BACTERIAL ISOLATES FROM THE RHIZOSPHERE OF ALFALFA WITH PLANT GROWTH-PROMOTING RHIZOBACTERIA ACTIVITY

DESUQUE J.; COLLA C.; LUCERO C; AMBROSINO M; PAGLIERO F; CASTAGNO LN

Congreso; XLI Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2023

The present study aimed to select microorganisms from the rhizosphere of alfalfa with Plant Growth-Promoting activity (PGPM). Soil samples were collected from an alfalfa crop with no prior history of inoculation, located in a semi-arid area of La Pampa Province. Nine rhizospheric soil samples were obtained. Microorganism isolation was carried out using PCA for total Microorganism counting and a selective medium (NBRIP) for the initial screening of strains showing phosphate-solubilizing ability (first screening). Based on this, 142 isolates were selected, and subsequently, 36 isolates were further studied based on their phenotypic characteristics regarding other PGPM properties, such as the production of IAA (indole-3-acetic acid) and siderophores. In order to reduce redundancy, genetic characterization of the isolates was performed using ERIC-PCR, resulting in 23 different band-patterns.From the 23 selected isolates, it was found that 43% exhibited a high proportion of phosphate solubilization, 30% produced IAA at concentrations greater than 20 ug/mL, and 40% displayed a high capacity for siderophore production. The results obtained allow us to infer the possibility of generating regional bioformulations from native strains with activity in promoting the growth of alfalfa crops, serving as a key tool to enhance the specific agricultural system of the province. Therefore, it is essential to learn how to combine technologies to improve production benefits and preserve the agroecosystem.