CONICET | Buscador de Institutos y Recursos Humanos

Argentina is the worlds leading lemon producer and industrialist and the second-largest exporter of this fruit. More than 70% of the industry's production is destined for the elaboration of concentrated juice, dehydrated peels, and essential oil; the remaining 30% is marketed as fresh fruit. Tucumán province, for its climate and soil properties, has positioned itself as the citrus area par excellence, contributing over 70% of lemons. After harvest, lemons become susceptible to the attack of saprophytic pathogens or parasites, mainly of fungi origin, due to their high content of water and nutrients, and because they have lost most of the intrinsic resistance that protects them during their development in the tree. It is of great importance to control the development of these decays, and the use of chemical fungicides has been the best option due to their low cost, easy application, and great effectiveness. However, there are some drawbacks related to the indiscriminate use of these products since they can generate the appearance of fungi resistance. In recent years the use of yeasts, fungi, and bacteria as biological controllers has been a promising alternative for the control of post-harvest diseases. Several studies have been reported regarding the control of post-harvest diseases through the use of yeasts. To carry out the research, we have been working on native yeasts with killer phenotypes isolation and characterization from different citrus plants from a Tucuman. 437 yeasts strains were isolated, of which 8.5% presents the killer phenotype. These were identified and used in in vitro tests to prove their inhibitory effect against P. digitatum, P. italicum and P. citri. Those yeasts that showed the best antagonistic effects against phytopathogens were then tested in in vivo assays using lemons. As a result of this investigation, yeast capable of controlling the development of fungal infections in lemons with efficiencies above 90% were found, providing us with a potential alternative for the development of a commercial biological product that is even compatible with the organic production of fruits.