The effect of drought stress on the efficiency of rhizobial bacteria (Rhizobium leguminosarum) symbiotic with faba bean (Phaseoulus vulgaris) Barkat variety

In order to investigate the effect of drought stress on some growth parameters and nodulation index, the symbiotic efficiency of rhizobial isolates an experiment in controlled greenhouse conditions in the form of a completely randomized design with 21 rhizobial isolates, a negative control treatment (without rhizobial bacteria) and a control treatment Positive (no bacteria with nitrogen fertilizer at the rate of 70 mg/kg from urea source) and 3 repetitions were done in 2013. Different levels of drought stress including drought in two levels S0 (100% of field capacity (control or no drought stress)), S3 (55% of field capacity (severe stress)), which by adding different concentrations of zero and 310 grams per liter of polyethylene glycol 6000 (PEG) was applied to the nutrient solution after one week of seedling germination. The results of statistical analyzes showed that drought stress had a significant reduction effect on shoot dry weight, shoot water content, nitrogen content, symbiotic efficiency of rhizobial isolates and nodulation index.