Effect of some environmental factors on Rhizobium and Bradyrhizobium strains.

Effects of different abiotic factors (acidity, salinity, nitrate and temperature) on growth rate of root-nodule bacteria (Rhizobium and Bradyrhizobium) strains were investigated in vitro. Strains isolated from Vicia faba L., Coronilla varia L. and Lupinus albus L. exhibited a large variation in tolerance of the above-mentioned factors. These bacteria should be screened under stimulated conditions for enhanced survival before selection to be used for commercial inoculant production. Linear correlation matrix data were useful to find the appropriate concentrations for the selection of the tolerant strains.