【作者】 段有德；

【导师】 李加纳；

【作者基本信息】 西南农业大学 ， 作物遗传育种， 2004， 硕士

【摘要】 在相同遗传背景下，黄籽油菜具有高含油量和高蛋白质含量、低粗纤维含量、低酚类化合物含量，不及黑籽产生的大量具有苦涩味的单宁、鞣酸等多酚化合物，油的品质好，蛋白质可消化率较高和检察种子成熟较易等优点，鉴于黄籽油菜的诸多优良特性，选育黄籽类型品种则被国内外油菜育种工作者作为改造甘蓝型油菜品质的一条非常重要途径。但甘蓝型黄籽油菜种皮色泽与白菜型和芥菜型油菜种皮色泽的遗传行为明显不同。在研究甘蓝型黄籽油菜的遗传机制时，前人主要从两个方面入手：一方面把种皮色泽的遗传单独作为质量性状来分析；另一方面由于种皮颜色深浅不一，又将其视为数量性状进行分析。实际上，由于甘蓝型黄籽油莱来源复杂，种皮色泽呈现出了独特特点：不仅呈现出质量性状遗传的特征，还呈现出数量性状遗传的特征，属于典型的质量-数量性状，应用主+多基因遗传模式对其进行分析。 本文通过已选育稳定的黄籽自交系GH06作为同一母本与稳定遗传的两黑籽自交系94005和A800杂交，分别利用它们组合的6个世代（P₁、P₂、F₁、B₁、B₂和F₂）通过植物数量性状遗传体系主基因+多基因的联合世代分离分析法对种皮色泽和皮壳率的遗传作了系统分析，同时在各分离世代研究了所考察性状间的相关性。论文主要结果如下： 1．利用实物解剖显微镜测定种皮的曝光时间，通过计算它们的粒色指数（T₂/T₁）能区分不同色泽的种子。粒色指数越低，其种皮色泽越黄。从论文的结果和分析可看出，此种方法在实际运用中是可行的，它可以快速、准确反映种子种皮色泽之间的差异，并可以克服以往在判断种皮色泽时人为因素等的影响。 2．对两组合种皮色泽进行主基因+多基因混合遗传分析表明，甘蓝型黄籽油菜种皮色泽属于质量-数量性状，其遗传为1对主基因+多基因的混合遗传，多基因效应对种皮色泽具有很强的修饰作用，同时环境对种皮色泽的影响较大。该黄籽和两个黑籽亲本间的主基因作用方式可能属于同一位点存在不同复等位基因的遗传模式。假设Sc¹、Sc²和Sc³为主基因的三个不同复等位基因，其效应值为Sc¹＞Sc²>Sc³。黄籽GH06主基因的复等位基因型为Sc²Sc²，黑籽94005主基因的复等位基因型为Sc¹Sc¹，黑籽A800主基因的复等位基因型为Sc³Sc³。由于Sc¹复等位基因的效应大于Sc²，复等位基因型Sc¹Sc²表现为黑籽；Sc²复等位基因的效应大于Sc³，复等位基因型Sc²Sc³则表现为黄籽。在组合GH06×94005的1对负向完全显性主基因+加性-显性多基因混合遗传模型中，多基因的加性和显性效应对种皮色泽的影响大。该组合主基因遗传率以B₁最高，B₂和F₂均较低；多基因遗传率B₂和F₂较高，而B₁最小。对于B₁、B₂和F₂，其主基因+多基因的遗传率分别为76.83％、61.44％和68.31％，环境方差占表型方差的23.17％～38.56％。在组合GH06×A800的1对加性-显性主基因+加性-显性多基因模型中，主基因显性效应为正向显性，其显性效应绝对值略大于加性效应。在多基因效应中，其加性效应明显，而显性效应较小。主基因遗传率以B₂最高，其次是F₂和B₁；多基因遗传率B₁和F₂较高，而西南农业大学硕士学位论文BZ较小。对于B、、BZ和FZ，其主基因十多基因的遗传率分别为55.34%、85.92%和71.72%，环境方差占表型方差的14.08%⁴4.66%。 3.对两组合种子皮壳率进行主基因+多基因混合遗传分析表明，随组合不同，其皮壳率的遗传表现为多基因遗传模式和l对主基因+多基因遗传模式，环境对皮壳率有一定的影响.黄籽复等位主基因scZ可能具有一因多效的作用，它不仅作用于种皮色泽的表达，同时还影响皮壳率的遗传.在组合GH06x94005中，由于sc，复等位基因的效应大于scZ，抑制了s矛主基因的表达，而sc，主基因对皮壳率不具有主效作用，所以皮壳率在该组合中则表现出数里性状的多基因遗传。多基因存在加性、显性效应和加性x加性，加性x显性，显性x显性多种互作效应，其显性效应和互作效应均较明显。多基因遗传率在B，、BZ和凡代相差不大，分别为79.56%、”.71%、78.68%。环境方差占表型方差的20.44%²2.2少场。在组合GH06xA800的1对加性主基因+加性一显性多基因混合遗传模型中，主基因以加性为主;多基因效应加性效应明显，显性效应不明显。说明控制该组合种子皮壳率这个性状的遗传主要是加性效应的作用。主基因遗传率以凡最高，其次为BZ和B:;多基因遗传率以氏和B，较高，凡较低。对于Bl、几和FZ，其主基因+多基因的遗传率分别为79.16%、92.53%和89.18%，而环境方差占表型方差的 一.岁7.47%²0.84%。 4.各性状间在回交世代和凡代的相关分析表明，各性状间的相关性在各分离世代中表现基本一致，除有个别世代和性状结果有细微善别外·简单相关分析表明，种皮色泽与皮壳率间呈极显著正相羌，与种子含油量、饼粕蛋白质含量和皮壳含油量间均存显著或极显著负相关.皮壳率与种子含油量和饼粕蛋自质含里均呈极显著负相关，与皮壳含油量在组合的部分世代皇极显著负相关.饼粕蛋白质含量与种子含油量、皮壳含油量间及种子含油量与皮壳含油量间几乎?更多还原

