Studies in the Basidiodendron caesiocinereum complex (Auriculariales, Basidiomycota)

Ilya Viner,Heikki Kotiranta,Nathan Schoutteten,Michael Weiß,Viacheslav Spirin,Annemieke Verbeken,Jenni Nordén,Otto Miettinen,Karl-Henrik Larsson,Leif Ryvarden,Vera Malysheva

doi:10.1007/s11557-021-01724-6

Abstract

Taxonomy of Basidiodendron caesiocinereum complex is revised based on morphological and molecular methods (with the use of nc LSU rDNA, ITS and TEF1 regions). The basidiospore ornamentation is justified as a key morphological character for the species recognition in the group. As redefined here, B. caesiocinereum is an angiosperm-dwelling species with smooth basidiospores. Bourdotia cinerella and B. cinerella var. trachyspora are proved to represent separate species with warted basidiospores; they are reintroduced as Basidiodendron cinerellum and B. trachysporum. Additionally, eight new species related to B. caesiocinereum are described based on material from Eurasia, North America and Africa, and identity of B. spinosum from Oceania is discussed.

Highlights

For almost two centuries, the basidiospore features, e.g. their shape, size, colour and ornamentation, have remained among the main features for morphological recognition of the basidiomycetous taxa
The overall topologies of the maximum likelihood (ML) and BI trees were nearly identical (Fig. 1). They uncovered all B. caesiocinereum s. lato specimens involved in the analyses in one strongly supported clade with B. luteogriseum Rick and members of the B. eyrei complex
The larger subclade contained sequences of specimens morphologically identical to the type material of B. caesiocinereum and B. caesiocinereum var. trachysporum. These taxa should be accepted as two separate species; as a consequence, B. caesiocinereum var. trachysporum is raised to the species level

Summary

Introduction

The basidiospore features, e.g. their shape, size, colour and ornamentation, have remained among the main features for morphological recognition of the basidiomycetous taxa. Almost all members of the Auriculariales (Basidiomycota) have small or medium-sized, colourless (hyaline), smooth basidiospores and three species with ornamented (warted or spiny) basidiospores have been so far detected in the genus Basidiodendron Rick (Wojewoda 1981). & Litsch.) Luck-Allen, was reported from different geographic areas of the world (Wells and Raitviir 1975). As re-defined by Luck-Allen (1963), the genus Basidiodendron Rick embraces effused wood-inhabiting fungi with smooth or minutely warted hymenophore, prominent gloeocystidia and longitudinally septate, predominantly fourcelled basidia. It differs from the morphologically similar genus Bourdotia (Bres.) Bres. Recent phylogenetic studies confirmed that Basidiodendron and Bourdotia should be treated as separate

Methods

Results

Conclusion