Relationships within the Proteobacteria of plant pathogenic Acidovorax species and subspecies, Burkholderia species, and Herbaspirillum rubrisubalbicans by sequence analysis of 16S rDNA, numerical analysis and determinative tests

Sequence data for 16S rDNA of the type strains of Acidovorax avenae subsp. avenae, A. avenae subsp. cattleyae, A. avenae subsp. citrulli, A. konjaci a nd Herbaspirillum rubrisubalbicans were compared with GenBank library acces sions of Burkholderia spp., Comamonas sp., Ralstonia solanacearum and Vario vorax sp. Maximum Parsimony analysis produced two clusters: 1. Acidovorax s pp., Comamonas sp., and Variovorax sp. (all in the Comamonadaceae), and 2. Burkholderia spp., Ralstonia solanacearum, and Herbaspirillum rubrisubalbic ans. Maximum Likelihood analysis produced only one cluster (of the Comamona daceae). Using nutritional and laboratory tests, all Acidovorax spp., Burkh olderia spp., and Herbaspirillum rubrisubalbicans were discriminated in dis tinct clusters at the species level, and could be identified by selected de terminative tests. There were no phenotypic tests constituted as a circumsc ription of the genera and which permitted the allocation of strains to gene ra. Strain identification as species allowed allocation to genera only by i nference. The nomenclatural implications of these data are discussed.