Systematic revision, molecular phylogeny and divergence times of Thelephorales (Basidiomycota)

Thelephorales is an important order of macro-fungi belonging to Basidiomycota. Species in this order play an essential role in the biogeochemical cycle in forest ecosystems and bring an essential economic value in developing and utilizing edible and medicinal fungal resources. In this study, the classification system of Thelephorales was revised based on morphological and phylogenetic analyses. The DNA sequences of multiple loci, including the internal transcribed spacer (ITS) regions, the large subunit of nuclear ribosomal RNA gene (nLSU), the small subunit of nuclear ribosomal RNA gene (nSSU), and the second largest subunit of RNA polymerase II gene (RPB2) were used to construct phylogenetic relationships and infer the divergence time of Thelephorales. The phylogenetic analyses revealed that six clades at the family level were obtained in Thelephorales with high supports. The ancestor of Thelephorales split at about 269.07 Mya, and the mean stem ages of the families of Thelephorales were centralized differentiation in 145.95– 269.07 Mya. Combined with morphological studies, Thelephorales were confirmed to comprise six families, including four new families: Lenzitopsidaceae, Polyozellaceae, Sarcodonaceae, Tomentellopsidaceae, and two existing families: Bankeraceae and Thelephoraceae. There are twelve identified genera viz. Amaurodon, Boletopsis, Corneroporus, Hydnellum, Lenzitopsis, Neosarcodon, Odontia, Sarcodon, Phellodon, Polyozellus, Thelephora, and Tomentellopsis. Furthermore, 20 new species were described, and 4 new combinations were proposed. Illustrated descriptions and scanning electron micrographs of the basidiospores of the new species were provided. Keys to Thelephorales and the accepted families, and the notes of the accepted genera in Thelephorales were also provided.