title: Native Killer Yeasts as Biocontrol Agents of Postharvest Fungal Diseases in Lemons.
abstract: Economic losses caused by postharvest diseases represent one of the main problems of the citrus industry worldwide. The major diseases affecting citrus are the "green mold" and "blue mold", caused by Penicillium digitatum and P. italicum, respectively. To control them, synthetic fungicides are the most commonly used method. However, often the emergence of resistant strains occurs and their use is becoming more restricted because of toxic effects and environmental pollution they generate, combined with trade barriers to international markets. The aim of this work was to isolate indigenous killer yeasts with antagonistic activity against fungal postharvest diseases in lemons, and to determine their control efficiency in in vitro and in vivo assays. Among 437 yeast isolates, 8.5% show to have a killer phenotype. According to molecular identification, based on the 26S rDNA D1/D2 domain sequences analysis, strains were identified belonging to the genera Saccharomyces, Wickerhamomyces, Kazachstania, Pichia, Candida and Clavispora. Killers were challenged with pathogenic molds and strains that caused the maximum in vitro inhibition of P. digitatum were selected for in vivo assays. Two strains of Pichia and one strain of Wickerhamomyces depicted a significant protection (p <0.05) from decay by P. digitatum in assays using wounded lemons. Thus, the native killer yeasts studied in this work showed to be an effective alternative for the biocontrol of postharvest fungal infections of lemons and could be promising agents for the development of commercial products for the biological control industry.
authors: Planta Piloto de Procesos Industriales Microbiológicos - Consejo Nacional de Investigaciones Científicas y Técnicas, Tucumán, Argentina.
authors: María Florencia
authors: MF
authors: Perez
authors: Planta Piloto de Procesos Industriales Microbiológicos - Consejo Nacional de Investigaciones Científicas y Técnicas, Tucumán, Argentina.
authors: Luciana
authors: L
authors: Contreras
authors: Planta Piloto de Procesos Industriales Microbiológicos - Consejo Nacional de Investigaciones Científicas y Técnicas, Tucumán, Argentina.
authors: Nydia Mercedes
authors: NM
authors: Garnica
authors: Instituto de Microbiología, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán. Ayacucho 471 (4000), Tucumán, Argentina.
authors: María Verónica
authors: MV
authors: Fernández-Zenoff
authors: Planta Piloto de Procesos Industriales Microbiológicos - Consejo Nacional de Investigaciones Científicas y Técnicas, Tucumán, Argentina.
authors: María Eugenia
authors: ME
authors: Farías
authors: Laboratorio de Desarrollo e Investigación, SA San Miguel, Lavalle 4001, T4000BAB, San Miguel de Tucumán, Argentina.
authors: Milena
authors: M
authors: Sepulveda
authors: Laboratorio de Desarrollo e Investigación, SA San Miguel, Lavalle 4001, T4000BAB, San Miguel de Tucumán, Argentina.
authors: Jacqueline
authors: J
authors: Ramallo
authors: Planta Piloto de Procesos Industriales Microbiológicos - Consejo Nacional de Investigaciones Científicas y Técnicas, Tucumán, Argentina.|Instituto de Microbiología, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán. Ayacucho 471 (4000), Tucumán, Argentina.
authors: Julián Rafael
authors: JR
authors: Dib
mesh_terms: D002957:Citrus / Q000254:growth & development / Q000382:microbiology*; D010407:Penicillium / Q000502:physiology*; D010572:Pest Control, Biological / Q000379:methods*; D010641:Phenotype; D010935:Plant Diseases / Q000382:microbiology*; D010957:Plasmids / Q000235:genetics; D015003:Yeasts / Q000235:genetics / Q000502:physiology*