玉米淀粉含量的杂种优势与基因效应分析

以10个玉米自交系及按10×10完全双列杂交设计的90个F2杂交组合在两个地点的试验资料，研究玉米淀粉含量的杂种优势和基因效应。结果表明，淀粉含量表现正向的平均杂种优势，但变异幅度较小，最大值在10%左右，并在组合间、地点间存在极显著差异；淀粉含量的遗传符合加性-显性模型，不存在上位性效应。基因显性效应的作用远大

Heterosis and Gene Effects of Grain Starch Content in Maize(Zea mays L.)

To improve starch content in maize kernel, a good knowledge of genetic system controlling its expression is essential for choice of efficient breeding and selection procedures. The objectives of this study were to investigate the heterosis and gene effects of starch content. Ten maize inbred lines with different starch percentages were crossed in a diallel mating design. Parents and their 90 F_1 single crosses were grown in a randomized complete block design experiment at two sites in 2002. Grain samples were evaluated for percent starch by near infrared reflectance spectroscopy (NIRS). Starch content showed positive and relatively low average heterosis, which was about 10%. However, significant differences in magnitude of the heterosis were observed among combinations and locations. Results of 3N genetic model analysis revealed that the inheritance of starch content was in agreement with additive-dominant model, and there was no epistasis. The dominant gene effects played predominant role in the genetic variation of starch content. Alleles controlling high starch content were dominant to those for one. Estimates of dominance variation component would be underestimated when 2N genetic model was used to analyze the 3N endosperm traits, suggesting the importance of employing appropriate genetic model for the analysis of grain quality traits. Some strategies for the genetic improvement of starch content in maize was discussed briefly in pre(sent paper. )