CHARACTERIZATION OF RHIZOBIUM-ETLI AND OTHER RHIZOBIUM SPP THAT NODULATE PHASEOLUS-VULGARIS L IN AN AUSTRIAN SOIL

Phaseolus vulgaris L. (common bean) is nodulated by rhizobia present i n the fields around the Seibersdorf laboratory despite the fact that c ommon bean has not been grown for a long time. Using PCR analysis with repetitive primers, plasmid profiles, nifH profiles, PCR-RFLP analysi s of the 16S rRNA gene and of the 16S rRNA-23S rRNA intergenic spacer and the nodulation phenotype, two well-differentiating groups could be distinguished. One group showed high similarity to Rhizobium sp. R602 sp, isolated from common bean in France, while the other showed the sa me characteristics as X. etli. We detected little variation in the sym biotic regions but found higher diversity when using approaches target ing the whole genome. Many isolates obtained in this study might have diverged from a limited number of strains, therefore the Austrian isol ates showed high saprophytic and nodulation competence in that particu lar soil.