Some symbiotic characteristics of rhizobia responsible for spontaneous, effective field nodulation of Lotus hispidus

Abstract

Twenty-three strains of rhizobia were isolated from vigorous well-nodulated Lotus hispidus Desf. sown in the field at Milton, N.S.W. The isolates bore no symbiotic resemblance to the strains used as seed inoculant nor to rhizobia isolated from other members of the tribe Loteae. It was concluded that the effective field nodulation of L. hispidus at Milton resulted from infection by rhizobia present at very low levels in the local microflora. L. hispidus rhizobia possessed the unusual characteristic of fixing nitrogen in association with both Lotus corniculatus L. and Lotus pedunculatus Cav. (formerly known as Lotus uliginosus Schk.). Their reaction with L. pedunculatus was good enough to indicate their potential value in commercial inoculants.