Molecular Genetical Basis of the Establishment of Crop Species

本研究的最终目的是从分子遗传学的角度对作物物种及其野生祖先进行比较，并阐明作物物种成功建立的分子基础。本研究共开展了三个方面的研究工作，主要结果如下：构建了作物及其近缘基因的DNA文库，构建了普通小麦和水稻的基因组DNA或cDNA文库，并利用该文库建立了与所有染色体相对应的RFLP位点连锁图谱。利用这些文库的克隆作为探针，阐明了核基因组的种间关系和种内分化。构建了甜菜属植物叶绿体基因文库，并对4个甜菜属植物的叶绿体基因组进行了种间关系分析；对水稻属、普通小麦属、蚕豆属和豌豆属4个属的叶绿体基因组的…结构进行了研究从rDNA的拷贝数、转录活性和基因间隔区的结构等方面比较了野生种和栽培种的NO区更多的e和功能活性。根据这些结果，推测了栽培种的起源和系统发育分化。烟草中含有两个psbD蛋白基因，每个基因都来自烟草的两个祖先N和N。对烟草几个重要的经济性状，控制种子休眠、萌发和穗萌发的遗传因素进行了分析，并鉴定了它们的转录产物。从水稻籽粒和甘薯块茎中分离了几个贮藏蛋白基因，并测定了它们的全序列，在此基础上对它们的功能和进化关系进行了讨论。分离了与萝卜衰老和拟南芥热激相关的几个基因，并确定了它们的结构。较少

The final objectives of the present research are to compare crop species and their wild ancestors from the molecular genetical viewpoint and to clarify the molecular basis on which crop species have been successfully established. Three lines of the researches were carried out, of which main results are outlined as follows :Construction and utilization of DNA libraries of crops and tneir relatives ; In common wheat and rice genomic DNA or cDNA library was constructed, using which the linkage maps of RFLP sites corresponding to all chromosomes were established. Using the clones of these libraries as probes, interspecific relationships as well as intraspecific differentiation of the nuclear genome have been clarified. In the genus Beta chloroplast DNA library was constructed, and interspecific relationships among the chloroplast genomes of four Beta species were determined.Studies on several characters of the basic importance ; In four genera, Oryza, Triticum, Vicia and Pisum the structur … More e and functional activity of the NO regions were compared between the wild and cultivated species as to the copy number of rDNA, its transcriptional activity and the structure of intergenic spacer. Based on the results, the origin of cultivated species and their phylogenetic differentiation were presumed. In tobacco, Nicotiana tabacum had two genes for psbD protein, each one of which was proved to have been derived from two progenitors, N. and N. tomentosiformis.Studies on several economically important characters ; Genetic factors controlling seed dormancy, germination and ear-sprouting were analyzed and their transcriptional products were identified. Several genes for storage proteins in rice grains and sweet potato tubers were isolated and their entire sequences were determined, based on which their functions and evolutionary relationships were considered. A few genes relating to the senescence in radish and the heat shock in Arabidopsis were isolated and their structures were determined. Less