Implications of Phylogenetic Studies for Conservation of Genetic Diversity in Shiitake Mushrooms

We consider the impact of recent molecular phylogenetic analyses on conservation issues for shiitake mushrooms. Bused on mating compatibility, shiitake has been considered a single species, Lentinula edodes sensu lato . Phylogenetic analyses of ribosomal RNA internal transcribed spacers (Hibbett et al. 1995), however, suggest that shiitake is composed of four distinct lineages. Thus, under a phylogenetic species concept, four species of shiitake should be recognized. A classification of shiitake based on a phylogenetic species concept would convey information about evolutionary relationships and distribution of genetic variation, whereas a classification based on a biological species concept would lack such information. This is a clear case in which new insights into phylogenetic relationships can be used to target areas for conservation action and formulate international agricultural policies. At the heart of our argument is the belief that the basic units of both taxonomy and conservation should be unique evolutionary lineages of organisms identified through phylogenetic studies.