PIRIFORMOSPORA INDICA, GEN. ET SP. NOV., A NEW ROOT-COLONIZING FUNGUS

A new fungus isolate was discovered in an arbuscular mycorrhizal funga l spore from a desert soil in India. It could easily be cultivated on various synthetic media, and formed pear-shaped chlamydospores. Inocul ation of maize showed that the fungus colonized the root cortex. Since it did not resemble any known fungus based on morphology and ultrastr ucture, a new genus was described. For its characteristic spore struct ure the isolate was named Piriformospora indica. Electron microscopy r evealed the presence of typical dolipores with continuous parenthesome s, which indicated that P. indica belongs to the Hymenomycetes (Basidi omycota). DNA was extracted and the 5' end of the 18S rRNA was amplifi ed and sequenced. Comparison with sequences from the Genbank data base indicated that P. indica is related to the Rhizoctonia group.