Ibrahim KONATE, Annick KOULIBALY, Ibourahema COULIBALY, El Bekkay BERRAHO
Abstract: We aim use in this study, endophytic bacteria isolated from inside the roots (IRC) and epicotyls (IEC) of carob (Ceratonia siliqua L.) plants collected from different Moroccan regions and previously screened by Rep-PCR. 30 IRC and 4 IEC strains selected on the basis of Rep-PCR representative groups and 8 carob symbiotic bacteria (RCM) were tested for their solubilizing activities and antibiotic resistance and analyzed by PCR-RLFP technique. 70 % and 50 % of carob associative bacteria and RCM strains respectively were solubilizing phosphate in culture media with P solubilization index (SI) ranged from 1, 63 to 2, 13 for IRC and IEC and from 1, 25 to 1, 5 for RCM. Amplified ribosomal DNA analysis (ARDRA) of the isolates based on cleavage with four restriction enzymes yielded 25 genotypes with IRC and 3 and 5 differents profiles respectively with IEC and RCM. Dendrogram based on upon UPGMA analysis of ARDRA patterns showed a wide genetic diversity and divided the strains into six clusters at 50 % of similarity level. Two clusters revealed relatedness with the rhizobial reference strains used and four others clusters which contain mainly associative endophytic bacteria were more heterogeneous and very distinct from all the other strains.
Keywords: Associative bacteria, carob Ceratinia siliqua L, Phosphate solubilization, ARDRA