水稻落粒基因的分子进化研究

发布时间：2018-06-03 21:57

本文选题：水稻 + 落粒基因　；参考：《东北师范大学》2017年硕士论文

【摘要】：水稻(Oryzasativa L.)是世界第三大粮食作物,全世界有超过一半以上的人口以水稻为主食。水稻隶属于禾本科(Poaceae)稻亚科(Oryzoideae)稻族(Oryzeae)。自被驯化以来,栽培水稻解决了人类食物稳定供应的基本问题。特别是在亚洲地区,栽培水稻为该地区的社会发展奠定了坚实的物质基础。在栽培水稻驯化的过程中,谷粒落粒性(seed shattering)是一个非常重要的驯化性状。该性状的丢失是水稻驯化过程中最为关键的事件之一,因为落粒性状的丢失导致谷粒在成熟后可以继续保留在穗上,以有利于种植者对成熟种子的收集。相对而言,野生水稻的种子在成熟后容易脱落,以有利于种子在自然环境中的传播。在本研究中,我们通过运用基因组重测序数据从全基因组水平统计栽培水稻及其野生亲本的遗传多样性,并在该基础上进一步分析水稻落粒性状相关基因(sh4,q SH1,SHAT1,Os CPL1,Os Sh1和SH5)的核苷酸多样性水平。本研究结果显示,在全基因组水平上,栽培水稻(π=0.00633)的核苷酸多样性比其野生亲本(π=0.00803)明显降低。在这六个与水稻落粒性状相关的基因中,sh4基因可能是最早受到选择的基因,因此其关键变异位点(G→T)迅速在所有栽培稻群体中被固定;其次,Os Sh1也在栽培稻驯化的过程中受到了人工选择,因此其遗传多样性明显降低。q SH1可能只在temperate japonica中受选择,受选择的时间可能在其与indica分化后。SH5是否受到选择还有待进一步研究。其余的SHAT1和Os CPL1虽然和落粒性状相关,但是并没有在水稻驯化的过程中受到人工选择。综上所述,本研究证实水稻落粒性状基因网络在驯化中受到不均衡的选择压力,其中sh4,q SH1和Os Sh1等基因在栽培稻驯化的过程中受到了人工选择,而其余的基因(如SHAT1,Os CPL1等)没有受到人工选择。
[Abstract]:Oryza sativa L.) It is the third largest food crop in the world, and more than half of the world's population feed on rice. Rice belongs to Oryzoideaeae (Oryzoideaeae). Since being domesticated, cultivated rice has solved the basic problem of stable food supply. Especially in Asia, the cultivation of rice laid a solid material foundation for the social development of the region. Seed shattering is a very important domestication trait in cultivated rice. The loss of this trait is one of the most important events in the process of rice acclimation, because the loss of grain dropping character leads to the grain remaining on the ear after ripening, which is beneficial to the growers' collection of mature seeds. In contrast, the seeds of wild rice are easy to fall off after maturation, so as to facilitate the transmission of seeds in the natural environment. In this study, we used genomic resequencing data to analyze the genetic diversity of cultivated rice and its wild parents from the whole genome level. On this basis, the nucleotide diversity levels of the genes associated with grain dropping traits of rice, SH _ 4H _ (4) H _ (1) H _ (1) SH _ (1) O _ (1) O _ (1) O _ (1) Sh1 and SH _ 5) were further analyzed. The results showed that the nucleotide diversity of cultivated rice (pion 0.00633) was significantly lower than that of its wild parent (蟺 0.00803) at the whole genome level. Among the six genes related to grain falling characters, the gene of Shish4 may be the first selected gene. Therefore, the key mutation site of the gene was rapidly fixed in all cultivated rice populations. Secondly, Sh1 was also artificially selected during the domestication of cultivated rice, so its genetic diversity decreased significantly. Q SH1 may only be selected in temperate japonica. Whether the selected time may be selected after differentiation from indica remains to be further studied. The other SHAT1 and Os CPL1 were not artificially selected during rice acclimation, although they were related to seed setting traits. In conclusion, this study confirmed that gene network of rice seed falling traits was under uneven selection pressure during acclimation, among which genes such as sh4q SH1 and Os Sh1 were artificially selected during domestication of cultivated rice. The other genes, such as SHAT1 Os CPL1, were not artificially selected.
【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S511

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