In vitro PGPR properties and osmotic tolerance of different Azospirillum native strains and their effects on growth of maize under drought stress

Osmotic variations in the soil can affect bacterial growth diminishing the number of inoculated bacteria. In a scenario of water deficit having tolerant bacteria would be beneficial to achieve a better response of the plant to stress. Thus, selection of more resistant bacteria could be useful to design new inoculants to be used in arid zones. In this sense, a group of Azospirillum isolates deposited in INTA collection was characterized in order to select strains tolerant to osmotic stress. The results obtained demonstrated that Az19 strain has similar in vitro PGPR characteristics to Az39, the most used strain in Argentina for inoculants industries, with the advantage of a better tolerance to osmotic and salt stress. Inoculation of maize plants with this strain resulted in a better response against water deficit compared to Az39 strain, encouraging us to further study the behavior of this strain in greenhouse and field trials in view of developing new inoculants suitable for areas with water deficit.

Inst. de Microbiología y Zoología Agrícola IMyZA

Fil: Garcia, Julia Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; Argentina

Fil: Maroniche, Guillermo Andrés. Unidad Integrada Balcarce-Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias-Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Fil: Creus, Cecilia. Unidad Integrada Balcarce-Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias-Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina

Fil: Suárez-Rodríguez, Ramón. Universidad Autónoma del Estado de Morelos. Centro de Investigación en Biotecnología; México

Fil: Ramirez-Trujillo, José Augusto. Universidad Autónoma del Estado de Morelos. Centro de Investigación en Biotecnología; México

Fil: Groppa, María D. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Consejo Nacional de lnvestigaciones Cientificas y Tecnicas. Instituto de Química y Fisicoquímica Biológicas; Argentina