Cryptogamie, Mycologie
38 (1) - Pages 27-53The diversity of lignicolous freshwater fungi along a north-south latitudinal gradient are currently being studied in Asia. In this paper, we report on 18 collections of asexual morphs of Tubeufiaceae from submerged wood in rivers, streams and a lake in Yunnan Province, China. Taxa are characterized based on morphological characters and analyses of ITS, LSU and TEF1α sequence data. The new genera, Muripulchra with a single species, M. aquatica and Neohelicomyces with three new taxa (N. aquaticus, N. grandisporus, N. submersus) are introduced. Muripulchra is characterized by micronematous conidiophores and obpyriform, septate to muriform conidia. Neohelicomyces is characterized macronematous conidiophores and multi-septate, helicoid conidia. Tubeufia aquatica is introduced as a new species and its phylogenetic relationships with other taxa is discussed. The phylogenetic analyses of a concatenated ITS, LSU and TEF1α dataset place all collections in the family Tubeufiaceae (Tubeufiales) and provide evidence to support the establishment of our new taxa. The asexual morph of Tubeufia cylindrothecia, the type species of Helicomyces (H. roseus) are described herein, phylogenetic relationships assessed and reference specimens are given for these two species. Descriptions and illustrations for the new genera and species are provided with notes on their taxonomy and phylogeny.
