Genetic Analysis of Natural Variation in the Control of Flowering Timing and Inflorescence Architecture in Brassica rapa

PI：C.Robertson McClung(达特茅斯学院)合作PI：Richard M.Amasino(威斯康星大学)，Cynthia Weinig(明尼苏达大学)物种的地理范围可以很广，在广泛栽培的驯化物种中尤其如此。作物物种在其纬度范围内会遇到截然不同的环境，包括不同的日长和温度。在包括白菜在内的许多植物中，昼长受生物钟的调节强烈地影响着开花时间。此外，开花时间和时钟功能都受到环境温度的影响。昼长反应、生物钟和温度反应有相当大的自然变异，这种遗传变异无疑有助于这些物种在不同的环境中茁壮成长。将这些复杂的遗传相互作用的研究扩展到作物所经历的环境中是很重要的，因为支撑开花时间的遗传机制可能与环境相互作用，并决定作物可以种植的纬度。Brassica作物提供了一个特别有吸引力的系统。首先，油菜与拟南芥亲缘关系密切，这意味着该模式系统为支持这类研究提供了强大的信息库。其次，Brassica种在形态上提供了巨大的多样性：Brassica Rapa用于种子、蔬菜和贮藏器官的栽培，而栽培的类型只代表了该属多样性的一小部分。本项目将评估白菜生物钟功能、开花时间以及花的大小和形状随日长和温度的自然变化。此外，还将研究这种变异对白菜在广泛环境范围内茁壮成长的能力的贡献。最后，这个项目将开发一个诱变的油菜种群和实验室练习，以利用这个种群进行K-12和本科教育的遗传学教学。广泛的影响：这个项目将为基本问题提供新的线索，并有可能在控制开花时间和日长反应方面增加油菜作物的价值(相当于每年10亿美元以上)。该项目还提供了本科生、博士后和博士后在定量分子和经典遗传分析方面的教育机会。此外，该项目将开发快速循环的白菜型突变体作为教育资源，在K-12和本科生水平上教授古典遗传学、分子遗传学和生化遗传学。这将扩大威斯康星州的FastPlants计划，该计划是一种已经在课堂上得到广泛接受的资源。因此，这一项目的外展方面应在国家一级得到体现。访问在此项目中产生的数据将可通过项目网站访问。所产生的种质将根据要求以及通过拟南芥生物资源中心提供。

PI: C. Robertson McClung (Dartmouth College)Co-PIs: Richard M. Amasino (University of Wisconsin), Cynthia Weinig (University of Minnesota)The geographic range of species can be broad, and this is particularly true among domesticated species that are widely cultivated. Crop species encounter widely differing environments, including variable daylength and temperature, across their latitudinal ranges. In many plant species, including Brassica rapa, daylength modulated by the circadian clock strongly affects flowering time. In addition, both flowering time and clock function are influenced by ambient temperature. There is considerable natural variation to the daylength response, the circadian clock, and temperature responsiveness, and this genetic variation undoubtedly contributes to the ability of these species to thrive in diverse environments. It is important to extend the study of these complex genetic interactions to the environments experienced by crop plants, because the genetic mechanisms that underlie flowering time likely interact with the environment and determine the latitude over which a crop can be cultivated. The Brassica crops offer an especially attractive system. First, Brassica is closely related to Arabidopsis, which means that this model system offers a powerful information base to support such studies. Second, the Brassica species offer enormous diversity in morphology: B. rapa is cultivated for seeds, vegetables, and storage organs, and the cultivated types represent only a fraction of the diversity in the genus. This project will evaluate B. rapa natural variation in circadian clock function, flowering time, and flower size and shape in response to daylength and temperature. In addition, the contributions of this variation to the ability of B. rapa to thrive across a broad environmental range will be studied. Finally, this project will develop a mutagenized B. rapa population and laboratory exercises to use this population for the teaching of genetics for K-12 and undergraduate education.Broader Impacts: This project will shed new light on fundamental questions and has the potential to add value to Brassica crops (representing over $1 billion/yr in value) in terms of manipulation of flowering time and daylength responses. This project also offers educational opportunities at the undergraduate, predoctoral and postdoctoral levels in quantitative molecular and classical genetic analysis. In addition, this project will develop rapid-cycling B. rapa mutants as an educational resource to teach classical, molecular, and biochemical genetics at the K-12 and undergraduate levels. This will expand the Wisconsin 'FastPlants' program which is a resource that has already gained widespread acceptance in the classroom. Thus, the outreach aspects of this project should be manifest on a national level. Access to data generated in this project will be accessible through a project website. Germplasm generated will be available on request as well as through the Arabidopsis Biological Resource Center.