The effect of rhizobiophages on the effectiveness of Rhizobium meliloti in symbiosis with lucerne. II. Effects of phages on the R. meliloti strains during passing them through the plant.

Studies were carried out of the effectiveness of Rhizobium meliloti strains reisolated from the roots of lucerne inoculated with effective and non-effective strains in the presence or absence of rhizobiophages. Estimates were made of the changes in phage-sensitivity and lysogeny found in these strains compared with the parent strains. It was found that the character of the reisolated strains depended on the changes brought about by passing through the plant and on the activity of the phages.