Screening of Indigenous Microorganisms as Potential Biofertilisers for Periurban Horticulture Areas

In Buenos Aires periurban area, horticultural practices are one of the most important activities. Pesticides and fertilisers are used without any control to cover the farmers´ needs, obtaining high crop yields at short terms and modifying soil ecosystem in the long term. The aim of this work was to isolate indigenous strains from periurban horticultural units with pesticide degrading capacity and to evaluate their plant growth-promoting properties in order to design biofertilisers to be applied in the restoration of these exploited soils. After the screening, eight strains were isolated and identified. They showed not only the capacity to produce indole-3- acetic acid, to fix nitrogen, to secrete siderophores and to solubilise calcium phosphate but also tolerated the mixture of pesticides usually used for horticultural practices. By their behaviour in mixed cultures and plant growth-promoting properties, these autochthonous isolates represent a promising alternative as biofertilisers according to soil type and activity.Fil: Querejeta, Giselle Andrea. Universidad Nacional de General Sarmiento. Instituto de Ciencias. Área de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rossi, Leticia. Universidad Nacional de General Sarmiento. Instituto de Ciencias. Área de Química; ArgentinaFil: Monroy, Andrea Micaela. Universidad Nacional de General Sarmiento. Instituto de Ciencias. Área de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Raiger Iustman, Laura Judith. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Vullo, Diana Lia. Universidad Nacional de General Sarmiento. Instituto de Ciencias. Área de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Screening of Indigenous Microorganisms as Potential Biofertilisers for Periurban Horticulture Areas

In Buenos Aires periurban area, horticultural practices are one of the most important activities. Pesticides and fertilisers are used without any control to cover the farmers’ needs, obtaining high crop yields at short terms and modifying soil ecosystem in the long term. The aim of this work was to isolate indigenous strains from periurban horticultural units with pesticide degrading capacity and to evaluate their plant growth-promoting properties in order to design biofertilisers to be applied in the restoration of these exploited soils. After the screening, eight strains were isolated and identified. They showed not only the capacity to produce indole-3- acetic acid, to fix nitrogen, to secrete siderophores and to solubilise calcium phosphate but also tolerated the mixture of pesticides usually used for horticultural practices. By their behaviour in mixed cultures and plant growth-promoting properties, these autochthonous isolates represent a promising alternative as biofertilisers according to soil type and activity

Environmental Fate of Trifluralin, Procymidone, and Chlorpyrifos in Small Horticultural Production Units in Argentina

Pesticide biodegradation was studied in soil samples of a representative small periurban production unit (Moreno District, Argentina). The mean periods required for the 50% dissipation of chlorpyrifos (16 days±1 day), procymidone (3.7 days±0.6 day), and trifluralin (3.6 days±0.6 day) were significantly lower than those measured for reference soil samples of a close location, using doses similar to the manufacturer?s recommendation. A preliminary screening scheme for pesticide-degrading bacteria on horticultural soil allowed the isolation of nine culturable bacterial strains, eight of which belonged to Pseudomonas genus. In order to consider the influence of the variability of soil properties on the biodegradation results, humidity, organic matter, conductivity, pH, water retention volume, density, respiration, and total phosphorous content were studied for different soil samples, finding no significant differences in the performed analysis. Overall, although the horticultural activity alters the natural soil, pesticide contamination effects could be reversed by the autochthonous microbial community.Fil: Querejeta, Giselle Andrea. Universidad Nacional de General Sarmiento. Instituto de Ciencias. Área de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ramos, Laura Mabel. Universidad Nacional de General Sarmiento. Instituto de Ciencias. Área de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Hughes, Enrique Alejandro. Universidad Nacional de General Sarmiento. Instituto de Ciencias. Área de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vullo, Diana Lia. Universidad Nacional de General Sarmiento. Instituto de Ciencias. Área de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zalts, Anita. Universidad Nacional de General Sarmiento. Instituto de Ciencias. Área de Química; ArgentinaFil: Montserrat, Javier Marcelo. Universidad Nacional de General Sarmiento. Instituto de Ciencias. Área de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin

Infection with Micromonospora strain SB3 promotes in vitro growth of Lolium multiflorum plantlets

Cattle breeding is an important economical activity in Argentina, highly dependent on grass production. In the last decades, grasslands zones were reduced and confined to less productive lands due to the advance of agronomical cultures. Therefore, it is important to develop new strategies to improve forage production. New eco-friendly trends in plant growth promotion include the use of microbial endophytes, but the in vitro studies of plant-bioinoculant interactions is limited by the scarce current technological development. In this work, we use a micropropagation protocol for Lolium multiflorum, developed in a previous work, to study the effect of bacterization with actinobacterial endophytes, isolated from Argentine native grasses, on the growth of L. multiflorum in vitro plantlets. To achieve this objective, L. multiflorum plantlets were inoculated with three Micromonospora strains (SB3, TW2.1 and TW2.2). The results obtained showed that the effect of actinobacterial inoculation depends on the Micromonospora strain used. The inoculation with SB3 promoted plant growth, increasing plant biomass, root length and the rate of plantlets ready to be acclimatized after 4 weeks of in vitro culture. Strain TW2.1 did not show, statistically, differences compared to control treatments, while TW2.2 inhibited plant growth, decreasing plant biomass, root length and the rate of plants ready to acclimatize. Our results showed that Micromonospora strain SB3 could be a good candidate to use in breeding programs for L. multiflorum and other grasses to increase their yield.Fil: Della Mónica, Ivana Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: Novas, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: Iannone, Leopoldo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: Querejeta, Giselle Andrea. Universidad Nacional de General Sarmiento. Instituto de Ciencias. Área de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scervino, Jose Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Pitta Alvarez, Sandra Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Cultivo Experimental de Microalgas; ArgentinaFil: Regalado González, Jose Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Cultivo Experimental de Microalgas; Argentin