DISSERTATION RESEARCH: Evolutionary Genetics of Flowering Time Variation in Helianthus

论文研究：向日葵开花时间变异的进化遗传学

• 批准号: 0608118
• 负责人: Loren Rieseberg
• 金额: $ 1.2万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0608118&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Evolutionary; Genetics; Flowering

The research will investigate the genetic basis of an important developmental and reproductive trait, flowering time, and its responsiveness to an environmental cue, daylength, in annual sunflowers. Sunflowers exhibit an extraordinary diversity of daylength responses, and notably, changes in daylength response coincide with domestication, clinal variation in natural populations, and speciation. Conserved and novel aspects of gene and protein regulation in the developmental pathway that measures daylength will be assessed. Association of flowering time gene expression and daylength response will be measured in 1) domesticated sunflower, 2) wild populations of Helianthus annuus along a latitudinal cline, and 3) between a hybrid species and its two parent taxa. Whether sunflower copies of flowering time genes are located in genomic regions known to influence flowering will also be determined. Based on these results, the best candidate genes will be sequenced across several domesticated lines, Native American landraces, and wild populations of several sunflower species to ask whether and in which lineages these genes experienced positive selection. The project will identify genes involved in domestication, adaptation, and speciation, and connecting the evolutionary genetics underpinning a remarkably labile trait to a well-studied developmental pathway may provide new insights into the features of pathway architecture or gene regulation that facilitate evolution. Diagnostic tools for detecting sequence and expression variation of key flowering time genes will be developed for an important agricultural species. In addition, these resources will aid in conservation of a federally listed threatened species, and the project may identify genetic variation important for persistence of this species.

该研究将调查一年生向日葵的一个重要发育和生殖特征——开花时间及其对环境线索——日长——的反应的遗传基础。向日葵的日长响应具有极大的多样性，值得注意的是，日长响应的变化与驯化、自然种群的临床变异和物种形成相一致。将评估测量日长发育途径中基因和蛋白质调控的保守和新颖方面。研究了1)驯化向日葵、2)沿纬度梯度的野生向日葵种群以及3)杂交种与其两个亲本类群之间开花时间基因表达与日长响应的关系。向日葵开花时间基因的拷贝是否位于已知影响开花的基因组区域也将被确定。基于这些结果，最佳候选基因将在几个驯化系，美洲本土品种和几个向日葵物种的野生种群中进行测序，以了解这些基因是否以及在哪些谱系中经历了积极的选择。该项目将识别与驯化、适应和物种形成有关的基因，并将支撑一个非常不稳定特征的进化遗传学与一个得到充分研究的发育途径联系起来，可能为促进进化的途径结构或基因调控的特征提供新的见解。将开发用于检测重要农业物种开花时间关键基因序列和表达变异的诊断工具。此外，这些资源将有助于保护联邦政府列出的受威胁物种，该项目可能会确定对该物种持续存在重要的遗传变异。