【Abstract】 Yellow-seeded rape has higher oil and protein content, lower crude fiber and polyphenol content, good oil quality and higher protein digestion and easier way to examine seed ripeness compared with dark-seeded rape under the same genetic background. For the mang merits, yellow-seeded rape breeding is considered as a very important approach to improve Brassica napus quality by many oil breeders all over the world. But the inheritance of seedcoat color in Brassica napus is apparently different from ones in Brassica campestris and in Brassica juncea. Some researchers had made many studies about the inheritance of seedcoat color in Brassica napus, but they considered seedcoat color in Brassica napus mainly as either qualitative or quantitative traits when they studied. In fact, as yellow-seeded Brassica napus L. may be obtained from different breeding approaches, its seedcoat color has showed distinctive characteristics, which has not only showed the inheritance characteristics of qualitative traits but also the ones of quantitative traits, and belongs to the qualitative-quantitative traits and should be analysed by major gene-polygene mixed inheritance model.This paper made a systemic study about the inheritance of seedcoat color and seed husk content in yellow-seeded rape {Brassica napus L.) by applying the major gene plus poly-gene model of genetic system of quantitative traits through a joint segregation analysis of P1,F1,P2,B1,B2 and F2 generations of the crosses of both GH06 (yellow-seeded self-crossing line) x 94005 (black-seeded self-crossing line) and GH06 x A800 (black-seeded self-crossing line). At the same time, the correlations among some traits were also studied in the backcross generations and F2 generations of both the crosses in this paper. The conclusions in this paper were mainly as follows:1 .The seed-colour coefficient (T2/T1) that obtained from the exposure time of seedcoat measured by dissection microscope could distinguish from seeds with different seedcoat color. The lower the seed-colour coefficient was, the yellower the seedcoat colour. It was an effective way to show the difference of the seedcoat color quickly and truly through calculating the seed-colour coefficient of seeds with different colour from the results and analyses in this paper, and also overcome the influence of subjective factors when estimating the seedcoat color in the past.2.The results indicated that the seedcoat colour in yellow-seeded Brassica napus L. belonged to qualitative-quantitative trait whose inheritance was the mixed inheritance of one major gene plus poly-gene, that poly-gene effects and environments had a strong modified function to the seedcoat color by applying the major gene plus poly-gene model of genetic system of quantitative traits through a joint segregation analysis of P1, F1,P2,B1,B2 and F2 generations of both the crosses. The interaction mode of major genes between the yellow-seeded line (GH06) and two black-seeded lines (94005 and A800) may belong to the inheritance mode of existing the different poly allele genes in the same locus. If the three different poly allele genes of the major gene wore Sc1, Sc2 and Sc3 respectively and the relation on their effect values was Sc1> Sc2> Sc3, the poly allele genotype of the major gene in yellow-seeded GH06 was Sc2Sc2 and that in black-seeded 94005 was Sc1Sc1 and that in black-seeded A800 was Sc3Sc3. As the effect of Sc1 was dominant to Sc2, the poly allele genotype Sc’Sc2 behaved with black seed . As the effect of Sc2 was dominant to Sc3, the poly allele genotype Sc2Sc3 behaved with yellow seed. In the mixed inheritance model of one major gene with negative completely dominance plus polygenes with additive and dominance in GH06x94005, the additive and dominance effects of the polygenes had a great influence on seedcoat colour. In the cross of GH06x94005, the major gene heritability of B1 was higher than the one of B2 and F2, and however the poly-gene heritability of B2 and F2 was higher than the one of B,. The heritability of seedcoat color更多还原