芒属（禾本科）及其近缘类群的分类学研究

As the most productive perennial C4 grass in temperate climates, Miscanthus has emerged as a strong candidate for second-generation energy crops. Nowadays, the genus Miscanthus contains about 13-24 speceis distributed mainly in Asia. China is an important country to the genus in that China possesses the 7-20 native species and the richest natural resource of Miscanthus for the development of new energy crops. Owing to the insufficience of the taxonomic and systematic datasets in Miscanthus, the generic devision of Miscanthus is controversial and the phylogentic relationship among Miscanthus and its allies remains unclear, as well as the taxonomic treatments of some species are incongruous, limiting the development of the Miscanthus such as the artificial selection, breeding, and genetic engineering of the crops. In this project, we aim to clarify these problems in the light of the evidences from gross-morphology, anatomy, ecology, phytogeography, cytology and molecular phylogeny of Miscanthus. In order to make the credible taxonomic treatments, abundance of the specimen observation, extensive field investigation of population and elaborated laboratory research will be carried out. For understanding the morphological variation pattern, 41 numerical characters and 15 qualitative characters, including those from inflorescence, spikelet, sterile spikelet, fertile spikelet and caryopsis, will be observed and measured, and relationship between the morphologic characters and the environmental factors will be investigated. The characters that show significant difference between populations or taxa will be adopted to delimit the species and genera. The phylogenetic tree constructed based on 13 cpDNA and 3 nr DNA segments will be used to resolve the generic circumscription of Miscanthus and to infer evolutionary relationships of the species in the genus. The further phylogenetic analysis will be conducted to elaborate the biogeographical history and the evolution of morphological characters within the genus. In a word, this work is going to solve the taxonomic and systemtic problems of Miscanthus and to provide a step stone for domestication and improvement of Miscanthus crop.

芒属植物（泛称芒草）作为新一代潜在的能源作物正受到广泛关注，我国具有世界上最丰富的芒草自然资源。前期研究发现，芒属与近缘属属间界限不清晰，属内系统发育关系不明朗，部分种的分类处理混乱，类群演化历史、性状进化趋势等科学问题缺乏探讨，现有研究不能为芒属植物的驯化、引种、遗传改良和良种繁育工作提供清晰的研究背景和基础。本项目拟在前期芒属植物资源调查的基础上，综合应用形态学、细胞学和分子系统学等方面的证据，以居群为研究对象，对芒属及其近缘类群进行分类学研究。通过标本研究、野外居群调查以及微形态学研究，统计分析形态性状的变异式样，及与生态和地理分布的相关性，选择可靠的分类性状进行分类学处理，确认芒属植物的种类。利用分子系统树，辅以细胞学和形态学证据，探讨芒属和近缘属的界定及系统发育关系，完成该属植物的分类学研究。该研究将为芒属植物进一步的深入研究奠定基础，并为芒草资源开发利用提供清晰的研究背景。

本项目综合应用形态学、细胞学和分子系统学等方面的证据，以居群为研究对象，对中国芒属植物进行了深入的分类学研究。通过大量的标本观察、野外居群调查，统计分析形态性状的变异式样，及与生态和地理分布的相关性，选择可靠的分类性状对芒属植物进行了分类学处理，提出了狭义芒属的概念，确定世界芒属（狭义）包括8种1亚种。利用分子系统树，辅以细胞学和形态学证据，厘清了芒属和近缘属的界定以及系统发育关系，认为狭义芒属及其近缘类群形成三大支系，阐明了各大支系间的系统发育关系，并提出相应的分类处理意见；探讨了狭义芒属的迁移和演化历史，推测芒属及其近缘类群于上新世晚期起源于东亚地区，沿2条独立路径进行扩散。本项目研究成果为芒属植物的驯化、引种、遗传改良和良种繁育工作提供清晰的研究背景和基础，也为该类群进一步的深入研究奠定了基础。