Improving food security in Africa: taxonomy, genetics and ecology of finger-grasses

现代非洲农业不稳定地依赖于欧洲定居者引进的农作物。这些外来的和遗传上一致的食物和饲料植物容易感染疾病，需要的水比通常可用的更多。他们无法支持非洲大陆不断增长的人口。然而，农业已经忘记了原产于非洲的植物：对食品和牧草生产行业来说并不熟悉，但在干旱情况下进化而来，具有当地多样性，由于缺乏基本的植物学基础，具有很大程度上尚未开发的潜力。指状草(禾本科)是一个重大的全球知识鸿沟，由277种草本植物组成，具有表面相似的指状花序和微小的开花部分，如果没有强大的显微镜，就看不到区别。实地调查通常忽略了它们；自1950年以来就没有尝试过分类处理；它们的进化关系尚不清楚。已经记录了多个水平的多倍体，核基因历史是复杂的，指草甚至可能不是一个单一的进化谱系。然而，在整个非洲，洋地黄出产丰富多汁的叶子，所有的牛都喜欢吃，而穿山甲草(洋地黄)是作为牧草种植的。非洲马唐包括神秘的马唐：世界上唯一已知的作物，由两个遗传不同的物种混合而成：马唐和马唐。这个项目将调查非洲马唐的进化史和环境生态位，以提出最理想的未来饲料和食物开发，以应对与人口增加、干旱和气候变化有关的土地利用变化。将对所有已知用于商业用途的非洲马唐物种进行遗传和实验研究，以确定它们的分布、丰度、物候和产量。将对Kew的标本进行研究，以通过形态分类学确定物种边界。将通过NGS序列数据进行系统发育重建，以确定最有潜力喂养动物和人类的物种。生态位模型将探索在不同气候变化情景下可能有用的领域。学生将在皇家植物园Kew、马里乡村经济研究所和帝国理工学院生态与进化国际卓越中心(https://www.imperial.ac.uk/visit/campuses/silwood-park)，进行接待，该中心的生态系统和环境倡议(http://www.imperial.ac.uk/ecosystems-and-environment).重大挑战

Modern African agriculture is precariously reliant on crops introduced by European settlers. These foreign and genetically uniform food and forage plants are susceptible to disease and require more water than is frequently available. They are failing to support the continent's growing population. Yet the agricultural industry has forgotten plants native to Africa: unfamiliar to food and pasture production industries yet evolved under drought, locally diverse, and with potential which is largely untapped due to the lack of a basic botanical knowledge base.The finger-grasses (Poaceae genus Digitaria) are a significant global knowledge gap, a group of 277 grasses with superficially similar finger-like inflorescences and tiny flowering parts, with differences important for identification not visible without a powerful microscope. They are commonly missed by field surveys; there has been no attempt at a taxonomic treatment since 1950; and their evolutionary relationships are unknown. Multiple levels of polyploidy have been recorded, nuclear gene histories are complex, and finger-grasses may not even be a single evolutionary lineage. Yet across Africa Digitaria produces abundant juicy leaves loved by all cattle and Pangola grass (Digitaria eriantha) is cultivated for pasture. African Digitaria includes the mysterious fonio: world's only known crop which is a mixture of two genetically different species: Digitaria exilis and Digitaria iburua. Other species have become vigorous weeds of global importance.This project will investigate the evolutionary history and environmental niches of Digitaria in Africa in order to propose the most optimal future forage and food exploitation for resilience against land use change associated with population increase, drought and climate change. All species of African Digitaria already known for commercial uses will be investigated genetically and experimentally to establish their distribution, abundance, phenology, and yields. Herbarium specimens at Kew will be studied to determine species boundaries through morphological taxonomy. Phylogenetic reconstructions will be made through NGS sequence data in order to identify species with best potential for feeding animals and people. Niche modelling will explore areas Digitaria can be useful under different climate change scenarios.The student will be hosted at Royal Botanic Gardens Kew, Institut d'Economie Rurale in Mali, and Imperial College's international centre of excellence in ecology and evolution (https://www.imperial.ac.uk/visit/campuses/silwood-park), under its Grand Challenges in Ecosystems and the Environment Initiative (http://www.imperial.ac.uk/ecosystems-and-environment).