中国地下子囊菌新记录属——史蒂芬块菌属（英文）

Stephensia( Pyronemataceae,Pezizales),a New Record of Chinese Hypogeous Ascomyctete

摘要：文中首次报道了史蒂芬块菌属Stephensia在中国的分布。史蒂芬块菌发现于滇中地区呈贡县，生于1株栽培的天麻旁边，附近长有云南松和榛属植物。标本的特征与文献中对于该种的描述一致，即子囊果表面具褐色绒毛，产孢组织有曲折的脉沟，脉沟向中心辐聚，中心有时形成空腔，孢子球形，直径18～25μm，无油滴，包被（外囊盘被）角胞组织。中国标本的ITS序列与北美和欧洲样品有99％的相似性，其LSU序列仅有3个碱基与北美样品不同。史蒂芬块菌在分子系统上与腔囊块菌属Hydnocystis和地杯菌属Geopxyis近缘。

Stephensia bombycina, collected from Chenggong County, central Yunnan, China, is fruited by a plant of Gastrodia elata, with Pinus yunnanensis and Corylus sp. nearby. This is the first report of the genus Stephensia in China. The Chinese sample has the following key characters of S. bombycina： brownish tomentose surface of the ascomata, interior with meandering canals conver- ging or communicating with a well-defined central cavity, globose, hyaline, eggutulate spores 18- 25μm in diam., and peridium with a pseudoparenchymatous cortex. ITS sequence of the Chinese sample is 99% similar to those of North American and European samples and LSU sequence of this sample has only three base pairs different from that of the North American sample. Phylogenetically, this species is closely related to the hypogeous genus Hydnocystis and epigeous genus Geopxyis.