Page 2 Plant-Bacteria Interactions Edited by Iqbal Ahmad, John ...

64j 4 A Review on the Taxonomy and Possible Screening Traits of Plant Growth Promoting Rhizobacteria
belonged to what became to be referred to as the Agrobacterium–Rhizobium complex
[35]. A more recent tree by Sawada et al. [9], representing the phylogenetic relationships
among legume symbionts and their relatives on the basis of the 16S rDNA
sequence divergence, delineates several groups of genera that will probably have
their taxonomy revised (Figure 4.2).
The groups delineated by Sawada et al.[9]aretheRhizobium–Agrobacterium group
(containing also the genera Allorhizobium and Blastoblaster), the Sinorhizobium–Ensifer
group, the Mesorhizobium group (containing also the non-LNB genera Aminobacter
and Pseudoaminobacter ) and the Bradyrhizobium group (containing also strains of the
Figure 4.2 Phylogenetic relationships among legume symbionts
and their relatives inferred on the basis of the 16S rDNA sequence
divergence. From Sawada et al. [9].