A Genomic Analysis of Complex Trait Variation in Mimulus

描述（由申请人提供）：群体遗传学的主要目标是确定遗传变异的性质以及它如何在自然群体中保持。杜鹃是一种野花，在花大小上表现出大量的遗传变异，这一特征在物种复合体中广泛进化。我们将绘制一个自然种群中导致花大小变异的遗传位点，并确定等位基因对一系列植物性状的影响程度和分布。本实验将评估QTL的显性程度和模式，以及与花大小等位基因相关的多效效应。简化的育种方案将产生近等基因系（NILs），这对于确定重要QTL的实际位点的定位克隆是必要的。它们还将用于田间和实验室研究，以测量个体QTL尺度上花大小变化的直接适合度结果。这些数据将用于检验关于花大小变化的选择性维持的假设。结合以往和正在进行的研究结果，这些实验将提供一个详细的比较在种间和种内的花形态的变化在M. guttatus物种复合体。定位克隆重要的花系qtl将为生态学上重要基因的分子群体遗传研究提供可能。拟议的研究将对教育和科学资源的发展产生更广泛的影响。

DESCRIPTION (provided by applicant): A primary objective of population genetics is to determine the nature of genetic variation and how it is maintained in natural populations. Mimulus guttatus is a wildflower that exhibits substantial genetic variation in flower size, a trait that has evolved extensively within the species complex. We will map the genetic loci responsible for variation in flower size within a single natural population of M. guttatus and determine the magnitude and distribution of allelic effects on a range of plant characters. The experiments will estimate the extent and pattern of dominance at QTL and the pleiotropic effects associated with flower size alleles. A streamlined breeding scheme will produce Nearly Isogenic Lines (NILs), necessary for positional cloning of the actual loci defining important QTL. They will also be used in field and lab studies to measure the direct fitness consequences of flower size variation at the scale of individual QTL. These data will be used to test hypotheses regarding the selective maintenance of flower size variation. Combined with results from previous and ongoing studies, these experiments will provide a detailed comparison of inter- and intra- specific variation in floral morphology within the M. guttatus species complex. Positional cloning of important floral QTLs will allow molecular population genetic studies of ecologically important genes. The proposed research will have broader impacts thorough both education and the development of scientific resources.