Systematics and Phylogeny of Fungi in the Rhizoctonia Complex

Abstract

The taxonomic position of seven basidial genera of the Rhizoctonia complex is discussed. Thanatephorus, Ceratobasidium, Uthatobasidium, Waitea, and Aquathanatephorus are included in the Ceratobasidiaceae and Botryobasidium and Athelia in the Corticiaceae. A new genus Aquathanatephorus Tu and Kimbrough, based on the species A. pendulus, is proposed. Ceratobasidium Rogers is emended to contain a clamp-bearing species, C. fibulatum sp. nov. Two new species combinations, T. sasakii (Shirai) Tu and Kimbrough and Athelia rolfsii (Cruzi) Tu and Kimbrough are also proposed. Phylogeny, based on basidial septation and morphology and on ultrastructure of the septal pore structure, is discussed.