title: Selection of potential biological control of Exserohilum turcicum with epiphytic microorganisms from maize.
abstract: The aims of this study were to select microbial isolates from phyllosphere of maize and to examine their antagonistic activity against Exserohilum turcicum. Selection was performed through the ability of isolates to compete with the pathogen using an index of dominance and to affect growth parameters of E. turcicum. Most of the epiphytic populations obtained for the screening were bacteria. These isolates were found in the order of 6 log CFU/g of leaf fresh weight. According to similar morphological characteristics and staining, 44 out of 111 isolates obtained were selected for testing antagonistic effects. At water potential, ψ, -1.38MPa and -4.19MPa, three Bacillus isolates showed dominance at a distance (5/0) and a significant reduction of growth rate of the pathogen. Three Bacillus isolates only decreased the growth rate of E. turcicum at -1.38MPa. At -4.19MPa the growth rate decreased with three isolates of Pantoea and three Bacillus. In this study a negative and significant correlation was observed between the growth rate of E. turcicum and the dominance index in the interaction of the pathogen with some bacteria. These results show that with decreasing growth rate of the pathogen the dominance index of the interaction increases. Eleven potential biocontrol agents against E. turcicum were selected.
authors.affiliation: Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36 km 601 (X5806JRA), Río Cuarto, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
authors.forename: Melina
authors.initials: M
authors.lastname: Sartori
authors.affiliation: Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36 km 601 (X5806JRA), Río Cuarto, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
authors.forename: Andrea
authors.initials: A
authors.lastname: Nesci
authors.affiliation: INTA EEA Paraná, Ruta 11 km 12,5 (3101) Oro Verde, Paraná, Entre Ríos, Argentina.
authors.forename: Ángela
authors.initials: Á
authors.lastname: Formento
authors.affiliation: Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36 km 601 (X5806JRA), Río Cuarto, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina. Electronic address: metcheverry@exa.unrc.edu.ar.
authors.forename: Miriam
authors.initials: M
authors.lastname: Etcheverry
mesh_terms: D001203:Ascomycota; D001419:Bacteria; D061046:Biological Control Agents; D010935:Plant Diseases / Q000517:prevention & control*; D003313:Zea mays / Q000382:microbiology*
chemical_list: D061046:Biological Control Agents
keywords: Bacterias epifíticas; Biocontrol; Epiphytic bacteria; Exserohilum turcicum; Maize; Maíz