东乡野生稻耐低磷性状的遗传与分子机制研究

Available phosphorus deficiency severely in soil is a major limiting factor for rice production. And the non-renewable phosphate rock will be exhausted. Therefore, it is one of the most important issues on investigation and utilization of phosphorus-deficiency tolerance genes from wild rice, which would provide some important theory and practice value direction for development rice variety with phosphorus-deficiency tolerance. And it is a very important strategy for relieving the shortage of phosphorus resources..Based on our previous researches, backcross inbred lines population BC1F10 and BC4F6 is used to establish and improve the evaluation system of low phosphorus tolerance. SSR markers are used to study the genetic character and QTL mapping of phosphorus-deficiency tolerance in Oryza rufipogon. In order to achieve fine mapping of major QTL qPU-2DX controlling phosphorus uptake, numbers of makers (SNP and CAPs) and fine mapping population will be developed. The fine mapping population will be constructed through the nearly isogenic line (NIL) D107 cross with recurrent parent (O. sativa L. cv. Xieqingzao B). Subsequently, qPU-2DX cloning and function analysis will be investigated by microarray, quantitative RT-PCR, southern blot, et al. These detailed results would illuminate the gene expressions pattern of phosphorus-deficiency tolerance genes and its action mechanism. Our researches in the present study would helpful for us understanding the genetic and molecular mechanisms of phosphorus - deficiency tolerance. It would also provide some very important molecular information for further investigation and utilizations on phosphorus - deficiency tolerance genes in O. rufipogon.

土壤有效磷含量严重匮乏和磷矿石资源即将耗竭是限制水稻生产的重要因素。挖掘与利用近缘野生稻磷高效利用基因，培育耐低磷新品种是解决磷资源短缺的最重要途径，具有重要的理论和实践价值。.本项目在前期研究的基础上，以回交、自交重组自交系BC1F10和BC4F6为试材，建立和完善东乡野生稻耐低磷评价体系；利用SSR分子标记研究东乡野生稻耐低磷性状的遗传规律及相关基因的QTL定位。同时，利用耐低磷近等基因系D107构建精细定位群体，获得大量SNP、CAPs标记，对东乡野生稻磷高效利用主效QTL位点qPU-2DX进行精细定位；随后利用基因芯片、实时荧光定量PCR和Southern Blot等技术，克隆和鉴定qPU-2DX磷高效利用基因，揭示其在低磷胁迫下的表达模式和作用机制。本项目研究有助于全面阐明东乡野生稻耐低磷性状的遗传机理和分子机制，同时对挖掘与利用东乡野生稻磷高效利用基因具有重要的指导意义。

磷是植物生长和发育的必须的第二大元素。土壤有效磷含量严重匮乏和磷矿石资源即将耗竭是限制水稻生产的重要因素。挖掘与利用近缘野生稻磷高效利用基因，培育耐低磷新品种是解决磷资源短缺的最重要途径，具有重要的理论和实践价值。. 本项目在前期研究的基础上，以回交、自交重组自交系BC1F10和BC4F6为试材，建立了东乡野生稻耐低磷评价体系；鉴定获得17个耐低磷渐渗系。利用SSR和InDel分子标记成功构建了东乡野生稻耐低磷性状的遗传图谱，结合遗传群体的耐低磷的表型数据进行QTL分析，检测到22个QTL耐低磷相关位点，有8个位点的贡献率大于20%。. 采用cDNA-AFLP和实时荧光定量PCR分析技术，分析和验证了东乡野生稻和耐低磷渐渗系幼苗期应答低磷胁迫的差异表达谱特征，克隆测序获得50个差异表达基因片段TDFs (Transcript derived fragments)，通过Blast比对和功能分析，将TDFs分为8类。基于东乡野生稻和协青早B高通量测序的数据，本研究进一步开发了一批SSR标记和InDel标记，实现了东乡野生稻遗传图谱加密及精细定位；利用转录谱测序和实时荧光定量PC等技术，分析鉴定了东乡野生稻耐低的分子调控网络及分子机制，获得了11个耐低磷候选基因，探明了其在不同时期不同试材中的基因表达模式和特征；克隆了其中的2个候选基因，分析了其功能。本项目研究有助于全面阐明东乡野生稻耐低磷性状的遗传机理和分子机制，同时对挖掘与利用东乡野生稻磷高效利用基因具有重要的指导意义。