H. N. ShelatGupta Dipmala Gopalbhai2017-08-042017-08-042009http://krishikosh.egranth.ac.in/handle/1/5810027350Selection and screening for plant growth hormones production by efficient strains of nitrogen fixers are important steps to optimize high crop yield and improve the sustainability of the ecosystem. The objective of this study was to screen Azospirillum spp. and Acetobacter spp. from the natural endophytic bacterial population for growth hormone production which promote plant growth. In order to select the most efficient isolates, qualitative and quantitative estimation of IAA was done by Salkowski reagent under laboratory condition. Isolates screened, produced indole-3-acetic acid (IAA) ranging in concentration from 5 to 11 μg/ml. Also, screening was done using in situ whatman paper method which confirmed the positive effect of tryptophan on IAA productionenAgricultural MicrobiologyAnalysisThesis