Abstract
The aim of this work was to characterize and identify the root-nodule bacteria isolated from broad bean (Vicia faba) plants grow in the cultivated lands of Beni-Suef Governorate, Egypt. The cultural, biochemical, and molecular characteristics were determined. Two isolates were able to grow at 6% NaCI. Four isolates showed catalase, urease and gelatinase activity, two isolates have ability for ammonia production, and only one isolate that could produce Siderophore and HCN. Three isolates were capable of solubilizing phosphate. In the presence of tryptophan, the four isolates (RV1, RV2, RV3 and RV4) produced indole acetic acid (134, 90, 154 and 75 lag/ml), respectively, in the growth medium. All isolates were capable of inhibiting the growth of pathogenic fungal strains of Fusarium oxysporum and Rhizoctonia solani. The strains from V. faba had 99% identity with Rhizobium leguminosarum. Increasing of salt concentration decreased growth, nodulation and nitrogen fixation. The present study reveals that Rhizobium leguminosarum strains (RV1 and RV3) has a growth-promoting characters under salt stress and can be used as a biofertilizer inoculant beneficial for broad bean cultivation.