【作者】 龙海；

【导师】 郑有良；

【作者基本信息】 四川农业大学 ， 作物遗传育种， 2006， 博士

【摘要】 小麦LMW-GS是重要的种子贮藏蛋白，与品质关系密切。本文在对小麦LMW-GS基因克隆的基础上，结合已有信息对LMW-GS基因家族进行了分类与染色体定位，并针对各类基因开发染色体组特异性分子标记。主要研究结果如下： 1．小麦LMW-GS基因的分子克隆 根据已知LMW-GS基因保守序列设计引物，采用PCR法从小麦品种川农16、川麦42以及中国特有西藏半野生小麦中克隆了6个LMW-GS新基因：LMWCN16-1、LMWCN16-2、LMWCM42-1、LMW908-1、LMW908-2及LMW908-3，其基因登录号分别为AY296752、AY296753、DQ415644、AY299458、AY299457及AY299459，其中LMWCN16-1和LMW908-3由于存在提前终止密码子，推测为假基因。LMWCN16-2和LMW908-1中与已知LMW-GS的主要差异为部分位置的氨基酸替换，而LMWCM42-1和LMW908-2则与已报道的LMW-GS基因及预测蛋白的一级结构存在较大差异，可能对谷蛋白多聚体形成有一定影响。 2．LMW-GS基因的类群划分与染色体定位 通过对从数据库下载的69个LMW-GS基因进行推导氨基酸序列比对及聚类分析发现，根据其高度保守的N末端推导氨基酸序列，可将这69个基因划分成9种类群。根据DNA序列比对结果，针对各类基因共设计了11对引物，利用中国春第1同源群双端体系的总DNA进行PCR扩增来对各类基因进行染色体定位分析。结果发现，9对引物为LMW-GS基因类群特异性引物。9类基因都具有唯一的染色体位置，其中3类基因位于染色体1AS上，2类基因位于1BS上，而染色体1DS上分布有4类更多还原

【Abstract】 The wheat low-molecular-weight glutenin subumts (LMW-GS) are among the major components of the wheat seed storage proteins and are close associated with wheat quality.In the present study, we attempt to isolate novel LMW-GS gene clones from wheat. On the basis of the sequence information, the known LMW-GS genes are divided into groups and their chromosome locations are also determined. The genome specific markers, which are also specific to each of LMW-GS gene groups, have been subsequently developed. One of these markers is subjected to detect length variations of LMW-i genes in A-genome diploid wheats.The main results are presented as following:1. Molecular Cloning of LMW-GS Genes from WheatBased on the conserved sequences of the known LMW-GS gene, a primer set was constructed for PCR cloning of LMW-GS genes from wheat cultivar ’Chuannong 16’, ’Chuanmai42’ and one accession of T.aestevum ssp.tibet shao. Six novel LMW-GS genes, AY296752 (LMWCN16-1), AY296753 (LMWCN16-2), DQ415644 (LMWCM42-1), AY299458 (LMW908-1), AY299457 (LMW908-2) and AY299459 (LMW908-3) were isolated, among which LMWCN16-1 and LMW908-3 are putative pseudogenes due to the presence of in frame stop condons. The differences between LMWCN16-2, LMW908-1 and known LMW-GS are the substitutions of amino acids. However, LMWCN16-2 and LMW908-2 have significant difference on sequence and structure, and thus possess the potential effects on the formation of the glutenin polymers.更多还原