Phylogeny and Taxonomy of Ostropalean Fungi, with Emphasis on the Lichen-forming Thelotremataceae

Ostropalean 真菌的系统发育和分类学，重点是地衣形成的 Thelotremataceae

• 批准号: 0516116
• 负责人: Thorsten Lumbsch
• 金额: $ 28.13万
• 依托单位: Field Museum of Natural History
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0516116&HistoricalAwards=false
• 关键词: Phylogeny; Taxonomy; Ostropalean; Fungi; Emphasis

Until one and a half centuries ago, the colorful lichens that colonize soil, rocks and trees from the tundra to the hot and dry deserts were believed to be organisms separate from plants and fungi. Their similarity with certain fungi and algae was partly explained by the idea that lichens occupy a taxonomic position intermediate between those two groups. With the discovery (in 1867) that lichens are in fact a symbiosis between fungi and algae, and more particularly involve a mode of nutrition by specialized fungi, the lichen-forming fungi came gradually to be integrated into the fungal system of classification. The first large-scale molecular, DNA-based phylogeny of lichen-forming fungi (1995) seemed to confirm that lichenization evolved many times independently within the fungi, but a recent study (2001) has proposed an alternative, that there was only one major lichenization event within Ascomycota, from which secondarily non-lichenized fungi evolved along several lineages, including such important groups as Aspergillus and Penicillium. Additional studies on the molecular phylogeny of Ascomycota suggest that the situation is more complex, with one or two major lichenization events, several delichenization events, and possibly even relichenization events. One of the biologically and morphologically most diverse fungal groups are the Ostropales, which include lichenized and lichenicolous (fungi parasitizing lichens) groups, as well as non-lichenized saprotrophs and plant parasites. Ostropales are derived from a lichenized ancestor, which means that their non-lichenized lineages are delichenized and some lichen-forming fungi within these groups could be secondarily relichenized. To test this hypothesis, and in close collaboration with the Fungal Tree of Life project, the investigators will reconstruct the phylogeny of Ostropales, emphasizing acquisition of DNA sequence data from nuclear and mitochondrial genes along with morphological and lichen-chemistry studies, much of these for specimens to be collected on field trips in Asia and South America. Among the groups under study, the Thelotremataceae is by far the largest family, with about 600 species, and 300 are targeted for collection. Its members form an important component of tropical ecosystems. A revised genus-level classification for the group will improve classification and facilitate studies in biogeography and ecology. Training and outreach are important aspects of the project, which will include support for graduate student thesis work, joint field trips with foreign colleagues and their students, development of specimen databases for holdings at the Field Museum, and an international workshop on systematics and identification keys for Ostropales and Thelotremataceae.

直到一个半世纪前，从冻土带到炎热干燥的沙漠，在土壤、岩石和树木上定居的五颜六色的地衣被认为是与植物和真菌分开的有机体。它们与某些真菌和藻类的相似性部分是因为地衣在分类上占据了介于这两个类群之间的位置。随着1867年发现地衣实际上是真菌和藻类的共生，更具体地说是涉及到特殊真菌的营养方式，形成地衣的真菌逐渐被整合到真菌分类系统中。第一个大规模的基于DNA的地衣形成真菌分子系统发育(1995)似乎证实了地衣形成在真菌中独立进化了多次，但最近的一项研究(2001)提出了另一种选择，即子囊菌中只有一个主要的地衣形成事件，次要的非地衣形成的真菌沿着几个谱系进化，包括曲霉和青霉等重要类群。对子囊菌分子系统发育的进一步研究表明，情况更为复杂，有一到两个主要的地衣事件，几个细菌化事件，甚至可能有再石灰化事件。生物和形态上最多样化的真菌群之一是介形类，它包括地衣和地衣(寄生地衣的真菌)群，以及非地衣腐殖体和植物寄生虫。介形类起源于地衣化的祖先，这意味着它们未地衣化的谱系是精化的，这些类群中的一些形成地衣的真菌可以二次重新地衣化。为了验证这一假说，并与真菌生命树项目密切合作，研究人员将重建介形类的系统发育，重点是从核和线粒体基因获取DNA序列数据，以及形态和地衣化学研究，其中大部分是用于在亚洲和南美洲实地考察时收集的标本。在所研究的类群中，吸虫科是迄今为止最大的科，约有600种，其中300种是收集的目标。其成员构成了热带生态系统的重要组成部分。修订后的属级分类将改进分类，并促进生物地理学和生态学的研究。培训和外联是该项目的重要方面，其中将包括支持研究生论文工作，与外国同事及其学生联合进行实地考察，开发外地博物馆馆藏标本数据库，以及举办关于介形藻类和海龙属植物分类学和识别检索表的国际讲习班。