甘蓝型油菜每角粒数遗传结构和机制解析

发布时间：2018-06-26 21:40

本文选题：甘蓝型油菜 + 产量　；参考：《中国农业科学院》2016年博士论文

【摘要】：每角粒数是甘蓝型油菜产量构成因子之一,是受多因素控制的一个复杂数量性状,同时也是育种重要目标之一。在甘蓝型油菜种质资源中,每角粒数变异范围较广(约每角5粒到35粒),对于每角粒数的遗传改良具有重要的利用价值。然而目前甘蓝型油菜每角粒数自然变异的机制尚未研究清楚。本研究以极具代表性的4份多粒和5份少粒甘蓝型油菜材料为基础,从面到点,由宏观到微观,逐层深入解析影响甘蓝型油菜每角粒数自然变异的原因和机制。主要研究结果和结论有以下几点:1.细胞学分析结果表明,上述材料之间每角粒数差异主要取决于胚囊的育性和结合子的发育,其次是外界环境的变化,而花粉的育性对其影响不大(可育材料);2.遗传学分析结果表明,上述材料之间每角粒数的差异主要受母体基因型和胚基因型调控,细胞质效应不显著;3.利用其中一对差异材料(中双11和No.73290)构建F2/F2:3和RIL群体进行连锁作图分析,在A06连锁群上检测到一个共同的主效QTL-qSN.A6。然而对每角粒数进行全基因组关联发现在qSN.A6区段内没有检测到关联信号,因此我们推测该位点可能为稀有等位变异;4.利用已发表的甘蓝型油菜物理图谱,整合了目前所有定位的甘蓝型油菜每角粒数QT Ls和关联信号,并且筛选出一些与每角粒数形成相关的候选基因,为后人研究甘蓝型油菜每角粒数奠定坚实的基础;5.针对主效QTL-qSN.A6成功构建近等基因系,随后利用近等基因系分离群体和子代测验将初定位的qSN.A6位点由1910kb最终缩小到88kb,其区间含有19个完整的ORF结构;6.利用遗传学和细胞学方法解析了qSN.A6位点调控每角粒数变异的机制是由母体基因型调控的胚囊败育;7.在研究过程中,我们还意外发现qSN.A6位点对粒重有相反的作用,进一步研究表明其遗传学原因是一因多效(每角粒数是因,粒重是果)而非紧密连锁,,即qSN.A6通过影响每角粒数后以生理互作(推测可能是负反馈)的方式进而影响粒重,但是其对每角粒数的影响要远大于粒重;8.通过大田试验考察,发现qSN.A6位点最终导致NIL(ZS11)的单株产量增加了17.4%。上述结果表明qSN.A6位点对油菜单株产量起着重要的作用。
[Abstract]:The number of kernels per corner is one of the yield components of Brassica napus. It is a complex quantitative trait controlled by multiple factors and one of the important targets for breeding. In the germplasm of Brassica napus, the variation range of each kernels is wide (about 5 to 35 grains per corner), which is of great value for the genetic improvement of the number of kernels. The mechanism of natural variation in the number of kernels per corner of Brassica napus has not been studied clearly. In this study, the reasons and mechanisms that affect the natural variation of grain number per corner of Brassica napus were analyzed in depth and from the macro to microcosmic, and the main results and conclusions were analyzed. The following points: 1. cytological analysis showed that the difference of each grain number between the above materials mainly depends on the fertility of the embryo sac and the development of the binding seed, followed by the change of the external environment, and the fertility of the pollen has little effect on it (fertile material). 2. the results of genetic analysis show that the difference of the number of grain per kernels between the above materials is mainly by the mother body. The cytoplasm effect was not significant in genotype and embryo genotypes; 3. using one pair of different materials (double 11 and No.73290) to construct F2/F2:3 and RIL groups for linkage mapping analysis, a common main effect QTL-qSN.A6. was detected on the A06 linkage group, but the whole genome association of each grain number was found to be not detected in the qSN.A6 section. To the associated signal, we presumed that the loci might be rare alleles; 4. using the published physical map of Brassica napus, the number of QT Ls per kernels per corner of Brassica napus and the associated signals were integrated, and some candidate genes related to the number of kernels per corner were selected to study the horns per corner of Brassica napus for posterity. The particle number laid a solid foundation; 5. the near isogenic lines were successfully constructed for the main effect QTL-qSN.A6, and then the qSN.A6 loci were eventually reduced from 1910kb to 88kb by the isolated population and progeny test of the near isogenic lines, and the interval contained 19 complete ORF structures; 6. the regulation of each corner of the qSN.A6 locus by genetic and cytological methods was used. The mechanism of grain number variation is embryo sac abortion regulated by maternal genotype. 7. during the study, we also found that the qSN.A6 site had the opposite effect on grain weight. Further studies showed that the genetic cause was a cause of multiple effects (the number of grains per kernels, grain weight is fruit) and not tight linkage, that is, the qSN.A6 is physiological by affecting the number of grains per corner. The effect of interaction (presumably negative feedback) on grain weight was further influenced by grain weight, but the effect on grain number per kernels was far greater than grain weight; 8. through field experiments, the results showed that the qSN.A6 site eventually led to the increase of single plant yield of NIL (ZS11) and the above results showed that the qSN.A6 site played an important role in the yield of single plant of rape.
【学位授予单位】：中国农业科学院
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S565.4

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