Characterization and PGPR activity of peanut native microsimbionts

BRESSANO, M.; MORENO, D.; TAURIAN, T.; CASTRO, S.; FABRA, A.

Villa General Belgrano, Córdoba, Argentina

Jornada; XIV Jornadas Científicas de la Sociedad de Biología de Córdoba; 2003

Sociedad de Biología de Córdoba

The increase in the yield of some leguminous plants inoculated with selected rhizobia strains has been associated with the rhizobia ability to act as plant growth promoting rhizobacteria (PGPR). Several researches show that rhizobacteria may also exhibit growth promoting effects on not leguminous plants. Like other PGPR, rhizobia produce siderophores, cyanides and show antagonistic activity against phytopathogen fungi. They are also able to solubilize organic and inorganic phosphate. Because of their adaptation to the ecological conditions from a local soil, the native strains are preferentially used to inoculate a determinate area. Thus, the genotypic characterization, the symbiotic performance determination as well as the identification of strains with other PGPR properties is recommended. Methods: tolerance to adverse conditions, phosphate solubilization, siderophores production and antifungical activity, ERIC-PCR. Three of the six isolates studied were fast growers. No relationship was found between growth rate and tolerance to adverse conditions. Fifty percent of the isolates was able to solubilize inorganic phosphate or produce siderophores and 67% showed antagonism against plant pathogenic fungi. Isolate NLH 32 showed all the PGPR activities tested. The fingerprint profiles obtained with primers E1/E2 showed a great heterogeneity between the isolates.