Résumé
Forty-six Frankia strains isolated from nodules of five Casuarina equisetifolia stands throughout Senegal and Gambia were analyzed for their enzyme electrophoretic profiles and compared with six collection strains. These strains were classified into 14 electrotypes, according to their esterase patterns. One or two electrotypes were predominant in each investigation site whereas other electrotypes corresponded to only one strain each. Esterase electrophoretic polymorphism evidenced heterogeneity of a restricted population of Frankia strains belonging to a single genomic species and indicated the high discriminating power of these enzymes for the study of the ecological repartition of Frankia strains in a tropical region.Key words: Casuarina equisetifolia, Frankia, Senegal, enzyme electrophoresis.