INDOLEACETIC ACID PRODUCTION BY RICE PLANT GROWTH PROMOTING RHIZOBACTERIAMANINDER DHALIWALAbstract Rhizosphere-living bacteria that exert a global beneficial effect on plant growth are referred as plant growth promoting rhizobacteria (PGPR). Presently, PGPR include representatives from very diverse bacterial taxa. The modes of action of PGPR involve complex mechanisms to promote plant growth, development and protection. Important among them are biofertilization (increasing the availability of nutrients to plant), phytostimulation (plant growth promoting, usually by the production of phytohormones) and biocontrol (controlling diseases, mainly by the production of antibiotics and antifungal metabolites, lytic enzymes and induction of plant defense responses). Most of the organisms produce IAA in presence of tryptophan. In present study it was observed that as the concentration of tryptophan in the medium increases, the amount of IAA produced increased. Out of the 29 bacterial isolates derived from rice plant, isolate T6 was found to be efficient producer of IAA and was identified as Rhizobium. Using different concentrations of tryptophan from (1mg/mL–5 mg/mL) in the medium, IAA production increased within 24 hrs. Under variable tryptophan concentration the isolate T6 showed maximum production at 3 mg/mL of tryptophan concentration.
Enter your contact information below to receive full paper.
|