Interactions between the soilborne root pathogen Phytophthora nicotianae var. parasitica and the arbuscular mycorrhizal fungus Glomus mosseae in tomato plants.

摘要

In a sand culture experiment, tomato cv. Earlymech plants were soil inoculated with Glomus mosseae and/or P. nicotianae var. parasitica. All plants were fed with a nutrient solution containing 32 (I P) or 96 muM P (II P) or were not inoculated (controls). Mycorrhizal plants had a similar development to that of control plants. Treatment with P. nicotianae var. parasitica resulted in a visible reduction in plant weight and in a widespread root necrosis in plants without mycorrhiza. The presence of theAM fungus decreased both weight reduction and root necrosis. The percentage reduction of adventitious root necrosis and of necrotic root apices ranged between 63 and 89%. P application increased plant development, but did not appreciably decrease disease spread. Mycorrhizal inoculation increased plant resistance to P. nicotianae var. parasitica infection.