Native yeasts as biocontrol agents against gray mold in blueberries

CHACÓN FLORENCIA ISABEL; SINELI, PEDRO EUGENIO; ALVAREZ, MICAELA; DIAZ, MARIANA ANDREA; PEREYRA, MARTINA MARIA; MANSILLA, FLAVIA IVANA; POEHLEIN, ANJA; DANIEL, ROLF; DIB, JULIÁN RAFAEL

Conferencia; The 1st IBA-International Conference on Challenges in Sustainable Utilization and Management of Bioresources, 2022 (IBA-SUMBio22); 2022

Botrytis cinerea, causal agent of gray mold disease, is one of the main fungal pathogens affecting blueberry production worldwide. Traditional strategies aiming at prevention of postharvest fungal decay include the use synthetic fungicides, which entails a number of disadvantages such as environmental and human negative impacts, the emergence of resistant phytopathogenic strains, and trade barriers. To date, there are no known efficient alternatives for biological control in blueberries, based on the use of microorganisms adapted to local conditions. Thus, the aim of this work was to isolate and identify native yeasts with biocontrol activity against gray mold in blueberries. Native yeasts from the blueberry microbiome were isolated from an organic crop in Tucumán, Argentina, and identified based on the 26S rDNA D1/D2 domain sequence analysis. Antagonistic activities against B. cinerea were studied in in vitro and in vivo assays. Furthermore, the yeasts ability to produce volatile organic compounds inhibiting the fungus mycelial growth were also evaluated. 29 yeast strains were isolated and attributed to nine different genera: Metschnikowia, Hanseniaspora, Clavispora, Aotearoamyces, Rhizosphaera, Rhodotorula, Capturomyces, Moesziomyces and Naganishia. Strain LMEA8 identified as Rhizosphaera macrospora, depicted the most significant in vivo protection efficiency (83.88%). Moreover, LMEA8 was able to produce volatile organic compounds which inhibited the growth of the fungus by 82.15%. Therefore, R. macrospora LMEA8 proved to be a suitable candidate for the development of a novel biocontrol agent for blueberries and adapted to the local fruits conditions.