Ureide content, nodule type and nitrogenase activity of grain, forage and forest tree legume species

Abstract

Grain, forage and tree legumes were surveyed for ureide content, type of nodules and nitrogenase activity. Thirty-six legume species were studied representing seven tribes of the subfamily Papilionoideae and two tribes of the subfamily Mimosoideae and Caesalpinoideae. Ureides were found in almost all the plant species studied but for many species in very low concentrations. High ureide content was found in nodules, root and stem of legume species belonging to tribe Phaseolus, subfamily Papilionoideae. Those plants are common in tropical regions, have determinant type of nodules and probably evolved towards a form of transport of nitrogen adapted to warm environments. The high ureide contents of these plants were related to high nitrogenase activities of nodules and reflected the origin of ureides from biological nitrogen fixation.