Patterns of symbiotic behaviour in Trigonella L.

Abstract

The symbiotic behaviour of five species of Trigonella in combination with 19 strains of Rhizobium melloti were examined in bacteriologically controlled culture. Nodule formation occurred in all but 10 of the symbiotic combinations and, on the basis of nodulation, there were three groups of host plants and three distinct types of Rhizobium. In respect of nitrogen fixation, which took place in 41 of 92 combinations, each species behaved differently and the rhizobial strains formed seven groups. Nitrogen fixation relationships fell into orderly patterns of increasing specificity.

The data provide a basis for selection of suitable inoculants for Trigonella.