Kovács Gábor M, Trappe James M, Alsheikh Abdulmagid M, Bóka Károly, Elliott Todd F
Department of Plant Anatomy, Eötvös Loránd University, Pázmány Péter sétány 1/C, 1117 Budapest, Hungary.
Mycologia. 2008 Nov-Dec;100(6):930-9. doi: 10.3852/08-023.
Originally described from Japan by Sanshi Imai in 1933, the hypogeous ascomycete Terfezia gigantea was subsequently discovered in the Appalachian Mountains of the USA. Morphological, electron microscopic, and phylogenetic studies of specimens collected in both regions revealed that, despite this huge geographic disjunction, (1) the Japanese and Appalachian specimens are remarkably similar both in morphology and the sampled rDNA sequences, (2) the species unambiguously falls into the Morchellaceae and is separated from the genus Terfezia in the Pezizaceae, (3) its spores are much larger than those of Terfezia spp. and are enclosed in a unique, electron-semitransparent, amorphous epispore that appears to be permeated with minute, meandering strands or canals. In addition to the molecular phylogenetic results, the numerous nuclei in ascospores, the dome shaped, striate ascus septal plugs and the long cylindric Woronin bodies also strengthen the family assignment to the Morchellaceae. Moreover, the species occurs in moist, temperate forests as opposed to the xeric to arid habitats of other Terfezia spp. We propose the new, monotypic genus Imaia to accommodate the species.
地下子囊菌巨大块菌最初由今井参史于1933年在日本描述，随后在美国阿巴拉契亚山脉被发现。对在这两个地区采集的标本进行的形态学、电子显微镜和系统发育研究表明，尽管存在巨大的地理间断，（1）日本和阿巴拉契亚的标本在形态和采样的核糖体DNA序列上都非常相似，（2）该物种明确属于羊肚菌科，与盘菌科的块菌属分开，（3）其孢子比块菌属物种的孢子大得多，并被包裹在一种独特的、电子半透明且无定形的外孢壁中，外孢壁似乎布满了微小的蜿蜒丝或管道。除了分子系统发育结果外，子囊孢子中的大量细胞核、圆顶形、有条纹的子囊隔膜塞和长圆柱形的伏鲁宁体也强化了其属于羊肚菌科的分类地位。此外，该物种生长在潮湿的温带森林中，与其他块菌属物种的干旱至干燥生境相反。我们提议建立新的单型属伊迈块菌属来容纳该物种。
