Characterization of phosphate solubilizing bacteria isolated from rizosphere of Lotus tenuis

CASTAGNO, LUIS NAZARENO, ESTRELLA, MARÍA JULIA, GRASSANO, ALICIA Y RUIZ, OSCAR ADOLFO

Estoril (Portugal)

Congreso; I Congreso Luso Español de Fijación de Nitrógeno y XII Reunión Nacional de Fijación de Nitrógeno (España); 2008

Sociedad Española de Fijación de Nitrógeno

In this study, phosphate solubilizing bacteria were isolated from soil samples of the rizosphere of Lotus tenuis (Latitude 35º 30´ S. Longitude 58º 30´ W). NBRIP culture medium was used for the selection (Nautiyal C. S.; 1999). The molecular identification of the isolates was performed by the BOX-PCR technique. In order to characterize them and establish a correlation between parameters, kinetic of phosphate solubilization and pH evolution were evaluated. Two isolates that showed the highest phosphate solubilization activity were selected and inoculated onto L. tenuis plants in vitro in semisolid Evans medium (Evans C.G.T.; 1970). Soil stress conditions were simulated replacing phosphate source with Ca3(PO4)2 and varying  P/N rate, as well as pH. Inoculation with phosphate solubilizing bacteria significantly enhanced growth of L. tenuis plants, as compared with non-inoculated controls. This suggests that these bacteria would improve L. tenuis development in critical stages like implantation.