PHYLOGENY OF THE GENUS LENTINULA BASED ON RIBOSOMAL DNA RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM ANALYSIS

RFLP data from PCR amplified regions of the rDNA repeat from Lentinula edodes, L. boryana, L. lateritia, and L. novaezelandiae, together wit h outgroups Clitocybula, Collybia and Pleurotus, were used for a phylo genetic analysis. A phylogeny based on data from the transcribed rDNA regions supports the monophyly of the genus Lentinula. Lentinula speci es display a comparatively low level of estimated nucleotide divergenc e relative to the outgroup species studied. The Asian-Australasian-dis tributed species (L. edodes, L. lateritia, and L. novaeselandiae) and the American-distributed L. boryana belong to two distinct genetic gro ups, with about 1.89% nucleotide divergence from each other. The Asian -Australasian species of Lentinula were approximately 4.0% divergent f rom the P. ostreatus and Collybia dryophila outgroups, while L. boryan a was only approximately 3.5% divergent. Lentinula boryana is postulat ed to be the earliest lineage to diverge within the genus Lentinula, w hile the remaining Asian-Australasian species are suggested to have ev olved more recently. This molecular phylogeny highlights the phylogene tic differences between the Asian-Australasian species of Lentinula an d supports their most recent classification based morphological charac ters.