通过评价系群本身、系群间双列杂交组合、系群S_1组和系群杂交合S_1,来确定由不同轮回选择方法选择不同性状而衍生出的9个衣阿华坚秆玉米综合种的有关性能。测定了9个系群之间由选择造成的差异以及对产量、籽粒含水率、根(茎)倒伏和落穗的直接与间接效应。抗欧洲玉米螟的选择对产量的下降无明显影响,但抗玉米幼芽根叶甲的选择与产量呈明显负相关。系群间的产量差异和表现在各组合上的不同杂种优势表明该综合种系群之间由选择造成的遗传多样性。 The results showed that 9 families of Iowa stalk corn derived from different traits of selection by different methods of cycle selection were identified by evaluating lineage itself, double line cross between lines, line S_1 and line S_1 About performance The differences between the 9 lineages as a result of selection and the direct and indirect effects on yield, grain moisture content, root (stem) lodging and scion were measured. The choice of resistance to the European corn borer had no significant effect on the decline of yield, but the selection of resistant roots and leaves of maize seedlings had a negative correlation with the yield. The differences in yield between lines and the different heterosis manifested in each combination indicate the genetic diversity caused by the selection among the integrated lines.