Phylogenetic relationships of Termitomyces and related taxa.

Phylogenetic relationships of termitophilic fungi were estimated with Bayesian as well as other phylogenetic methods from partial sequences of the nuclear encoded large subunit ribosomal DNA (nLSU-rDNA) and the mitochondrial encoded small subunit ribosomal DNA (mtSSU-rDNA). Sequences were obtained from basidiomes covering the morphological, taxonomical, and geographical span of termitophilic mushroom-forming fungi, and analysed together with sequences from termite nests and termite guts from most known genera of fungus growing termites from geographically diverse regions. Topologies of trees resulting from the combined analyses of the two ribosomal genes generally show no positive conflicts with those obtained from separate analyses. We show that termitophilic fungi constitute a strongly supported monophyletic group within lyophylloid species. The genera Sinotermitomyces and Podabrella are derived within Termitomyces, and do not form monophyletic groups. Identical sequences were frequently found among samples of basidiomes from the same continents and among fungi utilized by termites from the same continent. However, only two sequences were identical between basidiome samples and termite nest/gut samples suggesting fruiting species do not form a representative sample of termitophilic fungi. No sequences were identical between samples from Asia and Africa indicating some geographic differentiation between these continents.