Inhibition de champignons phytopathogènes par des bactéries isolées du sol et de la rhizosphère de légumineuses

The antifungal activity of 644 bacterial isolates obtained from soil and from the rhizosphere of some leguminous plants was studied with one hyperparasite and six pathogenic fungi frequently associated with leguminous or gramineous plants. More than half (51.2%) of the bacterial isolates inhibited at least one fungus and 1.7% had an inhibitory effect on all the fungi tested. Stemphylium sarcinaeforme was the most sensitive fungus (inhibited by 27.0% of the bacteria tested), while Fusarium solani and Gliocladium roseum were the most resistant (inhibited by only 7.6 and 7.8% of the isolates, respectively). Verticillium albo-atrum and Fusarium oxysporum f. sp. medicaginis, important pathogens of alfalfa, were inhibited by 17.7 and 14.7% of the bacteria, respectively. Among the 166 bacteria showing the most important inhibitory effect on fungi, 7.2% inhibited strain A2 of Rhizobium meliloti and 21.1%, strain S14. In general, we obtained higher percentages of bacteria inhibiting fungi and Rhizobium meliloti fr...