DISSERTATION RESEARCH: Evolution and domestication genetics of the mango

芒果最早在4,000多年前在印度被驯化。今天，芒果种植在六大洲，是世界上最重要的热带水果之一。面对气候变化和人口增长，农业必须努力提高作物产量，同时面对新的和多变的气候条件。处理这些压力的特性，如耐旱性和抗病性，可以通过作物育种计划引入作物。虽然有数百种植物物种经历了驯化，但关于驯化对遗传多样性影响的许多概念都来自于对玉米和水稻等短命作物的研究。这种关注在我们对其他植物物种（如果树）的驯化知识中留下了空白。在驯化过程中，许多作物失去了遗传多样性，这可能导致对农业有用的有益性状的无意损失。然而，一些证据表明，长寿植物，如果树，可能不太容易受到驯化的负面影响。该项目将以最近的努力为基础，通过提供对芒果进化历史的基本了解，扩大对非主粮作物驯化的科学见解，并为未来的育种计划奠定基础，以提高其农业品质。芒果（Mangifera indica L.）（漆树科），分布于整个热带和温暖的亚热带。然而，芒果的东迁和向西迁可能对栽培芒果的遗传结构和多样性产生了显著不同的影响。在向西穿越非洲和美洲的过程中，芒果遭受了一系列的人口瓶颈，这表明该作物的遗传多样性有限地到达了新大陆。相反，向东扩张到东南亚使它与超过35个其他芒果属物种接触。形态学证据和初步的遗传数据表明，M.东南亚的籼稻可能是由这些野生亲缘植物的基因流支持的。本研究将利用双酶切限制性位点相关DNA（ddRAD）测序技术对世界各地植物园栽培的192份芒果种质（包括116份芒果种质）的遗传多样性、种群分化和杂交进行研究。已知地理起源的籼稻品种和76个来自其他四个区域栽培芒果属物种的加入。

The mango was first domesticated in India more than 4,000 years ago. Today, mangoes are grown on six continents and are one of the world's most important tropical fruits. In the face of climate change and a growing human population, agriculture must strive to improve crop yields while facing new and variable climatic conditions. Traits to deal with these stressors, like drought tolerance and disease resistance, can be introduced into crops through crop breeding programs. Although hundreds of plant species have undergone domestication, many concepts about the impacts of domestication on genetic diversity have come from research focusing on short-lived crops like maize and rice. This focus has left gaps in our knowledge about domestication in other plant species, such as fruit trees. During the process of domestication, many crops lose genetic diversity, which can result in the unintentional loss of beneficial traits that could be useful for agriculture. However, some evidence that suggests long-lived plants, like fruit trees, may be less susceptible to the negative impacts of domestication. This project will build on recent efforts to expand scientific insight into the domestication of non-staple crops by providing a basic understanding of the evolutionary history of the mango, and will lay the groundwork for future breeding programs to improve its agricultural qualities. Following its original domestication, the mango, Mangifera indica L. (Anacardiaceae), was dispersed throughout the tropics and warm subtropics. However, the eastward and westward migrations of Mangifera indica may have had strikingly different effects on the genetic structure and diversity of cultivated mango. During its journey westward through Africa and on to the Americas, Mangifera indica suffered a series of population bottlenecks, suggesting that a limited amount of the crop's genetic diversity reached the New World. Conversely, eastward expansion into Southeast Asia brought it into contact with more than 35 other Mangifera species. Morphological evidence and preliminary genetic data indicate that the genetic diversity of M. indica in SE Asia may have been bolstered by gene flow from these wild relatives. This research will use double digest restriction site associated DNA (ddRAD) sequencing to investigate genetic diversity, population differentiation, and hybridization in 192 Mangifera accessions cultivated at Botanic Gardens around the world, including 116 M. indica cultivars of known geographic origin and 76 accessions from four other regionally-cultivated Mangifera species.