Ecology of the Root-Nodule Bacteria of Legumes

Abstract

Antisera prepared against 58 strains of root-nodule bacteria and against 16 strains belonging to the genus Agrobacterium were tested against 113 strains of Rhizobium, 20 strains of Agrobacterium and 20 strains of other, possibly related, bacteria. Three serologically distinct groups of root-nodule bacteria were noted: (1)Rh. trifolii, Rh. leguminosarum and Rh. phaseoli; (2)Rh. lupini, Rh. japonicum and Rhizobium spp.; (3)Rh. meliloti. Strains of Rh. meliloti showed serological affinities with A. radiobacter and A. tumefaciens. All groups showed wider flagellar than somatic agglutination, and many different serotypes were apparent. The groupings obtained from this investigation are compared with those derived from other taxonomic studies, and the use of serological methods in rhizobial classification is discussed. © 1963 Swets & Zeitlinger.