Molecular phylogeny and spore evolution of Entolomataceae

D. Co-David, D. Langeveld, M.E. Noordeloos

The phylogeny of the Entolomataceae was reconstructed using three loci (RPB2, LSU and mtSSU) and, in conjunction with spore morphology (using SEM and TEM), was used to address four main systematic issues: 1) the monophyly of the Entolomataceae; 2) inter-generic relationships within the Entolomataceae; 3) genus delimitation of Entolomataceae; and 4) spore evolution in the Entolomataceae. Results confirm that the Entolomataceae (Entoloma, Rhodocybe, Clitopilus, Richoniella and Rhodogaster) is monophyletic and that the combination of pinkish spore prints and spores having bumps and/or ridges formed by an epicorium is a synapomorphy for the family. The Entolomataceae is made up of two sister clades: one with Clitopilus nested within Rhodocybe and another with Richoniella and Rhodogaster nested within Entoloma. Entoloma is best retained as one genus. The smaller genera within Entoloma s.l. are either polyphyletic or make other genera paraphyletic. Spores of the clitopiloid type are derived from rhodocyboid spores. The ancestral spore type of the Entolomataceae was either rhodocyboid or entolomatoid. Taxonomic and nomenclatural changes are made including merging Rhodocybe into Clitopilus and transferring relevant species into Clitopilus and Entoloma.