Phylogenetic tree of genes from the Rfo alleles. The sequence of the related gene BnPPR-B-LIKE1 from Brassica napus (accession number FJ455099)  was used as an outgroup to root the tree. The analysis was performed on the Phylogeny.fr platform (see details in Material and Methods). Reliability for internal branches was assessed using the bootstrapping method (500 bootstrap replicates). Bootstrap results are indicated in red. Graphical representation and editing of the tree were performed with TreeDyn (v198.3) .