【作者】 张征锋；

【导师】 明道绪；

【作者基本信息】 四川农业大学 ， 作物遗传育种， 2002， 硕士

【摘要】 以9个玉米自交系和按4×5不完全双列杂交设计组配的20个杂交种为材料，对多性状综合杂种优势测定方法的应用进行了初步探索，结果表明： 1．用多性状综合杂种优势并结合“产量因子”主成分杂种优势筛选出5个强优势杂交组合：RP15×特005、ST10×1584、ST6×1584、ST10×9523-1111和ST10×特005，其产量均高于其它组合，位于前5位，比仅以产量优势为标准的选择效果好，表明多性状综合杂种优势可作为评价杂交组合表现优劣的一个可靠指标。 2．多性状综合杂种优势与遗传距离和杂交综合指数的相关性均高于产量优势与二者的相关性。表明多性状综合杂种优势可作为研究综合杂种优势与遗传差异的一个合理参数。 3．规定主要目标性状粒重的相对重要权为0.5，并按其余性状与粒重间决定系数的大小确定其相对重要权，避免了考察性状较多，难以凭经验确定其相对重要权的不便。 4．分析了影响多性状综合杂种优势的几大因素：遗传差异大小、遗传力强弱、配合力高低及亲本的遗传基础，与前人的研究结果和育种经验一致。可为实践中利用多性状综合杂种优势提供理论指导。 5．通过本研究表明，基于主成分分析原理的多性状综合杂种优势测定方法克服了传统方法的局限性，具有如下优点： ①该法是在有显著遗传差异目标性状基础上，利用遗传相关矩阵进行主成分分析来估测的，排除了环境因素的干扰。 ②由于主成分间彼此独立，克服了性状间相关的影响。 ③考虑了各性状的相对重要权。更多还原

【Abstract】 The application of synthetic heterosis of multi-character was investigated in maize.The materials consisted of 9 inbred lines and their 20 single crosses in incomplete diallel cross design.The results are as follows:1. Five crosses:RP15x005 ,8110x1584,ST6xl584,ST10x9523-llll,ST10x 005 are selected through considering of synthetic heterosis and "yield factor" principal heterosis,and yield expression of them are better than that of other crosses.The selection effect is better than that by yield heterosis.Synthetic heterosis of multi-character can be considered as a reliable parameter to assess expression of crosses.2. The multi-correlation coefficient between synthetic heterosis of multi-character and henetic distance/comprehensive index of hybrid is higher than that between yield heterosis and them. Synthetic heterosis of multi-character can be considered as a reasonable parameter to study the relationship between heterosis and genetic divergence.3. Provide the relative significant weight of grain yield 0.5. Decide the relative significant weight of other characters based upon the decisive coefficient between them and grain yield,the summation of their relative significant weight is O.S.This method avoids inconvenience when there are so many characters than it is difficult to decide the relative i significant weight of other characters based upon experience.4. Several factors affecting synthetic heterosis are analyzed,they are Genetic divergence,heritability,combining ability and genetic basement. They can be considered as theoretical direct for using synthetic heterosis in breeding practice.5. The method of measuring synthetic heterosis of multi-character based upon the principle of principal component analysis has merits as follows:Effict of environments is eliminated because of principal component analysis based on heredity correlative matrix.Correlation among characters is eliminated because of independence among principal components.The relative importance of each character is under consideration.更多还原