Exploring the genetic basis of transgressive variation in rice.

合作伙伴：Carlos D. Bustamante（康奈尔大学），Georgia C. Eizenga（阿肯色大学/美国农业大学），Anna M. McClung（德克萨斯农机大学）水稻（Oryza sativa）是一个复杂的物种，由至少五个遗传上可区分的亚种群组成，分布在亚洲不同的生态和地理区域。迄今为止的证据表明，这些群体表明了一般配合力，类似于玉米的杂种优势群体。该项目旨在检验水稻亚种群结构预测越界变异的假设，并开始描述这一现象的潜在遗传基础。为此，研究人员将1)使用高分辨率SNP测定方法记录水稻不同亚群内部和之间等位基因变异的全基因组差异；2)使用26个核心农艺性状和籽粒品质性状的表型评估对水稻进行关联定位；3)系统地开发遗传材料，使我们能够探索亚种群杂交时多样性与越界变异之间的关系；4)建立水稻数据集，可以与玉米多样性项目的数据集进行比较，并最终与其他谷物物种进行比较。作为有针对性的教育推广工作的一部分，调查人员将在当地高中开展动手基因组学练习，邀请高中生和本科生作为暑期实习生，重点是扩大代表性不足群体的参与，并将制作多媒体视频演示文稿，探索美国和非洲的水稻文化，与k -8年级的学生分享。更好地了解近交系作物物种越界变异的遗传基础将对全球作物改良研究议程产生直接影响。目前，杂交水稻作为一种向农民提供优质品种的机制，引起了人们的极大兴趣。但是，如果没有对自然近交系物种优越性能的遗传机制的科学理解，世界上近交系作物品种中一些最有希望获得优越性能的机会可能会被忽视。从该项目中获得的知识将有助于思考如何最好地表征和管理稻谷基因库，以及我们作为一个社会，在开发我们最重要的主食的自交系和/或杂交品种时选择的相关投资。作为该项目的一部分所生产的遗传资源将通过位于阿肯色州斯图加特的Dale Bumpers国家水稻研究中心（DBNRRC）和位于科罗拉多州柯林斯堡的国家遗传资源保护中心（NCGRP）设施的遗传资源-水稻（GSOR）增加可获得的收集。有关水稻多样性的信息将通过该项目的网站、GRIN数据库提供，并将被整合到Gramene数据库（www.gramene.org）中。

PI: Susan r. McCouch (Cornell University-State)CO-PIs: Carlos D. Bustamante (Cornell University), Georgia C. Eizenga (University of Arkansas/ARS), Anna M. McClung (Texas A&M University) Rice (Oryza sativa) is a complex species consisting of at least five, genetically distinguishable sub-populations that inhabit diverse ecological and geographic zones throughout Asia. Evidence to date suggests that these groups are indicative of general combining ability, similar to the heterotic groups of maize. This project is designed to test the hypothesis that sub-population structure in rice is predictive of transgressive variation and to begin to characterize the underlying genetic basis of this phenomenon. To do this, the Investigators will 1) document the genome-wide differences in allelic variation within and between the different subpopulations of O. sativa and O. rufipogon using a high resolution SNP assay, 2) undertake association mapping in rice using phenotypic evaluations for 26 core agronomic and grain quality traits, 3) systematically develop genetic materials that will allow us to explore the relationship between diversity and transgressive variation that occurs when subpopulations are crossed and 4) establish a dataset for rice that can be compared with that of the maize diversity project and ultimately with other cereal species. As part of a targeted educational outreach effort, the Investigators will conduct hands-on genomics exercises in local high schools, host high school and undergraduate students as summer interns with an emphasis on broadening participation of underrepresented groups, and will develop a multi-media video presentation exploring the culture of rice in America and in Africa to be shared with K-8th graders.A better understanding of the genetic basis of transgressive variation in inbred crop species will have an immediate impact on the global research agenda for crop improvement. Presently, there is a great deal of interest in breeding hybrid rice as a mechanism for delivering superior varieties to farmers. But without a sound scientific understanding of the genetic mechanisms that underlie superior performance in naturally inbreeding species, some of the most promising opportunities to capture superior performance in the world's inbred crop varieties may be overlooked. The knowledge to be gained from this project will help inform thinking about how to best characterize and manage Oryza gene pools and about the relative investments that we, as a society, choose to make in developing inbred and/or hybrid varieties of our most important food staples. The genetic stocks produced as part of the project will augment the collection available through the Genetic Stocks-Oryza (GSOR) located at the Dale Bumpers National Rice Research Center (DBNRRC) in Stuttgart, Arkansas and the National Center for Genetic Resources Preservation (NCGRP) facility in Fort Collins, CO. Information on rice diversity will be available over the project web-site, the GRIN database and will be integrated into the Gramene database (www.gramene.org).