RESEARCH-PGR: The Genetics of Highland Adaptation in Maize

研究-PGR：玉米适应高原的遗传学

• 批准号: 1546719
• 负责人: Jeffrey Ross-Ibarra
• 金额: $ 407.86万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-15 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1546719&HistoricalAwards=false
• 关键词: RESEARCH; PGR; Genetics; Highland; Adaptation

Part 1: Non-Technical abstract Corn originated approximately 10,000 years ago in a hot, dry, low-elevation region of southwest Mexico. While it has since spread globally and today has the greatest global geographic breadth of 16 staple crops, corn continues to perform poorly in the cold. However, farmers in various regions do cultivate corn in cool, wet mountainous regions as high as 12,000 ft above sea level. This project will identify the genetic changes that allowed corn to adapt to high elevations. The investigators will compare agronomic and genetic traits of corn varieties sampled at high elevation with those from nearby lowland regions in field experiments conducted at high, middle, and lowland sites. These experiments will reveal the genes underlying high-elevation adaptation and will measure the repeatability of the genetic changes underlying adaptation. Results from this investigation will inform the development of cold-hardy corn lines for high-elevation and high-latitude (e.g. U.S. Corn Belt) regions. Insight as to how adaptation occurred in highland conditions can also be applied more broadly to adapting maize to other environmental conditions. This project will foster collaboration between academics and industry and between the United States and Mexico, creating numerous opportunities for students, investigators, and farmers from these countries to interact and share expertise.Part 2: Technical abstractThe genetic basis of plant adaptation to local environments remains poorly characterized, despite its relevance to crop improvement and regional climate. This project seeks to evaluate environmental adaptation in maize (Zea mays), with focus on adaptation to high elevation environments in wild and domesticated populations of maize. Highland and lowland environments differ in a number of features including temperature and precipitation, and maize adaptation to these environments has involved agronomically relevant phenotypes. The first objective is to identify quantitative trait loci for adaptive traits using mapping populations developed from Mexican and South American maize, a naturally admixed population of teosinte (i.e., wild maize) and two populations of introgression lines donated by industry collaborators. This will enable the comparison of the loci controlling highland traits in distinct geographical regions, across elevations, and in multiple genetic backgrounds including elite US maize germplasm. The second objective is to investigate population genetic evidence of selection through studies of adaptive introgression in maize and teosinte, and divergence in gene expression between lowland and highland maize. The third objective is to characterize the functional consequences of an adaptive inversion polymorphism via phenotypic and transcriptomic evaluation of introgression lines. This basic research will be complemented by outreach activities including phenotyping workshops to demonstrate high-throughput field data collection methods, student exchanges, and farmer field exhibitions in conjunction with a breeding center in Mexico.

玉米大约起源于一万年前墨西哥西南部一个炎热、干燥、低海拔的地区。虽然它已经传播到全球，并且今天在16种主要作物中拥有全球最大的地理宽度，但玉米在寒冷中仍然表现不佳。然而，许多地区的农民确实在海拔12000英尺的凉爽潮湿的山区种植玉米。这个项目将确定使玉米适应高海拔的基因变化。研究人员将在高、中、低地地区进行田间试验，比较在高海拔地区和附近低地地区取样的玉米品种的农艺和遗传性状。这些实验将揭示高海拔适应的基因，并将测量适应的遗传变化的可重复性。这项调查的结果将为高海拔和高纬度地区（如美国玉米带）耐寒玉米品系的开发提供信息。关于高原条件下如何发生适应的见解也可以更广泛地应用于使玉米适应其他环境条件。该项目将促进学术界和工业界以及美国和墨西哥之间的合作，为来自这些国家的学生、研究人员和农民创造大量互动和分享专业知识的机会。尽管植物适应当地环境的遗传基础与作物改良和区域气候相关，但其特征仍然很差。本项目旨在评估玉米（Zea mays）的环境适应性，重点研究野生和驯化玉米种群对高海拔环境的适应性。高原和低地环境在包括温度和降水在内的许多特征上存在差异，玉米对这些环境的适应涉及农学上相关的表型。第一个目标是利用从墨西哥和南美玉米、大刍动物（即野生玉米）的自然杂交群体和两个行业合作伙伴捐赠的渐渗系群体开发的群体来确定适应性性状的数量性状位点。这将使控制高原性状的位点能够在不同地理区域、不同海拔和多种遗传背景下进行比较，包括在美国玉米优质种质中。第二个目标是通过研究玉米和大刍草的适应性渐渗以及低地玉米和高地玉米的基因表达差异来研究选择的群体遗传证据。第三个目标是通过对渗入系的表型和转录组学评估来描述适应性反转多态性的功能后果。这项基础研究将辅以外联活动，包括表现型讲习班，以展示高通量现场数据收集方法，学生交流，以及与墨西哥育种中心合作的农民现场展览。