Figure 5

Species tree for rhizobia. Consensus unrooted phylogenetic tree estimated by ML methods from the concatenated sequences of dnaK and rpoB housekeeping genes for the rhizobial species indicated aligned using the Geneious Pro Software (Biomatters Ltd). Bootstrap values of >75% are indicated at each node. α, the branch corresponding to α-proteobacteria; β, the branch corresponding to β-proteobacteria. The arrow indicates the predicted intron insertion into the ancestor of S. meliloti/S. medicae.