【作者】 王振华；

【导师】 张改生； 刘宏伟；

【作者基本信息】 西北农林科技大学 ， 作物遗传育种， 2003， 硕士

【摘要】 为了揭示和研究杂种小麦强优势组合的内在组配规律，本研究专门对杂种小麦亲本优势群的划分，杂种小麦F₁优势分析和F₂优势利用等问题进行了比较深入系统地研究，取得如下结果： （一）用4类11个亲本及其通过完全双列杂交配制的55个组合研究了9个性状的杂种优势和配合力，以及根据形态性状划分了有利于出现强优势组合的杂种优势群，结果表明： 1．多穗×大粒型比其它几种类型具有较高的杂种优势、超标优势，强优势组合百分率、平均特殊配合力效应和较高特殊配合力的组合百分率亦高，因此，认为多穗×大粒型是强优势组合类型。 2．F₁各性状普遍具有明显的杂种优势，各性状杂种优势大小分别为单株产量＞主穗重＞株高＞百粒重＞主穗下节长＞穗粒数＞主穗长＞主穗小穗数＞单株穗数。要获得强优势组合，3个产量构成因素中至少有两个为正向的杂种优势。 3．一般配合力和特殊配合力无必然关系，杂种优势与一般配合力相关不显著，但有一定的关系。用一般配合力较好的亲本杂交，获强优势组合的可能性较大，杂种优势与特殊配合力的正相关达极显著水平。 （二）用16个小麦品种进行RAPD标记聚类，结果表明： 1．小麦中的RAPD多态性不强，利用RAPD标记的遗传距离与小穗数杂种优势有显著的相关，但是与产量性状的杂种优势相关不显著． 2．地理差异并不代表基因组水平的差异，不同地方的品种被分为一类，同一品种的不同系可以用RAPD标记区分，说明RAPD标记可以作为小麦的一种指纹图谱用来鉴定品种。 （三）利用8个品种和通过完全双列杂交配制的28个F₁组合和28个F₂群体，研究杂种小麦F₂优势利用的可能性，结果表明： 1．杂种小麦各种性状的遗传效应符合加性-显性模型，利用加性-显性模型预测杂交小麦F₁和F₂各性状是有效的， 2．小麦F₁代和F₂代各性状基因型的群体超亲优势之间均极显著正相关，说明欲利用F₂代杂种优势，F₁代必须具有高的杂种优势，F₁代优势越强，F₂代的优势亦越强。 4．F₂群体的株高遗传因材料不同而不同，因而对F₂群体株高与亲本株高的关系的预测比较困难，但一般情况下，亲本株高差值和F₂群体株高极差符合以下方程：Y=4.499+0.184X（R=0.56**） 在一般情况下，当亲本株高差值在30厘米以内时，其组合的F₂群体极差不超过10厘米。更多还原

【Abstract】 In order to discover the inner regulation of strong heterosis combination in hybrid wheat ,the systematic and deeply research in this paper is mainly about the partition of parent group , analysis of FI heterosis and use of F2, the result as follows:I. Using four group 11 parents and their 55 hybrids by completely diallel design (Griffing II mode), heterotic pattern in hybrid wheat was studied, the result .based on the analysis of heterosis, combining ability, the frequency of heterotic hybrid in different type of combinations, indicated clearly that:(l).the crosses between more spikes and large kernel had the highest heterosis over mid-parent, high-parent and the check cultivar on yield per plant among 6 groups. The percents of crosses with strong heterosis average of SCA, and percents of crosses with higher SCA(SCA>1) of this group are also the highest among the 6 groups, it is concluded that the more spikes *large kernel is the parental combination type with strong heterosis.(2).there is common over mid-parent heterosis in Fl agronomic characters among 9 characters on which data was collected. The sequence of characters over mid-parent heterosis is yield per plant>yield per main spike > plant height >100 kernel weight>knob length under main spike >kernel numbers per main spike >Iittle spike per main spike height > numbers of spikes per plant. It is also found that the crosses with strong heterosis in yield should have at least two yield components with better positive heterosis.(3). It was found that GCA had no relationships to SCA, but correlated with heterosis . The correlation coefficients is no significant. The SCA had significant and positive correlation with heterosis.II. Using RAPD marker to classify 16 wheat cultivar, indicated clearly that: (l).the polymorphism of winter wheat was very low, RAPD marked genetic distance(GD) had significant correlation with number of little spikes per main spike over mid-parent heterosis, but had no correlation with yield heterosis. It was indicated that genome difference is not the important factor of yield heterosis.(2).It was found that geography difference was not correlate with the genome difference. Different local cultivar was classified in one group and different lines of the same cultivar was classified in different group, It was indicated that RAPD can be used as a kind of finger mapping in winter wheat.III. the MINIQUE(I) procedures were used for estimating variance components and genetic effect by analyzing 8 parents completely diallel design with Additive-Dominance mode , genotype value and F2 heterosis of F2 generation were then predicted. The result as follows:(1).Significant correlation coefficients between observed and expected genotype values and heterosis for F2 generation indicated that AD model was adaptable in prediction based upon data of parents and F| hybrids.(2). Heterosis over mid-parent value based on population mean was observed in most of the agronomic traits. Heterosis over high-parent value based on population mean was found significant correlation between FI hybrids and its F2 generation. It was indicted that F2 heterosis can be used if FI heterosis was very strong.(3) It was difficult to predict height of F2 generation, but in general circumstance, the relationship between height of F2 generation and difference height of two parents was liner and the equation is Y=4.499+0.184X (R=0.56**) .更多还原