Effect of phosphorous solubilizing bacteria on the rhizobia – legume simbiosis

 

Susana B. Rosas*, Marisa Rovera, Javier Andrés, Néstor S. Correa

 

Lab Fisiologia Vegetal. Fac Cs Exactas Fco Qcas y Naturales. Campus Universitario 5800 Río Cuarto (Cba) ARGENTINA

*srosas@exa.unrc.edu.ar

 

 

Alfalfa and soybean are  the leguminous most important in the agricultural system of the semi-arid region of Argentina. Since in this region the available phosphorus distribution (Pd) is not uniform, the possible action of phosphorus solubilizing bacteria on the leguminous – rhizobia simbiosis is studied. The strains  used were Sinorhizobium meliloti 3DOh13 , excellent solubilizer of Fe and P for alfalfa, Bradyrhizobium japonicum TIIIB for soybean and two strains of Pseudomonas putida (Sp21 and Sp22) solubilizers of P for the treatments of growth promotion through an improvement in the nodulation and nitrogen biological fixing. The rhizobia strains assayed  are capable of coexisting with Pseudomonas, being observed meaningful differences  in percentage of nodulation and air portion in soybean co-inoculated.