Isolation and identification of endophytic diazotroph from Cyndon dactylon

The nitrogenase activities of endophytic diazotrophs in Cyndon dactylon were studied by acetylene reduction assay(ARA).The results showed that 24endophytic diazotrophs had been obtained using N-free medium.Significant differences in nitrogenase activities were observed among the endophytic diazotrophs,ranging from 3.45to 383.05μmol·h-1·mL-1.Nitrogenase from the strains of GC-1had the highest activity.Nine strains with higher nitrogenase activity were identified as Klebsiella,Enterobacter,Pseudomonas,Pantoeaand Rhizobium,respectively,by morphological,physiological-biochemical characterization and 16SrDNA sequence analysis.