PHYLOGENETIC ANALYSIS OF JAPANESE ARMILLARIA BASED ON THE INTERGENIC SPACER (IGS) SEQUENCES OF THEIR RIBOSOMAL DNA

To determine the phylogenetic positions of two new species, Armillaria jezoensis and Armillaria singula, and one new subspecies, Armillaria mellea subsp. nipponica, the nucleotide sequences of the intergenic sp acers (IGS) of their ribosomal DNA were investigated, and compared wit h those of four other Armillaria species from Japan, and those of nine Armillaria species from Europe and North America. We conclude that Ar millaria jezoensis, and Armillaria singula belong to the Armillaria ga llica cluster as Armillaria cepistipes, Armillaria gallica and Armilla ria sinapina from Japan. Two isolates of Armillaria ostoyae from Japan were placed within the Armillaria ostoyae cluster. Armillaria mellea subsp. nipponica had an IGS sequence as long as the IGS of Armillaria mellea from Europe and North America. However, the IGS sequences of Ar millaria mellea subsp. nipponica, whose basidium base lacks a clamp co nnection could not be satisfactorily aligned with the IGS sequences of other species possessing this morphological feature.