【摘要】 以44个杂种小麦亲本（22个恢复系,22个保持系）,两个品种,25个杂交组合（F₁）为供试材料,采用多元分析方法研究亲本材料之间的遗传距离及其与杂种优势的关系。结果表明:遗传距离与杂种优势呈曲线关系:Y=-13.120+3.955x-0.134x₂在一定范围内（D²≤14.7135）,杂种优势随遗传距离增大而增大,直线相关系数 r=0.729超过这个范围,杂种优势随遗传距离的增大反而降低,直线相关系数 r=-0.748,仅有少数几个例外。认为可用遗传距离作为杂种优势预测的一个指标.聚类分析将46个材料聚入13个类群。同类材料间杂种优势相对低于类间材料组合的优势。认为应在不同类群间选择亲本。上位性效应,减值显性基因的存在可能是曲线形成的原因,亦可能与材料适应性有关。研究时对供试材料要有所选择。更多还原

【Abstract】 The association of genetic distance of quantitative characters of parents measured by using a method of multivariate analysis and heterosis was investigated in hybrid winter wheat with Triticum timopheevi Cytoplasm.The materials consisted of twenty two R lines,twenty-two B lines,two varieties and twentyfive F1 crosses.The- results indicated that the relationship between genetic distance of quantitative characters of parents and heterosis was curvilineal Y=-13.120+3.955X-0.134X~2 and,within a restricted range,greater genetic diversity of parents was associated with greater heterosis(Linear correlation coefficient r=0.729),only with a few exceptions.The genetic distance could be used as a criterion to predict the hybrid vigor. Forty-six genotypes were grouped into thirteen genetic clusters.The crosses whose parents were selected from different genetic clusters could produce larger heterosis compared with those whose parents selected from within genetic clusters. Selection of parents from separated genetic clusters was suggensted.Some problem associated with the use of genetic distance in plant breeding were discussed briefly.更多还原