GENE PHYLOGENY OF THE GANODERMA-LUCIDUM COMPLEX BASED ON RIBOSOMAL DNA-SEQUENCES - COMPARISON WITH TRADITIONAL TAXONOMIC CHARACTERS

A gene phylogeny of 29 isolates of the G. lucidum complex collected in temperate and subtropical areas was produced by parsimony analysis fr om nucleotide sequence data of the internal transcribed spacer region of the ribosomal gene and from divergent domain D2 of the large riboso mal subunit gene, and serves as hypothesis of natural relationships be tween taxa. Results were compared with morphological, ecological, cult ural and mating data. They show that extensive convergence or parallel ism of morphological characters has occurred during Ganoderma evolutio n, but also that remarkable morphological difference may occur with li ttle divergence time. Monophyletic groups correlate fairly well with g eographical origin of the taxa and/or host relationships. Phylogenetic ally related isolates have similar culture characteristics, but they m ay share these characteristics with distant taxa. Therefore, culture c haracters are less polymorphic than morphological characters between r ecently diverged taxa, but are useless in recognizing monophyletic gro ups. Isolates belonging to the same biological species were monophylet ic with one exception. A species concept based on monophyly and potent ial evidence of genetic isolation is proposed, and taxonomy of the G. lucidum complex is revised. Collections named G. lucidum in North Amer ica and in Asia are not conspecific with European G. lucidum. The sist er group of European G, lucidum is an Argentinian taxon labelled G. oe rstedii. North American G. lucidum is related to a Formosan isolate id entified as G. boninense. G, tsugae is absent from Taiwan and probably also from Japan and China, although it was commonly reported there. G . tsugae belongs to a lineage restricted to coniferous forests in the more Northern latitudes, of which the taxonomy remains unresolved (the G. valesiacum complex). Correct naming and distribution of several ta xa are still to be investigated. From observation of distribution of t axa within monophyletic groups it is speculated that laccate Ganoderma may have originated in the tropics.