The present study included isolation of Sinorhizobium meliloti bacteria from the root nodules of Alfalfa plants, Transformation process was conducted by conjugation with transformed bacteria Agrobacterium tumefaciens. The results showed the efficiency of the process, where the antibiotic tests acquire two genetic labels, resistance to chloramphenicol and rifampicin on the conjugated strain, proved that Ti plasmid (Tumorinducing Plasmid) transferred from the A. tumefaciens as well as that the conjugated strain produces melanin pigment. For more assurance, Alfalfa plants were inoculated with the conjugated strain, and the results showed the success of conjugation via crown gall formation on stem which formed by Ti plasmid in addition to root nodules in same plant. These results indicate the capability of performing conjugation technique between different species of Rhizobiaeceae to acquire new isolates carrying beneficial characteristics that are able to be transfer to plants and produce a new desired genetic transformed plants.

Samples of the root nodules were collected to isolate different species of the genus Rhizobium from several leguminous plants; Trigonella  foenum-graecum, Medicago sativa, Lens culinaris, Vigna mungo, Vicia faba,  Phaseolus vulgaris, and Cicer arietinum, and based on their morphological, cultural, and biochemical characteristics, in addition to the identification of each isolate at the species level by amplified polymerase chain reaction (PCR) and using the sequencing of the nitrogenous bases of the 16S rRNA gene, it was identified as Sinrhizobium meliloti, Sinrhizobium meliloti, Bradyrhizobium elkanii, Rhizobium leguminosarium biovar viciae, Rhizobium leguminosarium biovar phaseoli and Mesorhizobium cicero, respectively, (with the exception of bacteria isolated from Lens culinaris) it showed an agreement with the GenBank isolates with percentages ranging between (96-98) percent, as well as drawing the phylogenetic tree to determine the extent of evolution between these isolates and their convergence in the original with the international standard isolates.