Abstract : Plant growth promoting rhizobacteria (PGPR) are often used as inoculants to promote the growth and yield of agricultural crops, however PGPR strain selection is extremely important. This bacteria colonies plant roots and promote plant growth through a variety of mechanisms including phytohormone production, improved water and nutrient uptake, improved nitrogen availability in the soil, production of ACC-deaminase for ethylene breakdown, phosphate solubilization, siderophore production, phytoremdiation, and phytopathogen defense. Microbial Auxin production is the primary component that promotes healthy plant growth and development. The ability of PGPR to produce phytohormones can be used to boost plant growth, reducing the need for chemical fertilizers and their harmful effects on the environment. The work in this study includes isolation, screening, molecular identification, and applying effective PGPR strains based on their ability to produce auxin in vitro. The soil samples were serially diluted, and the appropriate dilution was placed onto nutrient agar media. Invitro screening was performed on isolated colonies using the Salkowski reagent, which results in a pink coloring. The existence of IAA producers is indicated by the appearance of pink colour. This isolated organism was subjected to DNA isolation after passing morphological and biochemical tests. 16S PCR was used to amplify the isolated DNA. The bacteria was identified as Pseudomonas fluorescence after sequencing and analysing the amplified products with BLAST. When compared to other strains, Pseudomonas has a higher ability to produce auxin. In addition, a pot experiment in plants was carried out to test the influence of auxin (IAA) production by the isolated strain.

Keywords : PGPR , Indole acetic acid ,BLAST

| DOI: 10.17148/IARJSET.2021.81007