Global diversity of the Tylopilus alboater complex (Boletaceae, Boletales): new genus and species, and typification of the name Boletus alboater

Recognition of Tylopilus alboater once relied heavily on the morphological features of the basidiomata, which resulted in considerable confusion due to morphological stasis and plasticity. In this study, we examined specimens morphologically identified as T. alboater from Asia, North America, and Australia using phylogenomics and multi-locus sequence data. To clarify its phylogenetic placement within Boletaceae, we conducted a phylogenomic analysis based on 45 genomes (including three newly sequenced T. alboater genomes) comprising representatives from the eight subfamilies of Boletaceae.

Additionally, we constructed a concatenated dataset (nrLSU + tef 1 - α + rpb 1 + rpb 2), incorporating representative species from all genera within the subfamily to which T. alboater belongs, to infer its phylogeny. Our phylogenomic analysis revealed that specimens morphologically identified as T. alboater exhibit polyphyly, clustering entirely within the subfamily Boletoideae. Our multi-locus phylogenetic analyses further indicated that these specimens represent eight distinct species distributed across five generic lineages within the subfamily Boletoideae, including one new genus, Neoporphyrellus, proposed in this study, as well as one new species, N. sinoalboater, and two new combinations, N. alboater and N. atronicotianus.

The remaining five species are nested in four known genera, including two new species of Abtylopilus, Ab. indonesiensis and Ab. australiensis, and three known species belonging to Anthracoporus, Indoporus, and Tylopilus, respectively. These findings highlight the taxonomic complexity of the T. alboater complex and emphasize the importance of integrating phylogenomic and multi-locus approaches for accurate fungal systematics.

Color photos of fresh basidiomata, line drawings of microscopic features, and detailed descriptions of the new taxa are presented.