NUMERICAL TAXONOMY AS A TOOL FOR THE CLASSIFICATION OF ROOT-NODULE BACTERIA

The taxonomy of root-nodule bacteria has been complicated by the fact that these bacteria display two very different forms of life - the symbiotic stage with the plant and the free-living life in soil. Application of numerical methods to taxonomic data from experiments with these bacteria has, however, in many cases been successful in the sense that the groups obtained have been confirmed when using other, mainly genetic, methods. When anomalies occurred, those could be attributed to lack of knowlege of the structure and dynamics of the rhizobial genomes, questions that are possible to address with modem molecular methods. When designating new species, a polyphasic approach is recommended.