Betterment of biological nitrogen fixation in snap bean under Mediterranean semi-arid conditions

A greenhouse experiment was implemented to evaluate the influence of Rhizobia strain inoculation, on growth, nitrogen purport, nodulation and enzymatic activities of common bean (Phaseolus vulgaris L.). The factors studied are two varieties of beans and three strains of Rhizobium. The results indicate that the two indigenous strains are low effective than the international strain (tropici CIAT 899), which present the best results for all parameters analyzed whatever the variety. A significant interaction was detected between varieties and rhizobia for the number and dry weight nodule (p <= 0.05). In fact, Plants inoculated with R. tropici CIAT 899 showed the highest total biomass by fixing the most atmospheric nitrogen. The enzyme test linked to the nitrogen assimilation process was realized in leaves of bean. It was revealed that the activities of GOGAT and GS were higher than GDH and MDH activities. R. Ciat 899 inoculation showed the up mostest values in all enzymatic activity compared to the control and native Rhizobium. However, our study pointed out the high affinity between Rhizobium tropici and the Italian variety "Garrafel Enana".