Full Length Research Paper

Indole acetic acid production and enhanced plant growth promotion by indigenous PSBs

Sadaf Shahab, Nuzhat Ahmed and Nasreen S. Khan

Centre for Molecular Genetics, University of Karachi, 75270, Pakistan.

*Corresponding author. E-mail: sadaf_shahab99@yahoo.com.

Accepted 18 September, 2009

   Abstract

Indigenous soil samples were tested for Phosphate solubilization. Efficient phosphate solubilizng bacteria were isolated. Effect of four different media on phosphate solubilization were determined. Auxin production by these bacteria were determined via bioassay and high performance liquid chromatography by the bacteria in liquid culture. Indole acetic acid and indole butyric acid were produced by these bacteria in varying concentration with and with out the addition of tryptophan. These bacteria showed stimulatory effects on the growth of root and shoot elongation of mung beans (Vigna radiata). Three promising isolates CMG854, CMG857 and CMG860 were investigated to establish the effect on plant growth. On a comparative basis isolate CMG860 was most promising in promoting plant growth.

Key words: Phosphate solubilizing bacteria, indole acetic acid, indole butyric acid, plant growth, phytohormones, vigna radiate.