Two new species and one new record of Xenosporium with ellipsoidal or ovoid conidia from Taiwan

Three species of Xenosporium producing ellipsoidal or ovoid conidia were collected from decaying culms of Miscanthus floridulus submerged in freshwater streams of Alishan area, Chiayi County, Taiwan. Xenosporium formosiforme and X. parvulum are described and illustrated as new species. Xenosporium africanum is described in this paper as a new record for Taiwan. The phylogenetic relationships of Xenosporium species and related taxa were sought by comparing the sequences of their internal transcribed spacer (ITS) barcode, 28S rDNA, and RNA polymerase II second largest subunit (RPB2) gene segments. Phylogenetic analysis of these Xenosporium species supports their placement in the Tubeufiaceae. A synopsis of Xenosporium species producing ellipsoidal or ovoid conidia is given. The criteria used to differentiate species are discussed.本研究从中国台湾省嘉义县阿里山地区淡水溪流中浸没的五节芒（Miscanthus floridulus）枯死茎秆上，采集到3株产椭圆形或卵形分生孢子的异孢霉属（Xenosporium）物种。其中，台湾异孢霉（Xenosporium formosiforme）与小型异孢霉（X. parvulum）作为新种被详细描述并附插图；非洲异孢霉（Xenosporium africanum）作为台湾地区新记录种被本文报道。本研究通过比对各菌株的内部转录间隔区（internal transcribed spacer, ITS）条形码序列、28S核糖体DNA（28S rDNA）以及RNA聚合酶II第二大亚基（RPB2）基因片段，解析了异孢霉属物种及其近缘类群的系统发育关系。针对上述异孢霉属物种的系统发育分析结果，支持其归入管囊霉科（Tubeufiaceae）。本文还整理了产椭圆形或卵形分生孢子的异孢霉属物种的分类概要，并讨论了该属物种的分类鉴别标准。