Notes on the Ecology and Distribution of Species of the Genera of Bondarzewiaceae (Russulales and Basidiomycota) with an Emphasis on Amylosporus

Abstract

The family Bondarzewiaceae is an important and diverse group of macrofungi associated with wood as white rotting fungi, and some species are forest tree pathogens. Currently, there are nine genera and approximately 89 species in the family, distributed in tropical, subtropical, and temperate climates. To address the phylogenetic relationships among the genera, a combined ITS-28S dataset was subjected to maximum likelihood (ML), Bayesian inference (BI), and time divergence analyses using the BEAST package. Both ML and BI analyses revealed two major clades, where one major clade consisted of Amylosporus, Stecchericium, and Wrightoporia austrosinensisa. The second major clade is composed of Bondarzewia, Heterobasidion, Gloiodon, Laurilia, Lauriliella, and Wrightoporia, indicating that these genera are phylogenetically similar. Wrightoporia austrosinensisa recovered outside of Wrightoporia, indicating that this species is phylogenetically different from the rest of the species of the genus. Similarly, time divergence analyses suggest that Bondarzewiaceae diversified around 114 million years ago (mya), possibly during the Early Cretaceous Epoch. The genus Amylosporus is well resolved within the family, with an estimated stem age of divergent around 62 mya, possibly during the Eocene Epoch. Further, the species of the genus are recovered in two sister clades. One sister clade consists of species with pileate basidiomata and generative hyphae with clamp connections, corresponding to the proposed section Amylosporus sect. Amylosporus. The other consists of species having resupinate basidiomata and generative hyphae without clamps, which is treated here as Amylosporus sect. Resupinati. We provided the key taxonomic characters, known distribution, number of species, and stem age of diversification of each section. Furthermore, we also described a new species, Amylosporus wadinaheezicus, from Oman, based on morphological characters of basidiomata and multigene sequence data of ITS, 28S, and Tef1-α. With pileate basidiomata and phylogenetic placement, the new species is classified under the proposed A. sect. Amylosporus. An identification key to the known species of Amylosporus is presented. Ecology and distribution of species of the genera in the family are discussed.