西藏毛壳菌属真菌多样性及抑菌活性的研究

Chaetomium spp. are important biocontrol fungi which are widely distributed in various cellulose-containing matrix with the function of breaking down cellulose, damaging the cell wall of pathogens, they are great development potential resources fungi. Currently, but very limited sampling places and samples were studied in Tibet. The project is planned to collect specimens from seven regions and cities in Tibet, through morphology, biological characteristics and molecular biology to clear population structure, dominant species and ecological distribution characteristics of Chaetomium in the different ecological zones. Using important plant pathogens to find out antagonistic strains, through the greenhouse efficiency experiments to determine the biocontrol effect of high-activity strains close to natural conditions, The systematic investigation and research projects on the resources and antibacterial activity of Chaetomium in Tibet will comprehensively understand Chaetomium resources, establish the Chaetomium repository in Tibet, lay the foundation for the protective development of Chaetomium resources and discover new active metabolite of Chaetomium, has important theoretical significance and application value.

毛壳菌是一类重要的生防真菌,广泛分布于自然界各种含纤维素的基质上，具有分解纤维素，破坏病原菌细胞壁的作用，是一类极具开发潜力的资源真菌。但目前，国内外学者对西藏毛壳菌的研究所涉及的采样地及样本数量很有限。本项目计划从西藏7个地市采集标本，通过形态学、生物学特性和分子生物学多层次的研究，对分离到的菌株进行鉴定，确定其分类地位，明确不同生态区中毛壳菌的种群结构、优势种群和生态分布特征。以农业生产中危害较为严重的植物病原菌为靶标菌，进行拮抗菌株的筛选，通过温室盆栽防效实验，确定高活性菌株在接近自然条件下的生防效果。本项目对西藏毛壳菌资源及其抑菌活性进行系统研究，将全面了解西藏毛壳菌资源状况,建立西藏毛壳菌资源库，为保护性开发西藏毛壳菌菌种资源和发掘新型毛壳菌活性代谢产物奠定基础，具有重要的理论意义和应用价值。

为了系统研究西藏毛壳菌资源现状和西藏不同生态区的毛壳菌种群结构、优势种群和分布规律，筛选适合于生物防治的高活性菌株。本课题从西藏七个地市采集土壤、植物残体、动物粪便标本965份，共分离到82株毛壳菌，平均分离几率为8.50%。不同地区的毛壳属真菌的优势种存在差异：拉萨的优势种为粪生毛壳C. funicola；山南地区优势种为黑毛壳C. nigricolor；那曲地区只分离到一种毛壳菌粪生毛壳C. funicola；林芝地区的优势种为球毛壳C. globosum和粪生毛壳C. funicola；昌都地区的优势种为粪生毛壳C. funicola。挑选代表性的75株毛壳菌分别进行28S rDNA、rDNA-ITS、β-tubulin和EF-1a基因序列扩增，结合形态学特征将86个菌株鉴定为13个种：分别为球毛壳C. globosum，粪生毛壳C. funicola，旋丝毛壳C. bostrychodes，反卷毛壳C. convolutum，印度毛壳C. indicum，近缘毛壳C. subaffine，黑毛壳C. nigricolor、大果毛壳C. megalocarpum、直立毛壳C. erectum、高大毛壳C. elatum、粗壮毛壳C. robustum、马德拉斯毛壳C.madrasense和蟹枝毛壳Chaetomium cancroideum。其中C. megalocarpum、C. elatum、C. robustum和C.madrasense都仅分离到1株，为少见种。.通过皿内菌菌拮抗实验、毛壳菌发酵粗提物抑菌实验、孢子萌发实验、离体/活体接种实验，筛选出具有较好抑菌效果的球毛壳菌22-10和黑色毛壳菌72-4-1。尤其是球毛壳菌22-10防效显著，该菌对小麦根腐病、小麦全蚀病、马铃薯干腐病、苹果褐腐病、苹果霉心病均有较好的控制效果，对其代谢产物开展研究，共得到6种化合物：Epichaetoviridin A，Chaetoviridin A，Chaetoviridin E，Chaetoglobosin C，Chaetoglobosin T，Prochaetoglobosins I。.本课题对西藏毛壳菌资源进行系统研究，可以丰富西藏真菌资源种类，为建立西藏毛壳菌菌种资源库提供了科学理论依据，也为生物防治和开发特殊生境下的微生物活性产物奠定基础。