Biosupression grape fungal pathogens in integrated management of fungal diseases

NALLY M.C; PESCE V.M.; MUÑOZ M.A.; RADICETTI D.S.; TORO M.E.; CASTELLANOS DE FIGUEROA L.I.; VAZQUEZ F.

San Juan

Otro; 2da Reunión Conjunta de las Sociedades de Biología de la República Argentina; 2011

Introduction: San Juan province is the main producer and exporter of Argentine table grapes and in 2010 export totaled about 51,776 metric tons. However, when fruit is exported to foreign countries prolonged periods of postharvest disease control are required. These pathogens can be controlled on grapes with pre and postharvest fungicidal treatments. The emergence of fungicide resistance and increasing consumer demands for reduction in residues on fruit emphasize the need for alternative disease control strategies. Biological control of postharvest diseases of fruits and vegetables by antagonistic yeasts seems promising in replacing or reducing the use of synthetic fungicides. Objective: Evaluated of population dynamic of biocontrol yeasts in grapes. Materials and Methods: 1- Population profiles of yeasts: The ability of biocontrol yeasts to survive and multiply in grape wounds was determined as follows: grape berries were rinsed with water, wounded, inoculated with 20 μl of a washed cell suspension (106 cells/ml), placed on plastic trays (80% RH) and incubated at 25°C. The grape sample was placed in 10 ml of sterile 0.05 M phosphate buffer, pH 7.0. Then, dilution series in sterile distilled water were spread onto YEPD-Agar and incubated at 25ºC. Colony counts were carried out after 3 days. Results: Of the 59 biocontrol yeasts that were inoculated in wounds of grapes at 25ºC, 24 yeasts significantly increased their population in grape Red globe. Conclusions: Many yeast species are able to colonize surfaces for long periods of time, characteristics that are relevant in the selection of biocontrol agents.