摘要：Many, microorganisms playing an important role in plant growth are used in agriculture system, especially these group of microorganisms called plant growth promoting rhizobacteria (PGPR), which can increase the growth of plant directly and indirectly; acting as biofertilizers, phytostimulators and biocontrol agent. Various number of bacteria including species of Pseudomonas, Azotobacter, Klebsiella, Enterobacter, Alcaligenes, Proteus Bacillus, have observed to enhance plant growth. In present study, wild Gossypium species and transgenic Gossypiumhisrsutum sample were collected in monsoon season from four different sampling sites Rhizosphere, Rhizoplane, Endorhizosphere, Bulk soil from Agriculture farm, cotton research centre, Surat, Gujarat. A total Fifty nine bacteria were isolated and in vitro screening was done for different plant growth promoting activities; such as phosphate solubilization, zinc solubilization, Potassium solubilization, Nitrogen Fixation, ACC deaminaseacitivity, phytohormons production, HCN production, ammonia production, Lytic enzymes production, Triphenyltetrazolium tolerance (TTC) activity. In present work, eight bacterial isolates were positive for phosphate solubilization, two zinc solubilization and twenty four potassium solubilization. Nitrogen fixation activity was shown in twenty five isolates. ACC deaminase activity was shown in twenty five isolates. IAA production and Gibberelic acid shown nine and fifty six isolates respectively. Four isolates were positive for HCN production and thirty two for ammonia production. Lipase, protease and amylase enzyme activities were shown twenty three, twenty eight and twenty respectively. Twenty four isolates were tolerance to TTC. From all these traits, eight isolates were showing maximum plant growth promotion activities. As PGPR are environmental friendly and offer sustainable approach to increase production of crop and heath. So PGPR will restrict the use of chemical fertilizer in agriculture area.
