Taxonomy of citrus bacterial canker
The tug of war on the taxonomy of Xanthomonas campestris pv. citri (EPPO A2 organism) goes on. In 1989, Gabriel et al. proposed a reinstatement of Xanthomonas citri and the creation of the Xanthomonas campestris pathovars citrumelo and aurantifolii (Gabriel et al.; 1989) which were formerly classified as Xanthomonas campestris pv. citri strains. His reclassification was based on restriction fragment length polymorphism (RLFP) analysis. Brlansky et al. (1990) supported this reclassification based on their studies in which they obtained similar results by using membrane entrapment immunofluorescence (see also Reporting Service 508/05).
Now, Young et al. (1991) suggest that the descriptions presented are insufficient in terms of modern practices for the purpose of formal classification in the genus Xanthomonas. The authors consider the pathovars proposed, Xanthomonas campestris pv. aurantifolii Gabriel et al. 1989, and X. campestris pv. citrumelo Gabriel et al. 1989, to be defective in terms of the International Society for Plant Pathology's standards for naming pathovars. However, the EPPO Panel on Bacterial Diseases which has met in Angers (FR) on 1992-03-25/26 considers that the strains corresponding to Gabriel et al.'s names almost certainly do justify description as different pathovars. What now remains is for these to be validly published.
Sources
Gabriel P.W. ; Kingsley, M.T. ; Hunter, J.E. ; Gottwald, T. (1989) Reinstatement of Xanthomonas citri (ex. Hasse) and X. phaseoli (ex. Smith) to species and reclassification of all Xanthomonas campestris pv. citri strains.
International Journal of Systematic Bacteriology 39, 14-22.
Brlansky, R.H. ; Lee R.F. ; Civerolo, E.L. (1990)
Detection of Xanthomonas campestris pv. citrumelo and X. citri from citrus using membrane entrapment immunofluorescence.
Plant Disease 74, 863-868
EPPO Reporting Service 508/5 (December 1990)
Young, J.K. ; Bradburry, J.F. ; Gardan, L. ; Gvazdyak, R.I. ; Stead, D.E. ; Takikawa, Y. ; Vidaver, A.K. (1991) Comment on the reinstatement of Xanthomonas citri (ex. Hasse 1915) Gabriel et al. 1989 and X. phaseoli (ex. Smith, 1987) Gabriel et al. 1989 : indication of the need for minimal standards for the genus Xanthomonas.
International Journal of Systematic Bacteriology 41, 172-177