Ectomycorrhizas and molecular phylogeny of the hypogeous russuloid fungus Arcangeliella borziana

Sporocarps of Arcangeliella borziana, a hypogeous russuloid fungus, were fo und in a subalpine spruce forest in the Swiss Alps. We identified the ectom ycorrhizas formed by this species using the ITS-FCR-RFLP method and describ ed them in terms of morphological, anatomical, and molecular features. Phyl ogenetic placement of A. borziana was studied by comparing nucleotide seque nces of the mitochondrial large subunit rRNA gene and the ITS region of nuc lear rRNA, respectively, with existing sequence databases, and by comparing the ITS-RFLP pattern with a reference library of approx. 180 mainly basidi omycetous fungi. Sequence analysis of the mitochondrial large subunit rRNA gene confirmed the affiliation of A. borziana to the Russulaceae. Sequence as well as RFLP pattern comparison of the ITS region revealed a close affin ity of this species to Lactarius sect. Russularia. This is in accordance wi th morphological and anatomical studies of the ectomycorrhizas, which share many features with ectomycorrhizas of Lactarius sect. Russularia.