Abstract

Plant growth-promoting rhizobacteria (PGPR) are beneficial bacteria that colonize plant roots and enhance plant growth by a wide variety of mechanisms. The use of PGPR is steadily increasing in agriculture and offers an attractive way to replace chemical fertilizers, pesticides and supplements. In the present study, isolation and characterization of PGPR from the rhizospheric soil of wheat was done for the enhancement of wheat growth. Rhizospheric soils samples were collected from different areas of Uttar Pradesh, India. Twenty two (22) isolates of bacteria were successfully isolated, biochemically characterized and screened for their plant growth promoting traits like production of indole acetic acid (IAA), ammonia production, siderophore production and phosphate solubilization. On the basis of multiple plant growth promoting activities among 22 isolates, 17 isolates were also evaluated for their quantitative production of IAA. The isolates Ps-AB4, Ps-BK1 and Ps-JN 2 showed highest IAA production (79.67-110.12 µg/L). Out of 22, 20 and 6 isolates produced ammonia and siderophore, respectively, while 10 isolates solubilized phosphate on the Pikovskaya’s agar medium. The present study reveals that the use of Pseudomonas isolates Ps-AB4, Ps-BK1 and Ps-JN2 as inoculants biofertilizers might be beneficial for wheat cultivation.

Key words: Indole acetic acid, NH₃, Pseudomonas spp., phosphate solubilization, wheat.