Funneliformis huaxica, a new species of arbuscular mycorrhizal fungi (Glomeromycota) from Guiyang, China

A new species of Funneliformis (Glomerales, Glomeromycota), was isolated from rhizosphere soil of Uncaria rhynchophylla in the Huaxi District of Guiyang City, China. Phylogenetic analyses based on nuclear rDNA sequences (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) confirmed that this isolate represents an undescribed species. Morphological and molecular data support its recognition as a distinct species, here proposed as F. huaxica sp. nov. The fungus forms spores singly in soil. Spores are pale yellow, spherical, sub-spherical to ellipsoidal, and occasionally irregular in shape. The spore wall is composed of three layers: a hyaline, evanescent outer layer (0.5–2.5 μm thick); a laminate middle layer (pale yellow to yellow-brown, 0.4–1.5 μm thick, thickening to 4.5 μm at the base); and an inner layer (about 0.6 μm thick, pale yellow to yellow-brown) tightly adherent to the middle layer. None of the wall layers reacted with Melzer’s reagent. Funneliformis huaxica is morphologically and phylogenetically distinct from its closest relative, F. geosporum.