Resumo

Fungi of the genus Trichoderma are known biocontrol agents that act on the solubilization of nutrients, activation of the plant defense system, inducing the production of plant hormones and mycoparasitism. This work aimed realize the characterization morphophysiological, antagonism capacity antagonism (hyperparasitism and volatile metabolites) against Fusarium oxysporum f. sp. passiflorae, and molecular identification in the ITS region of Trichoderma isolates originating from agricultural soils of 11 counties in the northern state of Maranhão (Brazil). The chemical parameters of pH and matter of the soil samples were analyzed. In antagonism tests the results were evaluated by turkey to 5%. Total DNA was extracted, amplified with primers ITS 1 and 4 and sequenced. A total of 38 isolates were collected and classified in seven species: T. asperellum, T. harzianum, T. aggressivum, T. konilangbra, T. fertile, T. ghanense and T. atroviride. After that we selected 11 isolates for sequencing followed by analyses using Trichokey. The chemical parameters of the soil showed acid pH values, which probably were favorable for the fungal development, although the values of organic matter were considered low in all the soil samples counties. The results of hyperparasitism and volatile metabolites evidenced that all isolates were capable of inhibiting the mycelial growth of F. oxysporum f. sp. passiflorae. The phylogenetic analysis reveals which the isolates of T. asperellum formed a single grouping. The specie T. konilangbra was grouped with the North American variations, while T. harzianum was grouped with USA isolates. We emphasize that this is perhaps the first report of the occurrence of the T. konilangbra in Brazil, showing the importance of performing research in neglected regions for studies involving your presence.