Morphological reassessment and molecular phylogenetic analyses of Amauroderma s.lat. raised new perspectives in the generic classification of the Ganodermataceae family

Abstract

Ganodermataceae is a remarkable group of polypore fungi, mainly characterized by particular double-walled basidiospores with a coloured endosporium ornamented with columns or crests, and a hyaline smooth exosporium. In order to establish an integrative morphological and molecular phylogenetic approach to clarify relationship of Neotropical Amauroderma s.lat. within the Ganodermataceae family, morphological analyses, including scanning electron microscopy, as well as a molecular phylogenetic approach based on one (ITS) and four loci (ITS-5.8S, LSU, TEF-1α and RPB1), were carried out. Ultrastructural analyses raised up a new character for Ganodermataceae systematics, i.e., the presence of perforation in the exosporium with holes that are connected with hollow columns of the endosporium. This character is considered as a synapomorphy in Foraminispora, a new genus proposed here to accommodate Porothelium rugosum (≡ Amauroderma sprucei). Furtadoa is proposed to accommodate species with monomitic context: F. biseptata, F. brasiliensis and F. corneri. Molecular phylogenetic analyses confirm that both genera grouped as strongly supported distinct lineages out of the Amauroderma s.str. clade.

Multi-gene phylogeny and taxonomy of Amauroderma s. lat. (Ganodermataceae)

“…Since this feature is not in accordance with the current circumscription of Amauroderma s.str., this species was not included in this key. Notes -Foraminispora was established by Costa-Rezende et al (2017) and only Fo. rugosa from the Neotropics was included.…”

“…have a dull to laccate pileal surface, a fresh pore surface colour unchanging when bruised, a dimitic hyphal system and non-dextrinoid or dextrinoid basidiospores with solid endospore ornamentation (Ryvarden 2004, Gomes-Silva et al 2015, Costa-Rezende et al 2017). Up to now, Foraminispora was considered as a monotypic genus, composed only by F. rugosa from Neotropics (Costa-Rezende et al 2017). During the study of basidiospores ultrastructure of tropical and subtropical species previously classified in Amauroderma (A. austrosinense, A.…”

“…Taxonomic and phylogenetic studies of Ganodermataceae have been carried out in recent years, but most studies focused on Ganoderma ( Smith & Sivasithamparam 2000 , Hong & Jung 2004 , Pilotti et al 2004 , Wang et al 2009 , Cao et al 2012 , Cao & Yuan 2013 , Li et al 2014b , Lima Júnior et al 2014 , Coetzee et al 2015 , Hapuarachchi et al 2015 , Xing et al 2016 , Xing et al 2018 , Thawthong et al 2017 ) and only a few studies dealt with Amauroderma ( Gomes-Silva et al 2015 , Costa-Rezende et al 2016 , 2017 , Song et al 2016 ). Regarding this phylogenetic context, Amauroderma has been pointed as polyphyletic and regarded as Amauroderma s.lat., in which Amauroderma s.str.…”

“…Regarding this phylogenetic context, Amauroderma has been pointed as polyphyletic and regarded as Amauroderma s.lat., in which Amauroderma s.str. has been defined as a Neotropical clade ( Gomes-Silva et al 2015 , Costa-Rezende et al 2016 ); as for the relevance of hyphal system composition and basidiospore ultrastructure for generic delimitation in the group was observed, as well as two new genera called Foraminispora and Furtadoa were proposed ( Costa-Rezende et al 2017 ). Furthermore, the generic status of Amauroderma s.lat.…”

“…rugosum and A . perplexum ; and ‘ Amauroderma yunnanense clade’ composed by A. yunnanense ( Costa-Rezende et al 2017 ), as well as a variety of Asian and African species which were not phylogenetically tested. In this study, taxonomic and phylogenetic analyses of Amauroderma s.lat.…”