Morphophysiological characterization of rhizobia isolated from wild genotypes of the common bean

This study aimed to characterize, based on the morphology and on the use of carbon sources, rhizobial isolates obtained from nodules of wild common bean genotypes cultivated on soil samples from the states of Goias, Minas Gerais and Parana. Based on morphological and carbon source use, similarity matrixes were generated to perform clustering analysis based on the Jaccard index. A total of 523 isolates were obtained with the predominance of isolates that acidify the culture medium and showed fast growth. Isolates from the soils of Araucaria and Prudentopolis produced a greater amount of mucus than those from Jussara, Nova Veneza, Uberlândia and Unai soils. The rhizobia isolates obtained from soils of Goias and Minas Gerais showed greater phenotypic diversity than those from the soils of Parana. Analysis based on the use of different carbon sources revealed that rhizobia isolates obtained from soils of Goias have higher metabolic diversity. Overall, the most part of isolates grouped with the reference strains, especially with the Rhizobium tropici and R. freirei strains used as inoculants for the common bean.