钩丝孢属真菌资源和系统学研究

Harposporium, an important group of endoparasitic nematophagous fungi, is of great value in investigating biodiversity. However, only four species of Harposporium have been reported in China, there may be many undescribed species in China. And their conidia are morphologically diverse and changeable, which makes it difficult for us to accurately identify Harposporium with traditional classifying methods. With the implementation of one fungus one name, it is urgent to solve the problem of classification and naming. Based on the Harposporium resources available, our project will 1) carry out systematic investigation of Harposporium resources in different media such as forest soil, farmland soil, animal dung, decayed woods and decayed foliage in different areas in China, 2) build the taxonomic position of Harposporium in accordance with the morphological features of Harposporium, multi-gene analysis and the related data in GenBank through studying samples and strains obtained abroad and at home, and 3) analyze the biodiversity of these fungi and their community differences with species richness index and community similarity index. Our research results will enrich nematophagous resources and lay a solid foundation for building a complete type of one fungus one name classification system as well as for the bio-utilization of Harposporium.

钩丝孢属（Harposporium Lohde）真菌是线虫内寄生真菌的重要类群，也是研究生物多样性不可多得的材料。但在国内仅报道了4种，其物种资源有待发掘。该属真菌分生孢子的形态多样性和易变性，使其部分种类的分类地位很难确定，且随着一种真菌一个名称的实施，这类真菌的系统分类及命名问题也急需解决。本项目拟在现有钩丝孢属菌种资源的基础上，从不同地区的森林土、农田土、动物粪便、腐木和腐叶样本中，系统调查我国钩丝孢属真菌资源，并广泛索取国内外该类群标本和菌种，通过形态学、多基因系统发育分析以及GenBank相关数据，建立该类群的系统分类地位，同时采用物种丰富度指数、群落相似性指数分析这类真菌的物种多样性和群落差异。项目研究结果将会丰富我国食线虫真菌资源，也为今后一种真菌一个名称的全型性分类系统和钩丝孢属真菌的生物利用奠定基础。

钩丝孢属真菌是食线虫真菌中的一类线虫内寄生真菌。本项目调查钩丝孢属真菌资源和研究其分子系统学。按预设采样点共采集样本2450份，获得钩丝孢属真菌28株，并利用ITS、stSSU和28S大亚基基因对23株钩丝孢属真菌进行分子系统学分析。取得以下主要研究结果：分离鉴定出H. anguillulae、H. lilliputanum、H. oxycoracum、H. helicoides、H. thaumasium 5种已知真菌（16株）和12种待定疑难种，并从中获得1株高产胞外蛋白酶的具有线虫生防潜力的菌株；分子系统学研究获得该属真菌分子序列69条，初步表明钩丝孢属真菌分生孢子的螺旋型和弓形，及其大小为分类的主要特征，节孢子和附孢子也是分类的一个主要依据。研究结果极大的丰富了该属菌种资源库，为该属真菌的系统学研究提供了有价值的基础数据。