一个水稻花时提前突变体的遗传分析与基因定位

发布时间：2018-07-12 14:12

本文选题：水稻 + 花时提前　；参考：《四川农业大学》2016年硕士论文

【摘要】：水稻作为世界上最为重要的作物之一,其发展状况与粮食安全密切相关。杂交水稻的大面积推广对我国乃至世界农业生产做出了巨大贡献,但生产成本一般高于常规稻,特别是农民的购种费用逐年升高。提高单位面积繁殖制种产量是有效降低杂交稻种子生产成本的关键,而在诸多影响繁殖制种产量的因素中,母本开花习性、父母本花时相遇是一个重要影响因素。因此通过寻找到能够调控水稻一天中开花时间的基因对于提高水稻异交结实率具有重要意义；此外,随着全球气候变暖,高温天气对水稻产量将产生巨大影响,寻找控制水稻一天当中开花时间的基因,选育水稻花时提前新品种以避开午间高温危害,从而达到提高结实率的目的。因此,我们通过EMS诱变籼稻品种宜香1B,从M2代中筛选到了一份开花时间显著提前的突变体(emf1)。本研究对该突变体进行了突变性状鉴定,遗传分析,基因定位相关工作,为克隆花时提前基因奠定了坚实的基础,主要研究结果如下：1.突变体表型与农艺性状分析在相同的田间生长条件下,与野生型相比,突变体除了分蘖数有所减少外,其最明显的差异在于每天开颖散粉时间提前了约1-1.5h。田间调查显示,野生型与突变体开花习性因当天气温而异,野生型花时分散,开花历时较长,低温下常出现部分不开颖现象,而突变体花时集中,开花历时短,较低温度下也能正常开花。2.浆片结构及生理特征分析形态观察发现,突变体小花开颖前3h与开颖中的浆片均分别大于野生型小花的浆片,同时突变体浆片吸水膨胀速率快于野生型浆片。0.3%12-KI溶液对浆片染色,在开颖前突变体和野生型浆片中观察到较多的蓝色颗粒,开颖中突变体和野生型浆片中蓝色颗粒较少,无论开颖前与开颖中,突变体浆片中蓝色颗粒都多于野生型。测定浆片中可溶性糖含量发现,突变体和野生型开颖前后浆片中可溶性糖含量均有所增加,但开颖前与开颖中突变体浆片中可溶性糖含量均高于野生型浆片中可溶性糖含量,表明突变体在开花过程中浆片中较多的可溶性含量能够为水稻小花提供更多的能量促进水稻的开颖,使其开花时间提前。3.突变体的遗传分析emfl突变体与其对应野生型宜香1B杂交,获得的F1表现为正常的野生型花时性状,说明该性状为隐性遗传。F2群体的正常花时与早花时植株的分离比接近3：1,说明该花时提前性状受1对等位隐性基因控制。4.基因定位结果以emfl/02428的F2分离群体作为初定位群体,首先利用实验室已有的520多对SSR和Indel分子标记,将突变基因初步定位为1号染色体的标记1-8和osl-107.6之间。进一步利用256个隐性单株将基因定位到一号染色体长臂的158kb的区间内,在该染色体区域内,尚未有关于花时提前基因的定位或克隆,故推测本研究定位的基因为一个花时提前相关的新基因,暂时命名为emfl。
[Abstract]:As one of the most important crops in the world, rice development is closely related to food security. The extensive popularization of hybrid rice has made a great contribution to agricultural production in China and the world, but the production cost is generally higher than that of conventional rice, especially the cost of seed purchase by farmers increases year by year. Increasing seed production per unit area is the key to effectively reduce the cost of seed production of hybrid rice. Among the factors that affect the yield of hybrid rice, the flowering habit of female parent and the meeting of parents are important factors. Therefore, it is important to find genes that can regulate the flowering time of rice during the day to increase the rate of cross-breeding. In addition, as the global climate warms, the high temperature weather will have a great impact on rice yield. To search for genes to control the flowering time of rice in a day and to select new varieties in advance of anthesis in order to avoid the harm of midday high temperature so as to increase the seed setting rate. Therefore, a mutant (emf1) with significantly earlier flowering time was screened from M2 generation by EMS mutagenesis of indica rice variety Yixiang 1B. In this study, the mutant was identified, genetic analysis and gene mapping related work, which laid a solid foundation for the cloning of genes in advance of flowering. The main results are as follows: 1. Analysis of mutants and agronomic characters under the same field growth conditions and wild type, the most obvious difference was that the opening and dispersing time of the mutants was about 1-1.5 hours earlier than that of the wild type in addition to the number of tillers. Field investigation showed that the flowering habits of wild type and mutant varied with the temperature of the day, the flowering time of wild type was dispersed, the flowering duration was longer, and some of them did not open glume at low temperature, while the mutant had concentrated flowering time and short flowering duration. Normal flowering. 2. 2. The morphological analysis of pulp structure and physiological characteristics showed that the size of the mutant was higher than that of wild-type floret 3 h before floret opening, and the water swelling rate of the mutant was faster than that of wild-type pulp. More blue granules were observed in the protuberance variant and wild type plasmas, but there were fewer blue granules in the open mutant and wild type, both before opening and in the open glume, the blue particles in the mutant were more than that in the wild type. It was found that the soluble sugar content of mutant and wild type was increased before and after opening, but the content of soluble sugar before and after opening was higher than that in wild type. The results showed that the soluble content of the mutant during flowering could provide more energy for rice floret to promote the opening of rice glume and advance the flowering time by 3. 3%. Genetic Analysis of the emfl Mutant and its corresponding Wild Type Yixiang 1B, F1 obtained showed normal wild-type anthesis traits. The segregation ratio of normal and early flowering plants was close to 3: 1, which indicated that the early anthesis trait was controlled by a pair of allelic recessive genes. The result of gene mapping was based on the F2 segregated population of emfl/02428. Firstly, the mutation gene was preliminarily located between marker 1-8 and osl-107.6 on chromosome 1 by using more than 520 pairs of SSR and Indel molecular markers. Furthermore, 256 recessive individual plants were used to locate the gene in the region of 158kb with a long arm of chromosome 1, in which there was no mapping or cloning of the gene in advance of flowering. Therefore, we speculated that the gene located in this study was a new gene related to anthesis in advance, and was tentatively named emflon.
【学位授予单位】：四川农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S511;Q943.2

【参考文献】