Symbiotic relationships between native ecotypes of Desmodium incanum and rhizobia in Uruguay

Abstract

Desmodium incanum is a herbaceous legume native to Uruguay. lts perennial characteristics and good adaptability make this legume interesting far animal nutrition and introduction in agricultural management practices. The research on native legume species well adapted to diverse ecological conditions, is an important subject for the agronomic potential that many species show. The objective of this work was to assess the nodulation status in the field and the nitrogen-fixing capacity of rhizobial strains isolated from native D.incanum and to establish the nodulation specificity with these and other rhizobial strains. This legume is well nodulated in the field and its nodulation is specific. None of the rhizobial strains isolated from other legume species (native or exotic) nodulated D.incanum. There were differences among the ecotypes studied in their symbiotic behaviour. ¹⁵N methods permitted differentiation of the N-fixing capacity of rhizobial strains.