Diversity and cross inoculation abilities amongrhizobia isolated from different guar (C yamobsistetragonoloba (L.) Taub.) lines

Abstract

/\ hstract Ten R/1/zu/uiini lSUlillCs were isolated Iroin the root nodules olltcn guar lines. The isolates were authenticated each with ills respective host (line) of isolation. Cross-inoculation experiments revealed a wide range in the degree of line-isolate efliciency. The majority of guar lilies benefited from R/7/3!)/HIIIH inoculation. This was rellected in the high shoot dry weight and nitrogen content produced by the inoculated plants as compared to their respective non-inoculated controls. l\/licroscopical and biochemical characterization showed that all tested isolates were last growing, inicroaerophilic, acid producing, catalase and oxidase positive, they donlt absorb congo red, and were unable to grow on Glucose Pepton Agar (GPA). The isolates did not utilize citrate or ornithine and were also unable to produce HZS, lndole_ Acetoin or 3- ketolactose. All isolates were able to utilize most olthe tested carbohydrates as sole carbon sources and were also able to tolerate high salinity level (up to I92 gill), /\ntibiotic sensitivity tests showed a wide range oi‘ variations among the isolates. However, all tested isolates were lound to be resistant to Tetracycline and Ampicilin. Serologically, all isolates cross- agglutinated with each other indicating close serological alillinities among them. Summing up _ cluster analysis have separated the isolates into four groups that have included the following isolates: l- Group l: isolates /\22_ B4_ E51 l'l 5 and lll5. 2- Group ll: isolates D30 and ll2. 3- Group lll: isolate G7. 4- Group V: isolates C33 and lll5. i\ l Z