Dissertation Research: Genetic Basis of Flowering Date in Arabidopsis thaliana

论文研究：拟南芥开花日期的遗传基础

• 批准号: 9016146
• 负责人: Thomas Mitchell-Olds
• 金额: $ 1万
• 依托单位: University of Montana
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-02-01 至 1993-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9016146&HistoricalAwards=false
• 关键词: Dissertation; Research; Genetic; Basis; Flowering

Life history characters such as fecundity and age at first reproduction, are closely related to the ultimate survival and reproductive ability of plants. Life history traits are directly affected by artificial and natural selection and are therefore of particular concern for both plants breeders and evolutionary biologists alike. The expression of these traits is thought to be the result of many genes of small effect (quantitative trait loci or QTLs). Predictions about the rate and direction of evolutionary change depend on the number of segregating QTLs and the magnitude of their effects. The actual number of QTLs involved in quantitative variation, and the importance and prevalence of QTLs of large effect is still virtually unknown. Methods based on statistical theory have been used to estimate the minimum number of QTLs influencing a trait, and the relative magnitude of their effects, but these methods lack precision. In contrast, techniques of molecular biology and classical quantitative genetics provide a powerful means of estimating the minimum number of QTLs and their relative effects. This study will use genetic markers in Arabidopsis thaliana to answer the following questions: 1) How many QTLs control the timing of flowering? 2) Are there genes of large effect? 3) Do interactions between flowering time and other characters important to plant survival prevent genes of large effect from being important in the evolution of flowering time? Arabidopsis is the ideal organism for this study because the existing map is extraordinarily complete. The existence of naturally occurring inbred lines greatly simplifies statistical analyses. These techniques have been used with success in marker-aided selection programs for economically important traits in a few crop plants. They are powerful tools in genetic improvement programs, as well as for addressing fundamental evolutionary and genetic questions. However, these techniques have not been applied to natural plant populations. This work will provide some of the first data on the number of genes and the magnitude of genetic effects within species.

繁殖力、初繁殖年龄等生活史特征与植物的最终生存和繁殖能力密切相关。 生活史性状直接受到人工和自然选择的影响，因此受到植物育种家和进化生物学家的特别关注。 这些性状的表达被认为是许多小效应基因（数量性状基因座或QTL）的结果。 关于进化变化的速率和方向的预测取决于分离 QTL 的数量及其影响的程度。 参与数量变异的 QTL 的实际数量以及大效应 QTL 的重要性和普遍性实际上仍然未知。 基于统计理论的方法已用于估计影响性状的 QTL 的最小数量及其影响的相对程度，但这些方法缺乏精度。 相比之下，分子生物学和经典定量遗传学技术提供了估计 QTL 最小数量及其相对效应的强大方法。 本研究将利用拟南芥中的遗传标记来回答以下问题：1）有多少个QTL控制开花时间？ 2）是否存在影响较大的基因？ 3）开花时间和其他对植物生存重要的性状之间的相互作用是否会阻止具有大影响的基因在开花时间的进化中发挥重要作用？ 拟南芥是这项研究的理想生物，因为现有的地图非常完整。 自然发生的近交系的存在极大地简化了统计分析。 这些技术已成功用于一些作物植物中重要经济性状的标记辅助选择计划。 它们是遗传改良计划以及解决基本进化和遗传问题的强大工具。 然而，这些技术尚未应用于自然植物种群。 这项工作将提供一些有关物种内基因数量和遗传效应程度的首批数据。