Phenotypic diversity of rhizobia has been studied by several methods,
particularly numerical analysis, enzyme pattern and serological study. Numerical analysis
employs a large range of biochemical and metabolic tests to differentiate among rhizobial
species. The results obtained from numerical analysis support the proposal of several novel
species of rhizobia. Rhizobial species vary in their enzymatic production and several
enzymes are found to be necessary for the symbiotic effectiveness. Serological techniques
are the most specific methods for identifying rhizobia based on natural marker
characteristics. Phenotypic characterization by serotyping has been used to explore
rhizobial populations in different geograpical origins. Rhizobia in different serogroups have
been found predominant among field populations.
Keywords: Antibody, Antigen, Biochemical characteristic, Enzyme pattern,
Numerical analysis, Phenotypic diversity, Serocluster, Serogroup, Serological
study, Rhizobia.
