Rhizobia of Acacia spp.: biodiversity and taxonomy.

Abstract

In the first part of the article, the authors review the concepts of taxonomy, genus, species, isolate, biotype, strain, and species diversity of root-nodulating bacteria (Rhizobium sp. and Bradyrhizobium sp.). The second part discusses the importance of identifying rhizobial species, particularly in the context of field inoculation trials and the utilization of strains. Research in two laboratories into root nodulation of the genus Acacia is outlined: that at the ORSTOM/ISRA laboratory in Dakar, Senegal, has concentrated on the diversity of rhizobia in dry-zone acacias (A. senegal, A. raddiana and A. seyal); research at the ORSTOM/CIRAD laboratory near Paris, France, has been investigating nodules in humid-zone acacias (e.g., A. mangium).