Evaluation of bacterial isolates from strawberry plants (Fragaria x ananassa Duch.) as biological control agents of Botrytis cinerea.

HIRSCH, MAILÉN; BURGES, PABLO; VILLARREAL, NATALIA M.; MARINA, MARÍA

Virtual

Congreso; SAIB-SAMIGE Joint Meeting 2021; 2021

Biological control of diseases in plants is the use ofliving organisms (known as biological control agents o BCAs) capable toeliminate or suppress the population of pathogens. BCAs can protect the plantvia different ways of action: space and nutrient competition with the pathogen,antimicrobial compounds production, biofilms formation, hydrolytic enzymes production,induction of defense responses in the host, among others. In this work, wefocus our study on bacteria isolated from strawberry plants as BCAs for Botrytiscinerea, a phytopathogen responsible for severe economic losses forproducers. First, 103 bacterial isolates (57 epiphytes and 46 endophytes) were obtainedfrom strawberry leaves and fruits. Then, they were evaluated for theirpotential antifungal activity by in vitro assays. The inhibition of B.cinereas growth by bacteria was tested in two ways: by the synthesis ofdiffusible and volatile compounds on plates with potato glucose agar (PGA)medium and by the emission of only volatile compounds using two plates placed"mouth-to-mouth" and sealed with parafilm. From the total, 82 strainsshowed significant differences for the inhibition assay by diffusible/volatilecompounds, and 71 for the inhibition by just volatile compounds. Based on theresults, 49 bacteria that showed statistical differences in both assays wereselected to continue their characterization. Carrying out BOX-PCR, we observedduplicate strains that presented the same molecular pattern of bands. As aresult, we have 47 non-redundant bacterial isolates with the capacity toinhibit the in vitro growth of B. cinerea. That is asignificant number of potential BCAs of that important phytopathogen tocontinue studying and identifying other mechanisms of action throughwhich they could exert biocontrol. Further studies will be performed to reducethe number of endophytes and epiphytes with the potential of being used as aneco-friendly alternative strategy to reduce the use of fungicides to controldiseases in strawberry plants.