Glomus Chinense and Dominikia Gansuensis, Two New Glomeraceae Species of Arbuscular Mycorrhizal Fungi From High Altitude in The Tibetan Plateau

Two glomoid spore-producing arbuscular mycorrhizal fungi were grown in single-species cultures established from soil-borne spores collected from high altitude (2,800 m a.s.l.) of Tibet Plateau, China. Phylogenetic analyses were performed with sequences of nuclear rDNA (spanning the partial small subunit, whole internal transcribed spacer, and partial large subunit segment = 18S-ITS-28S) and the largest subunit of RNA polymerase II (RPB1) gene. Morphological and phylogenetic analyses indicated that the two fungi are undescribed species of the genera Glomus and Dominikia. The first fungus, described here as G. chinense sp. nov., formed spores singly and in loose clusters. The spores are orange-yellow to dark brown, globose, (47–)64(–93) µm diam. Dominikia gansuensis sp. nov. produced glomerocarps with pale yellow to yellow-brown, globose, (20–)47(–86) µm diam spores. Spore wall of both species consists of three layers. Both species differ clearly in morphology and phylogeny from their closest phylogenetic relatives, which are G. atlanticum and G. ibericum, and D. glomerocarpica, respectively.