Effectiveness of indigenous and non-indigenous isolates of arbuscular mycorrhizal fungi in soils from degraded ecosystems and man-made habitats

Culturing in soils from degraded ecosystems significantly influenced the ef fectiveness of indigenous arbuscular mycorrhizal fungi (AMF) isolated from disturbed and undisturbed soils. The AMF isolates from degraded or artifici ally created habitats (acid rain polluted site, power station fly ash depos its, spoil banks, pyrite deposit), were not, in most cases, more effective than those from undisturbed soils, when grown in symbiosis with maize in th e disturbed soils. Significant effects of soil or substrate on plant growth were found, while the influence of the AMF inoculant was much less pronoun ced. The development of AMF isolates was reduced in soils with more adverse chemical properties irrespective of the isolate origin. The length of extr aradical mycelium of AMF and NADH-diaphorase activity of the mycelium were good indicators of negative effects of stress factors in the soil. (C) 2000 Elsevier Science B.V. All rights reserved.