Endogone pisiformis: axenic culture and associations with Sphagnum, Pinus sylvestris, Allium cepa, and Allium porrum

Abstract

Endogone pisiformis is described in pure culture on various normal mycological media. The usually coenocytic mycelium is characteristically coloured yellow and bears numerous lipid-fllled hyphal swellings. Under axenic conditions, hyphae are attracted to Sphagnum, but the fungus has neither sporulated on nor parasitized the Sphagnum. Endogone pisiformis does not form ectomycorrhizae under the conditions studied with inoculated Pinus sylvestris although the fungus may survive in its rhizosphere. Germinated Allium porrum and Allium cepa seeds, moribund roots, and shoots were colonized by Endogone pisiformis which formed densely branched, fine hyphal structures and lipid-filled hyphal swellings within these plant tissues. The possibility is raised that these structures are homologous to the arbuscules and vesicles of vesicular–arbuscular mycorrhizal fungi. Examination of other Endogone species may elucidate the phylogeny of this genus.