Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 22, 1997
Publication Date: N/A
Technical Abstract: A phylogenetic analysis using parsimony of 16S rRNA gene sequences (16S rDNA) revealed that species and subspecies of Clavibacter and Rathayibacter form a discrete monophyletic clade, paraphyletic to Corynebacterium species. Within the Clavibacter-Rathayibacter clade, four major phylogenetic groups (subclades) with a total of ten distinct taxa were recognized: 1) species C. michiganensis; 2) species C. xyli; 3) species R. iranicus and R. tritici; and 4) species R. rathayi. The first three groups form a monophyletic cluster, paraphyletic to R.rathayi. On the basis of the phylogeny inferred, reclassification of members of Clavibacter-Rathayibacter group is proposed. A system for classification of taxa in Clavibacter and Rathayibacter was developed based on RFLP analysis of the PCR-amplified 16S rDNA sequences. The groups delineated on the basis of RFLP patterns of 16S rDNA coincided well with the subclades delineated on the basis of phylogeny. The RFLP analyses allowed for rapid differentiation among species and subspecies in the two genera.