毛壳科真菌无性型的系统分类学研究

The Chaetomiaceae are a huge promsing resource of hydrolytic enzymes and bioactive metabolites, and also contain some important human pathogens. The current classification system mainly focuses on the teleomorph members of the Chaetomiaceae. However, at least ten anamorphic "genera" have been indicated to include species of the family, which are Acrophialophora、Botryotrichum、Humicola、Madurella、Myceliophthora、Papulaspora、Retroconis、Staphylotrichum、Taifanglania and Trichocladium. These anamorphic genera are established mainly based on morphology with little phylogenetic data to support them. There has been evidence that Humicola and Trichocladium are polyphyletic. After the study of the sexual isolates of Chaetomiaceae deposited in the collection of CBS-KNAW (the Netherlands) which represent a worldwide resource of this group of fungi, the applicant has constructed an overall framework of multigene phylogeny of the teleomorphic Chaetomiaceae. At the same time the anamorphic genus Botryotrichum now has proved to involve not only anamorphic but also typical teleomorphic species. In this envisaged study, based on multigene analyses and comparative genome study, we will select suitable molecular markers to both anamorph and teleomorph for their phylogenetic analysis, and then each of the anamorphic species will be phylogenetically placed in the family and their closely-related teleomorphic relatives will be recognized. All the anamorph-related genera will be re-evaluated or redefined on the basis of morphology, growth temperature and multigene phylogeny with the teleomorph members of the family as references. Eventually, a complete and natural classification system of the Chaetomiaceae will be established. The results will contribute to understanding how the species in the family are differentiated and how they adapt to different eco-environments. This study will help making informed choices for the exploitation and utilization of Chaetomiaceae in industry and medicine and also help identifying the harmful species to the human.

毛壳科真菌是应用潜力巨大的纤维素酶和生物活性物资源库，但也含重要的人体致病菌。现有的分类系统主要关注其有性型种。有证据显示，至少10个无性型“属”内有毛壳科的成员。这些“属”大多基于形态，缺乏系统学研究，并已知其中的Humicola、Trichocladium等是异源“属”。申请者在前期已搭建了毛壳科有性型的多基因谱系框架，同时证明原无性型属Botryotrichum内还包含有性型种。本项目拟在前期研究的基础上，在科的整体框架下通过多基因序列分析和比较基因组学研究，选定同时适宜于无性型和有性型的分子标记；明确相关无性型“属”在科内的系统发育位置及其与有性型间的关系；结合形态、温度适应性等研究科学定义各相关属和属内各种。研究结果将建立一个完整而趋于自然的毛壳科现代分类系统，为进一步揭示这类真菌的物种分化和生态适应性规律奠定科学基础，同时为理性发掘和利用有益资源及科学鉴别有害种提供科学指导。

毛壳科真菌隶属于真菌界子囊菌门，粪壳纲下的粪壳目，是一个具有巨大开发应用潜力的生物资源库：科内物种可分泌纤维素酶等多种胞外酶和丰富的生物活性次生代谢产物，且真菌界内已知的嗜热种多半属于毛壳科。此前国际上对毛壳科的专著性研究仅仅关注有性型种，而且主要依据形态学分类系统，未能反映各个属、种的自然进化特征和彼此间的系统演化关系。我们在本基金面上项目的资助下，以采自我国和保藏于CBS国际菌种保藏中心的来自全球不同国家和地区的毛壳科菌株为研究材料，通过多基因系统发育分析和全面的形态学研究取得了以下成果：1）澄清了科内无性型物种和有性型物种间的系统发育关系，证明过去被定义为无性型属的Acrophialophora、Botryotrichum、Humicola、Staphylotrichum、Trichocladium都非单系群，其中包含有性型种，首次明确Canariomyces属于毛壳科的成员，在此基础上，重新修订了科内10个已知属的概念和边界。2）建成一个完整、稳定而趋于自然的毛壳科现代分类系统，其中包括：建立了1个新科，13个新属；描述了 20 个新种和 63 个新组合；同时为6个早期发表种重新指定了新模式、选模式或表征模式，稳定了它们的分类地位。3）通过103 个彩色图版，重新呈现了所研究物种的形态学特征，同时展示了一些种内的形态多样性。研究结果以2篇本项目为第一标注的专著性学术论文，发表在真菌学领域的顶级期刊Studies in Mycology上。研究结果彻底更新了毛壳科真菌的分类系统，明确了科内属、种间的系统演化关系，推动了毛壳科真现代分类学的进步，为进一步开发应用科内具有潜力的生物资源提供了科学依据和理论指导。