甘蓝型油菜千粒重位点qSW.C9的候选基因分析

发布时间：2018-05-08 21:11

本文选题：甘蓝型油菜 + 千粒重　；参考：《华中农业大学》2017年硕士论文

【摘要】：甘蓝型油菜(Brassica napus L.)是世界上重要的油料作物之一,提高产量是油菜育种研究的重要目标。油菜的产量由种植密度和单株产量共同决定,其中种植密度与油菜的株型紧密相关;而单株产量取决于单株角果数、每角果粒数和千粒重三个因子的协调作用。到目前为止,已有大量单株产量构成因子相关QTL被报道,但只有2个QTL通过图位克隆的方法得到基因:即控制千粒重的QTL(BnaA09.ARF18)和控制每角果粒数QTL(BnaC9.SMG7b)。李世鹏[1]在克隆甘蓝型油菜每角果粒数主效QTL qSS.C9(BnaC9.SMG7b)的过程中发现,NIL(Y106)每角果粒数显著性增加,但同时千粒重显著下降。这种随着每角粒数增加而千粒重下降的变化可能是BnaC9.SMG7b的一因多效,也可能由其他基因所致。进一步的序列分析显示,在qSS.C9定位区间的BnaC9.RINGb基因可能直接参与调控种子的发育。本研究在此基础上,通过比较基因组学和分子生物学的方法,对qSS.C9定位区间内的候选基因进行了研究分析。主要结果如下:1.BnaC9.SMG7b基因互补验证:转基因互补实验表明,BnaC9.SMG7b基因对千粒重没有显著影响。这表明可能存在其它基因对NIL(Y106)的千粒重起到调控作用。2.候选基因分析:对qSS.C9定位区间内的候选基因进行比较测序发现,BnaC9.RINGb在双亲之间存在明显差异;初步的转基因互补试验结果显示,BnaC9.RINGb基因负调控千粒重,使受体材料HZ396的千粒重显著下降,极可能是目标基因。3.BnaC9.RINGb同源拷贝分析:序列比对结果发现BnaC9.RINGb基因在拟南芥有1个同源基因,甘蓝型油菜中有8个,甘蓝中有3个,白菜中有3个。4.表达模式分析:GUS染色分析,该基因在拟南芥的子叶、叶片、角果皮、雌蕊和雄蕊中都有表达,亚细胞定位表明该基因表达蛋白定位于细胞核。5.拟南芥同源基因功能研究:部分ring突变体的角果长、角果宽和每角果粒数显著高于野生型:突变体的千粒重比野生型材料有一定的增加,但并未达到显著水平。
[Abstract]:Brassica napus L. It is one of the most important oil crops in the world, and increasing yield is an important goal of rapeseed breeding. The yield of rape was determined by planting density and yield per plant, in which planting density was closely related to plant type, and yield per plant depended on the coordination of three factors: the number of pods per plant, the number of kernels per pod and the weight of 1000 seeds. Up to now, a large number of QTL related to yield components per plant have been reported, but only two QTL genes have been obtained by map cloning: QTLL BnaA09.ARF18, which controls 1000-grain weight, and QTLL BnaC9.SMG7b, which controls the number of kernels per pod. Li Shipeng [1] found that the number of kernels per pod increased significantly, but the 1000-grain weight decreased significantly in the process of cloning the main effect QTL qSS.C9C9BnaC9.SMG7b per pod of Brassica napus. The decrease in 1000-grain weight as the number of kernels increases may be due to the multiple effects of BnaC9.SMG7b as well as to other genes. Further sequence analysis showed that the BnaC9.RINGb gene in the qSS.C9 mapping region may be directly involved in the regulation of seed development. On this basis, the candidate genes in the qSS.C9 region were analyzed by comparing genomics and molecular biology. The main results were as follows: 1. BnaC9.SMG7b gene complementation test showed that BnaC9.SMG7b gene had no significant effect on 1000-grain weight. This suggests that there may be other genes that regulate the 1000-grain weight of NILY106. Candidate gene analysis: comparing and sequencing the candidate genes in the qSS.C9 mapping region, we found that BnaC9.RINGb was significantly different between the parents, and the preliminary transgenic complementary test showed that BnaC9.RINGb gene negatively regulated 1000-grain weight, and BnaC9.RINGb gene was negative regulated by BnaC9.RINGb gene. The 1000-grain weight of the receptor material HZ396 was significantly decreased, probably the target gene .3.BnaC9.RINGb homologous copy analysis. Sequence alignment showed that the BnaC9.RINGb gene had one homologous gene in Arabidopsis thaliana, eight in Brassica napus and three in Brassica napus. There are 3. 4. The gene was expressed in the cotyledons, leaves, hornaceous pericarp, pistil and stamen of Arabidopsis thaliana. The subcellular localization indicated that the expressed protein was located in the nucleus. Studies on the function of homologous genes in Arabidopsis thaliana: the length, width and number of kernels per pod of some ring mutants were significantly higher than those of wild type. The 1000-grain weight of the mutant was higher than that of wild type, but it did not reach the significant level.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S565.4

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