关键词: 玉米, 自交系改良, 交替选择, 抗逆性

Abstract:

【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.

Key words: maize, alternative selection, inbred lines improvement, stress resistance