Effect of plant cultivars, Rhizobium strain and mineral nitrogen on ureide production in soybeans, common beans and leucaena

The effects af plent cultivari and utrain of Rhizobium on ureide transport in soybean and mineral nitrogen on ureide production and transport In. soybean (Glycine max (L.) Merrill), common bean (Phaseo/us vulgaris L.) and leucena (Leucaena Ieucocephala Lam.) were studied. No significant differences were found In the percentage of ureides in xylem sap of field grown soybean cv. P1 240-663 which was lnoculated with various Rhizobium strains. Significant differences were however observed between different plant cultivars. Cultivar IAC-5 had the greatest proportion of sap nitrogen as ureides. In the glasshouse, a significant decrease was found In the ureide percentage in the xylem sap of soybean and common bean supplied with nitrate-nitrogen. Applying amrnonium-nitrogen 24 hours before harvesting decreased ureide production only when nitrogenase activity was signif icantly lnhibited. Changes in ureide concentration in root and leaf extracts reflected the changes in nodulation and ureide production of nodulated soybean and common bean but not in Ieucaena.