Phylogeny of the genusLentinulabased 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 with out-groups Clitocybula, Collybia and Pleurotus, were used for a phylogenetic analysis. A phylogeny based on data from the transcribed rDNA regions supports the monophyly of the genus Lentinula. Lentinula species display a comparatively low level of estimated nucleotide divergence relative to the outgroup species studied. The Asian-Australasian-distributed species (L. edodes, L. lateritia, and L. novaezelandiae) and the American-distributed L. boryana belong to two distinct genetic groups, with about 1.89% nucleotide divergence from each other. The Asian-Australasian species of Lentinula were approximately 4.0% divergent from the P. ostreatus and Collybia dryophila out-groups, while L. boryana was only approximately 3.5% divergent. Lentinula boryana is postulated to be the earliest lineage to diverge within the genus Lentinula, while the remaining Asian-Australasian species are suggested to have evolved more recently. This molecular phylogeny highlights the phylogenetic differences between the Asian-Australasian species of Lentinula and supports their most recent classification based morphological characters.