以不同杂优类群的4个玉米自交系为父本,5个舍热带血缘的自交系为母本,按NCⅡ遗传交配设计组配成20个杂交组合,2008-2009连续2 a采用裂区设计田间试验,对穗长、穗粗等8个性状进行杂种优势和配合力效应分析.结果表明:1)组合间除穗行数超亲优势差异不显著外,其它各个性状的中亲优势与超亲优势均存在极显著差异；2)除粒深外,双亲平均值与F1中亲优势和超亲优势的相关系数均达到极显著水平,以中亲值预测F1的杂种优势是有效的；3)控制穗部各性状基因以加性效应为主,δ2GCA是δ2GCA的1.14～26.50倍；热带选系×旅大红骨或唐四平头群是2个较好的杂优模式；4)穗行数、出子率、穗长等狭义遗传力较高的性状宜在早代选择.%Four male inbred lines from different heterosis groups were crossed with 5 inbred lines with tropic germplasm according to NC II design to compose 20 crosses. Field trials were carried out using split plot design in 2008 and 2009. Eight ear traits including ear length,ear diameter and so forth were measured to analyze heterosis and combining ability. The results are as follows:1) in terms of heterosis over mean of parents on all traits investigated and heterosis over better of parents on all traits except for row number per ear differences among crosses were significant or highly significant. 2) the mean of parents had close relations with heterosis over mean and better of parents on all traits except grain depth,hence it's reliable to forcast the F(heterosis based on the mean of parents. 3) gene additive action was more important in the variation of ear traits since δ2GCA was 1. 14 ~26. 50 times of δ2SCA ,and the patterns of tropic lines x Lüdahonggu or Tangsipingtou group were two better models. 4 ) the traits with higher heritability in narrow sense such as row number per ear,ratio of grain weight and ear length should be selected in earlier generations.
展开▼
