Isolation and biochemical characterization rhizosphere bacteria as promoters of plant growth

JESUS LAMI; COSTA GUTIERREZ SB; CARAM DI SANTOS, CAROLINA; FERNANDA POMARES; VINCENT P.A; ESPINOSA-URGEL M; DE CRISTÓBAL RICARDO E

La Falda Córdoba

Workshop; pgpr Latinoamérica 2014; 2014

Universidad Nacional de Río Cuarto

Introduction On the scale of human and ecological time, the soil is a nonrenewable resource, so conservation is a critical factor to ensure the growing demands for food in the world. Much of the problems faced by humanity are due to degradation and loss of arable land and the loss of organic carbon content, lower structural stability, the decrease in soil biological activity, increased risk of extent of erosion and salination. Faced with these problems, emerged among many others, studies in which rhizosphere bacteria that stimulate the growth of plants as bioinoculants implemented. Objective Isolate and identify potential plant growth promoting rhizobacteria saline soils and biochemically characterize them as such. Materials and Methods Root samples from Argentine Salinas, Salinas Grandes de Santiago del Estero y Antinaco Valley of La Rioja. The isolation was based on differences in the morphology of their colonies. The isolates were identified by sequencing the 16S gene and characterization were determined the ability to solubilize inorganic phosphate by growth on solid with tricalcium phosphate medium (NBRIP supplemented), production of total indoles determined by the colorimetric reaction with the reagent Salkowsky, and resistance to 1.2 M NaCl in solid LB medium. Was used as positive control Pseudomonas putida. Results 25 strains were isolated in total. In characterization was obtained 20 strains solubilized phosphate solubilization efficiency being 3.33 to 4.02% between the highest rates of dissolution, compared to the control 2.92%. Are 14 strains producing siderophores, which strain had an efficiency of 350%, and greater than 217% control. Other ranges near that of the control. Total production in strains producing indoles from 0.17 to 24 ug / mL. Finally, nine strains grow optimally with NaCl (good mass and isolated colonies), 8 only grow to ground and the other did not grow. Conclusion Potentially promoting plant growth rhizosphere strains were isolated. Strains 2, 17S, 22S, 33S, 34S being the Salinas Grandes and 41S Antinaco Valley, are those with increased activity in all biochemical tests and resistance to NaCl. Áreas temáticas propuestas: Biotecnología (4) y Aplicaciones agronómicas (5)