Abstract
SUMMARY: On the basis of phenotypic characterization and DNA-DNA homology studies of strains of phytopathogenic Pseudomonas species, it is concluded that P. cepacia is so similar to P. multivorans that the latter name should be regarded as a synonym. On similar grounds, P. alliicola appears to be a synonym of P. marginata. P. caryophylli is a readily distinguishable species. From the DNA-DNA hybridization studies all of these species seem to be related to each other and to the animal pathogens P. pseudomallei and P. mallei.