藏东川西横断山地区黑粉菌锈菌物种多样性及区系特征

Smut fungi and rust fungi are parasites mainly of flowering plants, causing serious damage of cereal crops and industrial plants. Some species of smut fungi are utilized for edible vegetables and medicinal materials. They are significant components of most natural ecosystems. Hengduan Mountains in eastern Xizang and western Sichuan are widely regarded with rich fungal resources, but the smut and rust fungi are scarcely known. Even though molecular data is now widely used in fungal systematics and phylogeny, the valid description of a species still requires morphological characterization according to the International Code of Nomenclature for algae, fungi, and plants. These morphological descriptions, together with further observations on the described species, represent a valuable and comprehensive source of information, which is still extensively used today. Nevertheless, relying solely on morphological characters in the identification process can be problematic. The present project intends to use morphological characters and phylogenetic analyses based on ITS, 18S, 28S rDNA, β-tubulin gene and EF-1α gene partial sequence date, to study similar and difficult species of some genera of smut and rust fungi. ITS, 28S rDNA, β-tubulin gene and EF-1α gene will be selected as the candidate DNA barcode markers to investigate their feasibility of rapid and reliable species identification of some species of smut and rust fungi found in eastern Xizang and western Sichuan. The researches are being based on phenotypic-genotypic combination, including species inventory of biodiversity of smut and rust fungi in eastern Xizang and western Sichuan based on field investigation, establishing a regional species database of these groups of fungi affiliated to database of Herbarium Mycologicum Academiae Sinicae (HMAS), and the biogeographical studies or floristic analysis of rust and smut fungi in eastern Xizang and western Sichuan. The research is significant for conservation, exploitation and utilization of resources of smut and rust fungi and for control of harmful fungi.

藏东川西横断山地区菌物资源丰富，但黑粉菌锈菌已知种数仍显太少，通过野外科学考察，开展黑粉菌锈菌区系调查研究。在形态学研究的基础上，利用多基因分析法进行分子系统学研究，探索黑粉菌锈菌属种间系统发育关系，开展黑粉菌锈菌疑难种和近似种的分子鉴定，对于形态学难以识别的属种的界定提出分子证据。以黑粉菌锈菌标本为材料，用ITS、18S、28S rDNA、β-tubulin和 EF-1α基因片段，开展黑粉菌锈菌系统演化研究，进行DNA条形码研究探索，筛选适合黑粉菌锈菌的DNA条形码，实现快速、准确、可靠的黑粉菌锈菌物种鉴定。通过表型与基因型相结合的方法，建立黑粉菌锈菌更加贴近自然的分类系统，揭示藏东川西横断山区黑粉菌锈菌物种多样性，对锈菌黑粉菌区系组成和特征进行分析。该研究对中国菌物区系起源、形成和演化研究起重要作用；对黑粉菌锈菌物种资源和基因资源的保护、开发和利用，对病原真菌的防控具有重要的意义。

经过对西藏东部和四川西部横断山进行野外考察，采集黑粉菌锈菌标本1550号，经研究共获锈菌计14科45属379种，黑粉菌8属35种，隔担菌属10种，外担菌2种。对隔担菌属17个种，34号标本进行了分子生物学研究，表明担子的形态和数目，菌丝柱的高矮都是分类学的重要特征。从分子系统学角度对外担菌属22个种31条序列进行了研究，发现外担菌属种类之间的关系与寄主植物和症状有较强的对应关系，寄主专化性和症状应做为外担菌属分类的重要依据。锈菌区系属于泛北极区系，从生态地理特性来看，属于温带性质。