Native yeasts as biocontrol agents against gray mold in blueberries

FLORENCIA ISABEL CHACÓN; PEDRO EUGENIO SINELI; MICAELA ÁLVAREZ; MARIANA ANDREA DÍAZ; MARTINA MARÍA PEREYRA; FLAVIA INÉS MANSILLA; ANA POEHLEIN ; ROLF DANIEL; JULIÁN RAFAEL DIB

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

Botrytis cinerea, causal agent of gray mold disease, is one of the main fungal pathogensaffecting blueberry production worldwide. Traditional strategies aiming at prevention ofpostharvest fungal decay include the use synthetic fungicides, which entails a number ofdisadvantages such as environmental and human negative impacts, the emergence ofresistant phytopathogenic strains, and trade barriers. To date, there are no known efficientalternatives for biological control in blueberries, based on the use of microorganismsadapted to local conditions. Thus, the aim of this work was to isolate and identify nativeyeasts with biocontrol activity against gray mold in blueberries. Native yeasts from theblueberry microbiome were isolated from an organic crop in Tucumán, Argentina, andidentified based on the 26S rDNA D1/D2 domain sequence analysis. Antagonistic activitiesagainst B. cinerea were studied in in vitro and in vivo assays. Furthermore, the yeastsability to produce volatile organic compounds inhibiting the fungus mycelial growth werealso 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 Rhizosphaeramacrospora, depicted the most significant in vivo protection efficiency (83.88%). Moreover,LMEA8 was able to produce volatile organic compounds which inhibited the growth of thefungus by 82.15%. Therefore, R. macrospora LMEA8 proved to be a suitable candidate forthe development of a novel biocontrol agent for blueberries and adapted to the local fruitsconditions.