Resumo

APONTE, Glenda Y et al. In vitro evaluation of Trichoderma spp. isolates on mycelial growth of phytopathogenic fungi. Agronomía Trop. [online]. 2012, vol.62, n.1-4, pp.017-024. ISSN 0002-192X.

It has been shown that species of Trichoderma spp. produce secondary metabolites with antifungal activity, which constitutes a rate of several groups related to their structure and function, this groups contain volatile and nonvolatile components. We evaluated the metabolic activity of five isolates of Trichoderma spp. In vitro study we evaluated the affect of five isolates of Trichoderma spp. in control of Fusarium verticillioides, Rhizoctonia solani y Macrophomina phaseolina, wich are causes of the rot in corn stalks, banded stink in corn and charcoal rot in bean respectivelly. Antagonists isolates were collected from agricultural fiels of the Aragua, Carabobo and Guarico State and the were identifyined at the species level by morphological studies. To evaluate the mechanism of antibiosis, antagonists were grown in liquid culture medium potato-dextrose, reproduction took place statically, filtered separately using paper 100 μm, were centrifuged, the supernatant was filtered using paper 0.22 μm. In the filtrates were placed discs of PDA colonized with the pathogen, for a period of 15 days, then extracted mycelial mass developed and was dried in an oven at 30 °C for 3 days, then weighed and calculated the percentage of inhibition mycelial mass of each pathogen. The insulation provided better control of all pathogens was evaluated belonging to T. crassum 06141 (94.47%), followed by isolation of T. harzianum 06143 (92.35%), T. harzianum FTSC05 (91.94%), T. longibrachiatum Saman Mocho (85.86%) and T. harzianum 06146 (84.33%).

Palavras-chave : antagonistic; antibiosis; Fusarium verticillioides; Macrophomina phaseolina; Rhizoctonia solani; secondary metabolites.