Application of new technologies to rice breeding

将细胞融合和基因操作等新技术应用到水稻育种中，不仅需要积累水稻分子水平的知识，还需要改进组织培养技术。在获得基因操纵的植物之后，还需要一个有效的改良新品种的选择系统。建立了与水稻贮藏蛋白、谷蛋白和蛋白合成有关的poly <(A)^+> RNA cDNA文库。结果表明，乳内贮藏蛋白形成了<I>和<II>两种颗粒状结构，而<I>不可消化蛋白主要由脯蛋白2组成。建立了水稻叶绿体DNA物理图谱，确定了Rubisco大亚基和atp酶亚基的基因位置。测定了基因的碱基序列。在有丝分裂DNA上，成功克隆了所有DNA片段，并发现了一个具有自主复制序列活性的片段。利用多个品种对种子和花粉诱导愈伤组织的不定芽形成和体细胞胚发生进行了研究，明确了植株再生的基因型变异。在此基础上，通过种子愈伤组织原生质体诱导植株再生。分析了从细粒突变体后代中获得的突变基因的特征，明确了该基因作为诱变原的强烈作用。用亚硝基化合物处理受精卵细胞获得了新的含糖和萎缩的突变体。研究了dee -geo- woogen型半矮秆在节间伸长中的基因表达，并分析了其相关性状的抗旱性和蒸煮品质的表型表达。

For the application of new technologies such as cell fusion and gene manipulation to rice breeding, it is necessary to accumlate the knowledges of molecular level in rice plants and also to improve the technologies in tissue culture. After getting gene-manipulated plants, an efficient selection system for improving to a new variety should be required.1. The cDNA library on poly <(A)^+> RNA which related to the synthesis of rice storage protein, glutelin and prolamin, was established. It was clearified that the storage protein in endosperm formed two kinds of granules, protein body <I> and <II> , and nondigestable protein body <I> mainly consisted prolamin.2. A physical map of rice chloroplast DNA was established and the location of the genes for large subunit of Rubisco and the subunits of ATPase was proved. The base sequences of the genes were also determined. On the mitocondorial DNA, cloning of all DNA fragments was succeeded and a fragment having activity of autonomously replicating sequence was found out.3. Adventive shoot formation and somatic embryogenesis from callus induced from seeds and pollen were investigated using many varieties, and genotypic variability in plant regeneration was clearified. On the basis of the results, plant regeneration was succesively induced from protoplasts originated from seed callus.4. Characteristics of mutator gene obtained from progenies of slender grain mutant was analyzed and strong effect of the gene as amutagen was clearified. New sugary and shrunken mutants were obtained by treating fertilized egg cells with nitroso compounds.5. Gene expression of semi-dwarfness of Dee-geo-woo-gen type was investigated in internode elongation, and also phenotypic expression of drought resistance and cooking quality were analyzed in their related characters.