中国口蘑科的系统发育与属种多样性研究

Fungi of Tricholomataceae are not only of important ecological value, but also of economic and scientific values. Most species within the family form ectomycohrrizal symbioses with various tree species, benefiting a wide range of forest trees. Tricholoma matsutake and many others are well-known edible or medicinal mushrooms, while T. equestre and several other species are toxic and may cause poisoning or even death. The family Tricholomataceae was once an “all-embracing” large family, but recent molecular phylogenetic evidence indicated that Tricholomataceae in its narrow sense, including about 300 species in eight genera, is a more natural and monophyletic group than previously thought. However, the relationships among the genera within the family in its narrow sense are largely unclear, and even the delimitation of Tricholomataceae s. str. itself is unsettled. The infrageneric treatment and species delimitation within the species-rich genus Tricholoma are still controversial. The knowledge about the diversity of the genera and species of the family in China is seriously scanty. Based on large-scale sampling of ca. 120 representative species of the genera, this project intends to employ integrated and inter-disciplinary approaches including field-ecological observation, morphological-anatomical characterization, molecular phylogenetic analyses of multigene nucleotide sequences, and phylogenomic data to study the phylogeny of Tricholomataceae. The goals of this study are: 1) to elucidate limits of the family and the evolutionary phylogenetic relationships among the genera within the family, 2) to put forward delimitation standards of the genera and species, and 3) then to document the genera and species in China. This study is of important scientific significance in understanding the limits of the family, the relationships among the genera within the family, and the diversity of the genera and species in China. Furthermore, this research has important application value in rational utilization and effective protection of edible mushroom resources, as well as in prevention from toadstool poisoning.

口蘑科真菌具有重要的生态价值、经济价值和科研价值，多数物种为许多树木生长必需的外生菌根菌，松口蘑等不少物种又是著名的食用菌或药用菌，油口蘑等物种误食会导致中毒或危及生命。该科曾是个包罗万象的大科，但新近分子系统发育证据表明狭义的口蘑科较为自然，共8属约300种。然而，口蘑科内各属之间的系统发育关系并不清晰，即便是狭义口蘑科的范围也仍没有定论，其中物种丰富的口蘑属的属下分类和物种划分仍然存在较大争议，我国对该科的属种多样性的认识就更加欠缺。本项目拟在大量取样（各属代表种共约120种）基础上，利用生态观察、形态解剖、分子系统发育、系统发育基因组等多种方法，综合研判该科的系统发育问题，阐明该科的界限和科下各属之间以及属内的演化谱系和系统亲缘，提出属种划分标准，精准界定属种。本研究对揭秘口蘑科的范围、属间关系及我国该科的物种多样性具有重要科学意义，对食用菌资源保护利用和毒菌预防具有重要应用价值。

口蘑科真菌具有重要生态、经济和科研价值，目前一般认为该科有9属约300种。但该科内各属之间的系统发育关系并不清晰，该科大属口蘑属的属下分类仍有争议，我国该科的属和种的多样性认识十分不足。本项目利用形态、生态、分子系统发育、系统发育基因组等多种方法，研究了全球该科9属120余种的800余份样品，发现口蘑科共有11个属级支系，其中皮蘑属（Dermoloma）可能分为3个独立的属较为合理，钉伞属（Porpoloma）与德尼斯伞属（Dennisiomyces）和科耐伞属（Corneriella）较近为近缘。根据多基因系统发育分析，发现囊泡杯伞属（Singerocybe）宜放于杯伞科（Clitocybaceae）；根据1340个直系同源基因系统发育分析，拟口蘑属（Tricholomopsis）应置于新建立的拟口蘑科（Tricholomopsidaceae）中。利用50个DNA分子片段的核苷酸序列，首次成功对口蘑属（Tricholoma）的系统发育框架进行了研究，揭示了深度分支之间的亲缘关系，发现该属分为4个亚属14个组较为妥当，新建了棕灰口蘑亚属（subg. Terrea）、黄绿口蘑组（sect. Fucata）和松口蘑组（sect. Matsutake），将subg. Contextocutis归并到口蘑亚属中，将巨口蘑组（sect. Megatricholoma）归并到原发口蘑组（sect. Genuina）中，提出了该属的新分类系统。发现我国现知该科3属（口蘑属、白桩菇属Leucopaxillus和假口蘑属Pseudotricholoma）共计80余种，新增约50%的物种，其中至少40余新种（本项目已发表其中13个新种）。我国该科真菌有18种可食，16种有毒。迄今，本项目发表SCI论文4篇（含接受发表2篇），另有1篇正在审稿中；获省部级科技进步奖二等奖1项；在全国和省级专业学术会议上作大会或分会报告共计5次；培养博士后2名、博士生和硕士生各1名，项目主要成员1人从中级晋升为副高；举办“真菌基因组和宏基因组学讲习班”1次。本研究对认识口蘑科的范围、科内属间关系及我国该科的属种多样性具有重要科学意义，对食用菌资源可持续利用和毒菌中毒预防和治疗具有重要应用价值。