Seleção de isolados bacterianos no controle de Colletotrichum musae IN VITRO

Abstract

Banana (Musa spp.) is an economically important crop whose anthracnose, caused by Colletotrichum musae, is mainly treated using chemical fungicides. Plant growth-promoting bacteria (PGPBs) have several antagonistic mechanisms against phytopathogens and can be used as biological control. However, there is still a lack of studies on its applications in post-harvest treatment. Given this, the objective was to select bacterial isolates to control C. musae in vitro. In the in vitro test, bacterial isolates from the bacteriotheca collection of the Phytopathology Laboratory of the State University of Montes Claros were subjected to antibiosis tests by pairing, and volatile organic compounds by overlap, against C. musae. And subsequently, the fungal colony area, germination and sporulation of C. musae were evaluated. The experiments were conducted in a completely randomized design with 81 treatments (80 bacterial isolates + 1 control), each treatment consisting of three replications. The data were subjected to analysis of variance using the Scott-Knott test (p<0.05) and multivariate analysis. Isolates RZ65 (B. amyloquefaciens), RZ44 (B. pumilus) and RZ41 (B. amyloquefaciens) by the antibiosis test, and isolates B11.16 (B. pumilus) and RZ50 (B. pumilus) by the organic compounds test volatiles, reduced the colony area, number of germinated spores and number of spores produced of C. musae in vitro. Bacillus sp. (B1.18), B. tequilensis (B15.7), B. methylotrophicus (B3.2), B. amyloquefaciens (RZ41), B. pumilus (RZ44) and B. amyloquefaciens (RZ65) were the most promising bacteria in control of C. musae in vitro, by analysis of main components using multivariate. The bacterial isolates studied have the potential to control C. musae in vitro.