试验以自交系B73、Mo17、444、丹340为测验种，采用NCⅡ设计对品综1号群体、中综3号群体、陕综5号群体选育的18份自交系进行配合力及杂种优势分析。结果表明：选自同一群体和不同群体间的自交系配合力有较大差异，陕综5号群体选系有3个、品综1号群体选系有1个一般配合力较高。陕综5号选系与丹340、中综3号选系与Mo17和B73、品综1号选系与444和丹340特殊配合力较高，杂种优势较强。

Combining ability and heterosis of 18 inbred lines were analyzed using 4 inbred lines (444, B73, Mo17 and Dan340) as common testers in a NC-Ⅱ mating design. The inbred lines tested were selected from Pinzong1 population, Zhongzong 3 population and Shanzong 5 population. The results showed that highly significant differences existed in combining ability among inbred lines which were chosen from the same population and from different populations. Three inbred lines obtained from Shanzong 5 population and one line from Pinzong 3 population had high GCA (general combining ability). There was high SCA and heterosis in inbred lines obtained from Shanzong 5 crossed with Dan 340 and in lines from Zhongzong 3 crossed with Mo17and B73 and in lines from Pinzong 1 crossed with 444 and Dan 340.