The phytopathogen Fusarium oxysporum, belonging to the genus that causes the disease
popularly known as fusariosis or Fusarium wilt, affects several agricultural crops worldwide.
Its high degree of pathogenicity is associated with its ability to colonize the vascular system of
plants, as well as the production of resistance structures in the soil, the chlamydospores.
Considering the need for methods that contribute to agricultural development without causing
damage to the environment and the population, biological control agents (BCAs) are now seen
as an excellent artifice. Fungi of the genus Trichoderma can be considered cunning BCAs
because they have numerous mechanisms with high antagonistic potential that impair spore
germination, hyphal growth and chlamydospore development of various phytopathogens. The
present work sought to evaluate the efficiency of Trichoderma spp. in the biocontrol of the
phytopathogen F. oxysporum through pairing tests, enzymatic analysis, and production of
secondary metabolites. All isolates had results considered satisfactory, according to the Bell
scale, in the pairing test. However, in the volatile metabolites test, none of the isolates achieved
an inhibitory effect. The analysis of non-volatile metabolites showed that the isolate of T.
asperelloides TR-356 can inhibit the mycelial growth of F. oxysporum without the need for
direct contact between the hyphae. The enzymatic tests indicated that the isolates of
Trichoderma spp., when in the presence of macerated mycelia of the phytopathogen F.
oxysporum, showed hydrolytic activities of important compounds present in the cell wall of the
host, with emphasis in this action on the isolates T. asperelloides TR-356 and Trichoderma spp.
2. With the results obtained, it was possible to conclude that the isolates T. asperelloides TR-
356 and Trichoderma spp. 2 were the most effective in antagonizing the phytopathogen F.
oxysporum, making them potential BCAs.
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