The aim of this study was to select and partially characterize efficient nitrogen-fixing rhizobia associated to pigeonpea from coastal tableland areas in the Northeast of Brazil. Sixteen rhizobia from different coastal tableland areas were evaluated under greenhouse condition, at the Embrapa Coastal Tablelands (Aracaju, Sergipe, Brazil). Four isolates performed better than the others in relation to shoot N content (NC), shoot dry weight (SDW), leaf area (LA) and nodule dry weight (NDW). NDW showed high correlation with SDW, LA and NC. Xylem sap N-ureide/N-total ratio showed high correlation with NC and NDW. The three chosen isolates (R1, R5 and R11) showed fast growth rate and acidified culture medium with mannitol. Compared to R1 and R5, the isolate R11 was more sensitive to the antibiotics and less tolerant to Al and high temperature.
aluminum; antibiotic; N-ureide; temperature; Cajanus cajan