Systematics of the Genus Cordyceps (Ascomycota, Hypocreales) and the Evolution of Host-shifts

9806936子囊菌科(子囊菌门：下胚菌目)是真菌的一个多样化的单系家族，其不同寻常之处在于它完全由其他生物的专性共生体组成：草、节肢动物或其他真菌。这些物种中有许多具有重要的经济价值；例如，它们包括导致绵羊“摇摇晃晃”的草内生真菌。冬虫夏草是鸡冠花科植物中种类最多、形态最丰富、寄主范围最广的一种。冬虫夏草和冬虫夏科的寄主范围与严格的同种(“寄主追踪”)假设不一致；如果是这样，那么一旦一个物种与特定的寄主相关联，那么它的所有后代都将与该寄主及其后代相关联。目前冬虫夏草和冬虫夏科的寄主范围是通过一系列复杂的界内和界内寄主转移而形成的。为了验证这一假说，需要对这些真菌的历史(系统发育)进行强有力的重建。目前没有可用的。在这项研究中，Joseph Spatafora和Richard Humber将对冬虫夏草属和近缘棒状真菌进行系统调查。他们将利用DNA序列数据和形态研究的特征重建真菌的系统发育。然后，他们将利用系统发育来开发虫草属下基于系统发育的分类，将无性真菌(无性系)整合到虫草属的分类中，并描述该属内寄主转移的历史。这项工作应该为正在进行的和未来关于这种具有智力刺激和经济重要性的真菌群体的生物学方面的工作奠定坚实的基础。

9806936 SPATAFORA The Clavicipitaceae (Ascomycota: Hypocreales) is a diverse, monophyletic family of fungi that is unusual in being composed entirely of obligate symbionts of other organisms: grasses, arthropods, or other fungi. A number of these species are of economic importance; they include, for example, the grass endophyte responsible for "staggers" in sheep. Cordyceps is the most diverse genus of the Clavicipitaceae, both in terms of number of species and in its morphology and remarkably wide range of hosts. The host range exhibited by Cordyceps and the Clavicipitaceae is inconsistent with a hypothesis of strict cospeciation ("host tracking"); if it were, then once a species became associated with a particular host, then all of its descendants would be associated with that host and its descendants. It is proposed that the current host range of Cordyceps and the Clavicipitaceae arose via a complex series of inter- and intrakingdom host-shifts. A robust reconstruction of the history (phylogeny) of these fungi is needed to test this hypothesis. None is currently available. In this research, Joseph Spatafora and Richard Humber will conduct a systematic investigation of the genus Cordyceps and allied clavicipitacean fungi. They will reconstruct the phylogeny of the fungi using characters from DNA sequence data and morphological studies. They will then use the phylogeny to develop a phylogenetically-based infrageneric classification of Cordyceps, integrate asexual fungi (anamorphs) into the classification of Cordyceps, and describe the history of host-shifts within the genus. The work should form a firm basis for ongoing and future work on the biology of this intellectually stimulating and economically important group of fungi.