Ecological fitness of the biocontrol agent Fusarium oxysporum Fo47 in soil and its impact on the soil microbial communities |
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Authors: | Véronique Edel-Hermann Sylvie Brenot Nadine Gautheron Sébastien Aimé Claude Alabouvette & Christian Steinberg |
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Institution: | INRA, Universitéde Bourgogne, UMR1229 Microbiologie du Sol et de l'Environnement, CMSE, Dijon, France |
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Abstract: | Some nonpathogenic strains of Fusarium oxysporum can control Fusarium diseases responsible for severe damages in many crops. Success of biological control provided by protective strains requires their establishment in the soil. The strain Fo47 has proved its efficacy under experimental conditions, but its ecological fitness has not been carefully studied. In a series of microcosm studies, the ability of a benomyl-resistant mutant Fo47b10 to establish in two different soils was demonstrated. One year after its introduction at two concentrations in the disinfected soils, the biocontrol agent (BCA) established at similar high population densities, whereas in the nondisinfected soils it survived at lower densities, related to the initial concentrations at which it was introduced. The BCA behaved similarly in the two soils at temperatures ranging from 5 to 25 °C and soil water potentials between −0.01 and −1.5 MPa. In addition, terminal restriction fragment length polymorphism analysis of 16S and 18S rRNA showed that the structures of the bacterial and fungal communities evolved with time but were not significantly affected by the introduction of the BCA. Overall, the results showed that Fo47 is potentially a good BCA, able to establish in different soil environments without perturbing the investigated microbial structures. |
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Keywords: | biological control ecological fitness Fusarium oxysporum Fo47 microbial community risk assessment terminal restriction fragment length polymorphism (T-RFLP) |
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