Seleção de leveduras em associação com substâncias GRAS (Generally recognized as safe) para o controle da antracnose (Colletotrichum gloeosporioides) em manga pós-colheita

Abstract

Controlling post-harvest diseases in tropical fruits plays an important aspect in preventing losses during storage and marketing. The indiscriminate use of chemical fungicides has had adverse consequences for both human health and the environment. Given this scenario, the present study aimed to propose a strategy for controlling the phytopathogen Colletotrichum gloeosporioides, the causal agent of anthracnose, exploring the potential for inhibiting this pathogen through the use of Amazonian yeasts associated with GRAS substances, both in the classical and integrated control approach. , seeking to evaluate the reduction in the incidence and severity of pathology in post-harvest mangoes. Yeasts were selected from three Amazonian fruits. A total of 300 isolates were reactivated, among these, three yeasts (LB29, LT76, LP101) and the substance sodium carbonate were chosen as possible controlling agents. The choice of antagonistic biocontrol yeasts was based on the evaluation of growth tests at different temperatures, verification of the production of pectinase and cellulase enzymes and observation of the production of antagonistic substances against the phytopathogen. In in vivo tests of classical biological control, strains LB29 and LT76 were able to reduce the incidence of the disease caused by C. gloeosporioides by around 20 and 30% and 69 and 58% of severity, respectively, while in the integrated control the substance GRAS (sodium carbonate) together with strains LB29 and LT76 decreased incidence by 50 and 50% and severity by 69 and 58%, respectively. On the other hand, sodium carbonate alone reduced the incidence by 90% and the severity by 90%. After the experiment, the effectiveness of yeast associated with the GRAS substance in reducing a little more than 50% of the severity of the disease was verified, as well as just the GRAS substance significantly reducing the incidence and severity of the disease, through classical and integrated control. . This shows that the selection of these yeasts and the GRAS substance can be a promising strategy for controlling anthracnose disease in mango.