Two new species of Pseudogymnoascus with Geomyces anamorphs and their phylogenetic relationship with Gymnostellatospora
Two new species of Pseudogymnoascus with Geomyces anamorphs and their phylogenetic relationship with Gymnostellatospora
复制标题
DOI：
10.3852/mycologia.98.2.307
复制
发表时间：
2006-03-01
期刊：
影响因子：
2.8
通讯作者：
Currah, Randolph S.
中科院分区：
文献类型：
--
作者：
Rice, Adrianne V.;Currah, Randolph S.
描述了采自加拿大阿尔伯塔泥炭藓沼泽的两个新的嗜冷假裸藻种。具长而分枝的橙子状附属物和光滑的梭形至椭圆形的子囊孢子，有一个微弱的纵缘。疣状假裸盖菌具有短的近透明附属物和疣状的周壁菌丝和子囊孢子，以及光滑到粗糙和不规则疣状的分生孢子。这两个物种都产生连锁的子囊，这一特征支持了这一群体与单独产生子囊的粘丝菌之间的区别。在Pseudogymnostellatospora和Gymnostellatospora之间发现了一个中间物种，既有成熟的子囊孢子，又有无性的Geomyces，这促使了对该属的重新评估。核核糖体DNA的内转录间隔区（ITS）的序列分析表明，这两个属仍然是不同的，包括一个单系群。假裸孢菌属（Pseudogymnospora）的孢子具光滑到疣状或裂片网状的子囊孢子，而Gemnostellatospora的孢子具明显的纵脊和条纹的核桃状孢子。可归属于Geomyces属的无性型与这两个属都是近缘的。本文提供了拟裸子蕨属四种和变种的检索表。
Two new psychrophilic Pseudogymnoascus species with Geomyces anamorphs are described from a Sphagnum bog in Alberta, Canada. Pseudogymnoascus appendiculatus has long, branched, orange appendages and smooth, fusoid to ellipsoidal ascospores with a faint longitudinal rim. Pseudogymnoascus verrucosus has short, subhyaline appendages and warty peridial hyphae and ascospores, and both smooth to asperulate and irregularly warty conidia. Both species produce asci in chains, a feature that supports the distinction between this group and Myxotrichum, which produces asci singly. The discovery of species intermediate between Pseudogymnoascus and Gymnostellatospora, in having both ornamented ascospores and Geomyces anamorphs, prompted a re-evaluation of the genera. Sequence analysis of the internal transcribed spacer regions (ITS) of the nuclear ribosomal DNA indicates that the two genera remain distinct and comprise a monophyletic group. Pseudogymnoascus species have smooth to warty or lobate-reticulate ascospores while species of Gemnostellatospora have walnut-shaped spores with distinct longitudinal crests and striations. Anamorphs assignable to the form genus Geomyces are allied with both genera. A key is provided to the four species and varieties of Pseudogymnoascus.