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

1. 利用以下水稻群体对白核和粒级进行了遗传分析。5个品种间双列杂交产生的f1群体，用于酿造清酒和煮饭。- Gohyakumangoku与Koshihikari之间的fl、F2和回交群体。此外，利用孝北石木和日本裸的重组自交系进行了白核和籽粒大小的QTL分析。结果，这些性状的主要qtl在染色体2和12.2上被检测到。为了鉴定控制清酒酿造有用性状的基因，采用SAGE方法对山田石木（酿酒米）和Reiho（煮米）的成熟种子进行了基因表达分析。其中一个表现出很强的品种特异性表达的候选基因是Rsg1，它编码13kda的prolamin。基于基因结构分析，Reiho保留了完整的Rsg1基因，而Yamadanishiki由于插入了转座子样序列而具有失活基因。用91个双单倍体株系Yamadanishiki和Reiho进行种子蛋白含量QTL分析，在第12染色体上检测到1个13 kDa prolamin蛋白含量QTL，表明该位点与Rsg1基因对应。对188个清酒粳稻品种的76个SSR位点的等位基因多样性进行了分析。在此基础上，采用马尔可夫链蒙特卡罗方法进行了主成分分析、聚类分析和群结构分析。将188个品种划分为10个亚群。其中，三个类群（命名为Yamadanishiki， Gohyakumangoku和Hanafubuki）被发现构成了大多数酿造清酒的水稻品种。

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.