The nearly complete, PCR-amplified, 16S rRNA gene sequences have been determined from the representative type strains of eight xanthomonad phena, including six validly described species of the genus Xanthomonas and Stenotrophomonas maltophilia. Pairwise sequence comparisons and phylogenetic analysis demonstrated that the xanthomonads comprise a monophyletic lineage within the γ-subclass of the Proteobacteria. Although the genus Xanthomonas was observed to comprise a cluster of very closely related species, the observed species-specific primary sequence differences were confirmed through sequencing additional strains belonging to the respective species.
Moore, E.R.B.; Kruger, A.S.; Hauben, L.; Seal, S.E.; De Baere, R.; De Wachter, R.; Timmis, K.N.; Swings, J. 16S rRNA gene sequence analyses and inter- and intrageneric relationships of Xanthomonas species and Stenotrophomonas maltophilia. FEMS Microbiology Letters (1997) 151 (2) 145-153. [DOI: 10.1111/j.1574-6968.1997.tb12563.x]