Molecular phylogenetics of Ramaria and related genera: evidence from nuclear large subunit and mitochondrial small subunit rDNA sequences

Phylogenetic relationships of the genus Ramaria and additional related taxa were examined through phylogenetic analysis of mitochondrial and nuclear r ibosomal DNA sequence data. Related genera included Clathrus, Clavariadelph us, Gautieria, Gomphus, Hysterangium, Kavinia and Pseudocolus. Outgroup gen era included Bondarzewia, Favolus, Ganoderma, Lactarius and Russula. The nu clear large subunit ribosomal DNA (nuc LSU rDNA) (approx. 610 bp) from 78 c ollections including 34 Ramaria species was used to test generic, subgeneri c and selected species concepts for Ramaria. The mitochondrial small subuni t ribosomal DNA (mt SSU rDNA) (ca 470 bp) from 51 representative holobasidi omycetes including ten Ramaria species also was used to independently test the monophyly of the genus Ramaria. Parsimony analyses of both datasets ind icated that the genus Ramaria was paraphyletic and that several morphologic ally distinct groups of holobasidiomycetes were derived from ramarioid ance stors. In the nuc LSU rDNA analyses, Gautieria was nested among the terrico lous Ramaria species and was closely related to R. subg Ramaria. The nuc LS U rDNA results also indicated that R subg Laeticolora and R. subg Lentorama ria formed paraphyletic grades. Ramaria subg Laeticolora was paraphyletic d ue to the terminally derived R. subg Ramaria/Gautieria clade and a nested G omphus. Ramaria subg Lentoramaria was paraphyletic due to a nested Clavaria delphus, Kavinia, and R. abietina of subg Echinoramaria. Both the nuc LSU r DNA and the mt SSU rDNA analyses demonstrated strong bootstrap support for the inclusion of the Phallales with the ingroup taxa, but the relationship of the Phallales to the Gomphales was indeterminate. Selected species conce pts were also tested (e.g., R amyloidea and R. celerivirescens, and R. arai ospora and R. stuntzii). These data rejected the monophyly of Ramaria and s uggested that the ramarioid morphology and lignicolous substrate affinity w ere ancestral for the Gomphales.