Molecular phylogeny of Japanese Amanita species based on nucleotide sequences of the internal transcribed spacer region of nuclear ribosomal DNA

The molecular phylogeny of 36 specimens of Japanese Amanita species was studied based on nucleotide sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. The phylogenetic tree obtained supported the traditional classification systems of Bas (1969) and Singer (1986), which are based on morphological characters, in the division of the genus Amanita is divided into subgenera Amanita and Lepidella by the amyloidity of basidiospores. However, at section-level, we suggest that subgenus Amanita should be divided into three sections (Amanita, Vaginatae, and Caesareae). Our results also showed the necessity to modify the taxonomic treatments at section-level in the subgenus Lepidella. It appears that the establishment of A. muscaria and A. pantherina from a common ancestral species might be a very recent event, or these might be lower taxa of same species. As for three subspecies of A. hemibapha and three varieties ofA. vaginata, it is necessary to grade up their taxonomical ranks from subspecies/variety to species. A new combination, A.javanica, is proposed forA. hemibapha subsp.javanica.