Antagonistic activity Trichoderma harzianum Rifai on the causal agent of rice blast (Pyricularia grisea Sacc.)

Abstract

With the objective to evaluate the antagonistic activity of T. harzianum (strain A-34) on the causal agent of rice blast (P. grisea), were developed several in vitro experiments. It was evaluated the biocontrol mechanisms such as competition through mounted the percent inhibition of radial growth of hyphae of P. grisea from 24 to 240 hours and the antagonistic capacity. In addition, was evaluated micoparasitism to inclination the observation of events Microscopy winding, penetration, vacuolization, lysis, and antibiosis by observing 24 hours a confrontation between the hyphae of the phytopathogenic fungus and biological control agent. It was obtained at 120 hours 100 % inhibition of micelial growth of causal agent, what corresponded with the degree 1 of antagonistic capacity (scale) and is recorded as a hyperparasitic action on P. grisea. It was evidenced an antibiotic effect of metabolites produced by T. harzianum (strain A-34) to 24 hours of confrontation, where there was time interaction between the hyphae of microorganisms with 14,3 % inhibition, also was evidence the micoparasitism events by penetration, vacuolization and lysis in the cells of phytopathogenic fungus. These results demonstrated the ability of T. harzianum (strain A-34) on causal agent of rice blast (P. grisea).

Keywords

• antibiosis
• competition
• micoparasitism