Isolation and Characterization of Rhizobial Strains from Sesbania

The rhizobial strains 49L, 50M and 51S, as well as 53 from the root nodules of four sesbania specieshave been isolated.They are fast-growing, which produce acid on yeast-mannitol agar and utilize most of carbohydrates as carbon Source.The optimum growth temperature is 25～30℃, grow well at pH 5.5～9.0 andtolerate to 0.5% NaCl.Strain 53 can also grow vigorously at 35℃ and PH 10, tolerate to 1.0% NaCl.Aslow-growing strain 54 from stem nodule of Sesbania rostrata has been isolated.On yeast-mannitol agar, it produces alkali substance.The pH range for its growth is 6～8, optimum is 7.0.It grows well at 25～30℃, tolerates to 1.0% NaCl and utilizes less carbohydrates.When inoculating or cross-inoculating, the host plantsformed nodules with high nitrogenase and hydrogenase activities.