Identification of genetic factors controlling useful traits for Sake-brewing and development of evaluation methods on genetic resources of Sake-brewing rice

1.使用以下水稻群体进行白色心和谷粒大小的遗传分析。F1群体产生于五个品种之间的杂交，用于清酒酿造和烹饪大米。此外，利用猪北锦与日本晴的重组自交系对白色心粒和籽粒大小进行了QTL分析。结果表明，这些性状的主效QTL位于第2和12.2染色体上。为了鉴定控制清酒酿造有用性状的基因，用SAGE方法对山田锦（清酒酿造稻）和菱穗（烹饪稻）的成熟种子进行了基因表达调查。其中一个候选基因表现出强烈的品种特异性表达是Rsg1，其编码13 kDa的醇溶蛋白。基于基因结构分析，发现Reiho保持完整的Rsg1基因，而Yamadanishiki由于插入转座子样序列而具有失活的Rsg1基因。利用山田锦和菱穗间的91个双单倍体材料对籽粒蛋白质含量进行了QTL分析，在第12染色体上检测到1个13 kDa醇溶蛋白含量的QTL，该位点与Rsg1基因相对应.利用76个SSR标记对188个日本清酒酿造稻和食用稻品种进行了遗传多样性分析。在此基础上，进行了主成分分析、聚类分析和组结构分析（用马尔可夫链蒙特卡罗方法）。将188个品种分为10个亚类。其中，三个组（命名为山田西木，五叶满国和花风木组）被发现由大部分的清酒酿造大米品种。

1. Genetic analysis on white core and grain size was carried out using the following populations of rice.-F1 populations generated from diallel crosses between five cultivars for Sake-brewing and cooking rice.-Fl, F2 and backcross populations between Gohyakumangoku and Koshihikari.In addition, QTL analysis on white core and grain size was performed using recombinant inbred lines between Hyogokitanishiki and Nipponbare. As a result, major QTLs for these traits were detected on chromosomes 2 and 12.2. In order to identify the genes controlling useful traits for Sake-brewing, gene expression survey was carried out by SAGE method with ripening seeds of Yamadanishiki (Sake-brewing rice) and Reiho (cooking rice). One of the candidate genes showing strong variety-specific expression was Rsg1 which codes 13 kDa of prolamin. Based on the gene structural analysis, Reiho was found to keep intact Rsg1 gene, whereas Yamadanishiki has inactive one because of the insertion of transposon-like sequences. QTL analysis on seed protein content was also carried out using 91 double haploid lines between Yamadanishiki and Reiho, and one QTL for protein content of 13 kDa prolamin was detected on chromosome 12, suggesting this locus correspond to Rsg1 gene.3. Allelic diversity at 76 SSR loci among 188 cultivars of Sake-brewing and cooking rice was examined. Based on these data, principal component analysis, cluster analysis and group structural analysis (by Markov Chain Monte Carlo Method) were carried out. As a result, 188 cultivars were classified into 10 subgroups. Of these, three groups (named as Yamadanishiki, Gohyakumangoku and Hanafubuki groups) were found to consist of majority of Sake-brewing rice cultivars.