【作者】 梁鑫星；

【导师】 王建飞；

【作者基本信息】 南京农业大学 ， 作物遗传育种， 2011， 硕士

【摘要】 水稻作为人类最主要的食物来源之一,其颖花发育结果直接影响其产量和品质,因此,水稻花器官特别是与产量、品质密切相关的雌雄蕊和内外稃的相关基因研究就具有十分重要的现实意义。水稻的花器官从外至内包括了1片外稃、1片内稃、2枚浆片、6枚雄蕊以及1个雌蕊(1个子房和2个柱头),此外,其基部还有2片退化的颖片以及2片护颖。与双子叶植物花器官发育研究相比,水稻等单子叶植物的相关研究还相对滞后,研究者们利用双子叶植物发育基因的保守序列对水稻的基因组文库以及cDNA文库进行筛选,获得了很多MADS-box基因,但由于缺乏与性状的联系,大多数基因的确切功能无法明确。利用花器突变体研究花发育相关基因更能直接地明确基因功能。在籼稻品种93-11的Y射线辐照诱变处理后代中,我们发现了1株内稃发育不完全的突变体材料pd1,突变体经多代不同环境自交种植,确认该突变性状能够稳定遗传。本研究对该突变体进行了花器官结构的解剖、观察,相关突变性状的遗传分析,相关基因的精细定位研究,以及候选基因预测,其主要结果如下：(1)花器官结构观察：突变体颖花的1个外稃、2枚浆片和1个雌蕊等均发育正常。但1个内稃发育不良,呈现短小的类叶片状,致使整个小花弯曲；雄蕊数目减少为4枚；花粉育性、结实率和千粒重明显下降。(2)水稻颖花内稃突变体的遗传分析：在抽穗期,对突变体pdl与苏御糯杂交的F1代和F2代植株进行观察、调查。结果表明,F1代植株的小花发育正常,表明该性状为隐性性状。对F2代性状调查结果进行χ2测验(χ2c<χ20.05=3.84),正常株数目与内稃发育突变株数目的比例符合3：1分离比,表明了该突变性状是受1对隐性基因控制的。(3)突变体相关基因的精细定位：利用图位克隆方法,以突变体pd1与苏御糯构建的F2代以及pd1与日本晴、热研构建的F2代、F3代作为定位群体,运用SSR标记将PD1基因定位于第1染色体着丝粒下方的RM11239-RM11245之间约69Kb物理区间。(4)PD1候选基因预测：检索水稻基因组序列,目标区间共有10个开放阅读框(ORF),其中6个预测基因具有表达信息。LOC_Os01g40120为LYAR-type C2HC zinc finger结构的基因,仅在花中表达,最终确定LOC_Os01g40120作为候选基因的首选将作进一步功能研究。更多还原

【Abstract】 As one of the popular food for human beings, the glume flower development results of rice influences its yield and quality. Consequently, the research of stamen、pistil、lemma and palea genes for rice flower development especially related to yield、guality is with very important practical significance.The floral organ of rice, which belongs to gramineae monocot, includes 1 lemma、1 palea、2 lodicules、6 stamen and 1 pistil (1 ovary and 2 stigmas), besides, the basal of floral organ has 2 degenerative glumes and 2 protective glumes.Compared to the research of floral organ development model of the dicot, the research of floral organ development model of monocot is backward. Rresearchers are screeneing the rice’s genomic library and cDNA library by the conserved sequence of monocot development genes, and have got lots of MADS-box genes. However, because of lacking of points of junction for characters, the exact function of majority genes are not sure. Using floral organ mutations in research of genes for flower development is more effective.In the Y ray irradiation mutagenic treatment progenies of rice varieties 93-11, we found 1 mutation with ateliosis palea and its mutant character is genetic stability in the different environmental multiple generational self-cross planting. The research has done genetic analysis of mutant character of the mutation, anatomical observation of its flower structure, fine mapping of related gene, and prediction of candidate genes, main results are as follows:(1) Anatomical observation floral structure:except 1 lemma、2 lodicules and 1 pistil of the normal rice glume flower, the mutation glume flower has 1 dysplasia bladed palea, which causatives the flower bending; the number of stamen decreased to 4 only; pollen fertility、seed setting rate and 1000-grain weight decreased significantly.(2) Genetic analysis of rice glume palea mutation:in the heading stage, we have done observation and inverstigation of F1/F2 population which from pd1 and Suyunuo. As a result, the flowers of F1 population have normal phenotype, so it’s recessive phenotype. Afterχ2 testing(x2c<x20.05=3.84) of the F2 population characters investigation, the proportion for the number of normal plants and the palea development mutation conforms to segregation ratio 3:1, which shows that the mutant character is being controlled by 1 pair recessive genes.(3) Fine mapping of related gene:by based cloning, using F2 population from pd1 and Suyunuo; F2 population and F3 population from pd1 and Nipponbare、Reyan, we have fine mapped the related gene PD1 in a 69Kb interval between RM11239 and RM11245 under the centromere of Chrl.(4)Prediction of candidate genes of PD1:after searching the genomic sequence, there are 10 ORFs in the target interval,6 of them have expression information. LOC_Os01g40120 only express in flower, and has domain LYAR-type C2HC zinc finger. So, LOC_Os01g40120 has been determined as the first candidate gene for further functional research.更多还原