Immunofluorescence studies of selection of strains ofR. trifolii by S184 white clover (T. repens L.)

Abstract

The nodulation of the white clover variety S184 by an effective and an ineffective strain ofRhizobium trifolii was studied using the immunofluorescence technique. The proportion of nodules formed by the effective strain under acid conditions was much higher than would be expected from random infection and was altered in favour of the ineffective strain at the neutral and alkaline pH. Effective nodules also predominated when the effective strain was in the minority in the inoculum compared with the ineffective strain. There was considerable inter-plant variation in nodulation possibly due to the heterozygosity of this outbreeding species. The results are discussed from the point of view of the influence of the host plant in the infection process and in respect of the practice of legume inoculation.