Linking Rice, Arabidopsis and the Grasses to Explore Natural Genetic Variation

将水稻、拟南芥和禾本科植物联系起来探索自然遗传变异

• 批准号: 0110004
• 负责人: Susan McCouch
• 金额: $ 135.68万
• 依托单位: Cornell Univ - State: AWDS MADE PRIOR MAY 2010
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0110004&HistoricalAwards=false
• 关键词: Linking; Rice; Arabidopsis; Grasses; Explore

To date, the map-based cloning and characterization of genes from crop species has largely been limited to monogenic traits, such as those providing disease resistance, that are controlled by single genes causing clear phenotypic effects. Most agronomically-important traits, such as yield and yield components, however, are polygenic traits controlled by multiple genes and influenced by the environment. Over the past decade, the application of molecular markers and genetic linkage maps has allowed specific regions of the genome controlling polygenic traits, called quantitative trait loci (QTLs), to be identified in all of the major crop species. In spite of the wealth of positional information for these regions, however, few genes underlying quantitative traits have actually been cloned. As a result, many questions concerning the nature and function of these genes, as well as the molecular mechanisms behind the genetic variation of agronomically-important traits, remain unanswered. The genes underlying QTLs derived from a wild rice ancestor (O. rufipogon) that are associated with natural variation for flowering time, grain weight, and plant height in elite cultivated material will be identified and characterized. Three QTLs that map to rice chromosome 1, one of the first rice chromosomes to be completely sequenced, will be targeted. The specific objectives are to fine-map major QTLs for flowering time, grain weight, and plant height, then to isolate candidate genes that are located within those regions and, finally, to demonstrate phenotypic complementation via transformation with genes underlying the QTLs. The sequence variation from orthologs of the genes underlying the target QTLs in wild and cultivated Oryza, other grasses, and Arabidopsis will be compared to gain an evolutionary perspective and insight into functionally-important conserved domains. This work will generate significant new information about the identity and functional significance of genes associated with agronomically-important traits in the grasses and will test a multi-faceted strategy for rapid identification of genes underlying QTLs when genomic sequence is available in the target region.

迄今为止，基于图谱的作物物种基因克隆和表征在很大程度上仅限于单基因性状，例如提供抗病性的性状，这些性状由单个基因控制，导致明显的表型效应。然而，大多数农艺重要性状，例如产量和产量组成部分，都是受多个基因控制并受环境影响的多基因性状。在过去的十年中，分子标记和遗传连锁图谱的应用使得控制多基因性状的基因组特定区域（称为数量性状基因座（QTL））在所有主要作物物种中得以识别。然而，尽管这些区域的位置信息丰富，但实际上克隆数量性状背后的基因却很少。因此，有关这些基因的性质和功能以及农艺重要性状遗传变异背后的分子机制的许多问题仍未得到解答。来自野生稻祖先（O. rufipogon）的 QTL 基因将被鉴定和表征，这些基因与优良栽培材料中的开花时间、粒重和株高的自然变异相关。定位到水稻 1 号染色体（首批完成测序的水稻染色体之一）的三个 QTL 将成为目标。具体目标是精细绘制开花时间、粒重和株高的主要 QTL，然后分离位于这些区域内的候选基因，最后通过与 QTL 下的基因进行转化来证明表型互补。将比较野生和栽培稻、其他禾本科植物和拟南芥中目标 QTL 的基因直向同源物的序列变异，以获得进化视角并深入了解功能重要的保守域。这项工作将产生关于与草类重要农艺性状相关的基因的身份和功能意义的重要新信息，并将测试当目标区域中存在基因组序列时快速鉴定 QTL 基础基因的多方面策略。