Rhizobia nodulating acacias. Biodiversity and taxonomy

Abstract

Bacteria have a wide diversity of mechanisms of cellular rearrangement. This is one of the main respects in which they differ from higher organisms. In the first part of this article, the authors develop the consequences of this where studies of biodiversity and taxonomy are concerned, and review the concepts of taxonomy, genus, species, isolate, biotype, strain, and bacterial diversity. Reference is made to techniques of study and to present knowledge of the taxonomy of rhizobia. The second part explains why the characterization of rhizobia is an important stage in achieving a better use of strains and a better management of field inoculation trials. The diversity of rhizobia able to nodulate the genus Acacia is being studied in two laboratories: the ORSTOM/ISRA laboratory in Dakar, Senegal, is more particularly concerned with the diversity of rhizobia in dry-zone acacias, while the ORSTOM/CIRAD Laboratory in Nogent investigates in humid-zone acacias.