TAXONOMY OF PSEUDOMONAS SYRINGAE
The evolution of the processes of classification, identification and nomenclature of Pseudomonas syringae are described. Originally referring to a pathogenic species of lilac, in the revision of bacterial names in 1980, P. syringae came to represent more than 40 host specific pathogenic populations, as pathovars. DNA-DNA hybridization studies and recent multilocus sequence analyses (MLSA) indicate a ‘P. syringae complex’ that now encompasses up to ten Pseudomonas species and 60 pathovars of P. syringae. A re-evaluation of the complex using poly-phasic approaches could see the revision of these species and the distribution of pathovars in a number of species or genomospecies. Alternative classifications and nomenclature of these taxa is discussed.