58 and Chang 7-2 as four generations of alternative selection. The results from this study suggested that alternative selection is effective to improve maize inbred lines for stress resistance.