玉米无叶舌种质及其杂种优势利用

Utilization of Liguleless Germplasm and Heterosis in Maize

试验以P178/lg无叶舌自交系为供体,昌7-2、郑58自交系为轮回亲本,进行多株杂交和连续多代回交,育成3个优良无叶舌自交系综58/lg、郑58/lg、昌7-2/lg。产量配合力测验结果表明,郑58/lg无叶舌自交系一般配合力高;组合郑58/lg×昌7-2、郑58×昌7-2/lg特殊配合力高。测交种比较试验结果表明,父母本均为无叶舌自交系杂交,其杂交种叶片直立、抗倒性差、杂种优势弱;非无叶舌与无叶舌自交系杂交,其杂交种株型理想,穗上叶茎叶夹角和雄穗分枝夹角小、叶片直立、抗倒伏、杂种优势强、产量高。在杂种优势模式指导下,非无叶舌×无叶舌自交系是选育耐密玉米新品种的有效途径。

The multi-plants cross and continuous several generations saturated backcross were made with a liguleless line P178/lg as the donor and Chang 7-2, Zheng 58 as recurrent parent. Three elite liguleless inbred lines including Zong 58/lg, Zheng 58/lg, and Chang 7-2/lg were selected. The results of analysis on the yield combination ability showed that the general combining ability of line Zong58/lg was higher than the others and the special combining ability of two cross combinations, Zheng 58/lg×Chang 7-2, Zheng 58×Chang 7-2/lg were high. The results of crossing tests also showed that the hybrids from both liguleless lines had more upright leaves,poorer lodging resistance and weaker heterossis, while hybrids between ligules and liguleless lines had ideal plant type with smaller stem leaf angles and tassel branches angles, upright and narrow leaves, lodging resistance, stronger heterossis and higher yield. Based on the maize heterosis patterns, the cross method that using ligules×liguleless was one of efficient ways to breeding new maize varieties with density type.