RESEARCH-PGR: The Genetics of Highland Adaptation in Maize

玉米起源于大约10,000年前墨西哥西南部一个炎热、干燥、低海拔的地区。虽然玉米已经在全球范围内传播，并且今天拥有16种主要作物中最大的全球地理范围，但玉米在寒冷中仍然表现不佳。然而，不同地区的农民确实在海拔12，000英尺的凉爽潮湿山区种植玉米。该项目将确定允许玉米适应高海拔的遗传变化。研究人员将在高、中、低地进行田间试验，比较高海拔地区和附近低地地区玉米品种的农艺性状和遗传性状。这些实验将揭示高海拔适应的基因基础，并将测量适应的遗传变化的可重复性。这项研究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。深入了解高原条件下的适应过程也可以更广泛地应用于玉米对其他环境条件的适应。该项目将促进学术界和工业界之间的合作，美国和墨西哥之间，创造了大量的机会，学生，调查人员和农民从这些国家互动和分享expertinence.Part 2：技术abstractThe遗传基础的植物适应当地环境仍然不佳的特点，尽管它的相关性作物改良和区域气候。该项目旨在评估玉米（Zea mays）的环境适应性，重点是野生和驯化玉米种群对高海拔环境的适应性。高地和低地环境在许多特征上不同，包括温度和降水，玉米对这些环境的适应涉及农艺学相关的表型。第一个目标是使用从墨西哥和南美玉米开发的作图群体来鉴定适应性性状的数量性状基因座，所述墨西哥和南美玉米是大刍草的天然混合群体（即，野生玉米）和由工业合作者捐赠的两个渐渗系群体。这将使控制高原性状的基因座在不同的地理区域，海拔，并在多个遗传背景，包括美国玉米种质的比较。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和高地玉米之间基因表达的差异来调查选择的群体遗传证据。第三个目标是通过对渐渗系的表型和转录组学评价来表征适应性倒位多态性的功能后果。这项基础研究将辅之以外展活动，包括表型分析研讨会，以展示高通量的田间数据收集方法，学生交流，以及与墨西哥育种中心合作的农民田间展览。

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.