RESEARCH TECHNIQUES FOR ESTIMATING PHENOTYPIC AND GENOTYPIC DIVERSITY OF ROOT-AND STEM-NODULE BACTERIA

Root- and stem-nodule bacteria symbiotically nodulate and fix nitrogen with certain leguminous plants. Members in 14 genera have been reported as nitrogen-fixing symbionts. Phenotypic and genotypic diversity of these symbiotic bacteria have been revealed, providing valuable information, through the use of methodologies for phylogenetic analyses. Numerical analysis based on phenotypic characteristics and techniques based on DNA analysis, including 16S rDNA sequence analyis, RAPD, rep-PCR, AFLP, RFLP and PCR-RFLP, have been widely used for this purpose. A brief overview of these techniques is required to evaluate their suitability, discriminating power and limitation.