Dependence of Allium fistulosum cultivars on the arbuscular mycorrhizal fungus, Glomus fasciculatum

We screened 27 cultivars of Welsh onion (Allium fistulosum) for dependency on arbuscular mycorrhizal colonisation. Root length was different among cultivars. All cultivars were well colonised with Glomus fasciculatum, the percentage mycorrhizal colonisation ranging from 48 to 81%. Shoot phosphorus (P) uptake and dry mass of plants increased with mycorrhizal colonisation and mycorrhizal dependency of shoot growth ranged from 73 to 95%. There were negative correlations between the specific P uptake of nonmycorrhizal plants and mycorrhizal dependencies of shoot P uptake and shoot growth. Cultivars of Sydney Bunching, Winter over, Vilr-Moscow, CibouleC9379 and Kagoshimahanegi showed higher dependency of growth on mycorrhizal colonisation and these were considered to be highly mycotrophic cultivars. (C) 2001 Elsevier Science B.V. All rights reserved.