Abstract
Four strains (FA37, FA38, FA39, and FA40 ) of Sinorhizobium meliloti were isolated from different agricultural areas of Ninaveh, Erbil and Duhok Governorates. Identification studies were conducted for these strains for their resistance to chloramphenicol, Erythromycin and production of cell surface molecules and their ability to grow in a Minimal Medium. Results showed that the four strains had the ability to resist both antibiotics, production of β(1→2) cyclic glucan molecules and growth in Minimal Medium. The study of symbiosis relation between the strains and Medicago sativa plant showed that the strain FA37 was the most successful isolate in constructing symbiosis relation indicated by the dry shoot group, which reached 45.7 mg. The strain was then selected for further experiments. Results revealed that the strain FA37 had high resistance against different concentrations of the herbicide Glyphosate, whereas the plant showed no resistance against the least concentration 10 µg/ml that the Rhizobium strains tolerated.