Abstract

Plant growth promoting rhizobacteria have gained extensive importance worldwide. These are naturally occurring bacteria that actively colonize the plant roots and improve plant growth. Plants inoculated with some potential PGPR strains exhibit improved biomass production. It has been observed that PGPR exert their growth promoting effects on plants by utilizing a number of mechanisms. Taken as an example, PGPR improve legumes growth due to their potential involvement in nitrogen fixation. Supply of nutrients like phosphorous, copper, iron, sulphur etc. is enhanced in the plants having rhizosphere enriched with plant growth promoting rhizobacteria. PGPR also act as bio-control agents by imposing their negative effects on the growth of disease causing bacteria, fungi and help in controlling insect pests. The research on PGPR has been on rise for the past few decades and several products containing PGPR have been commercialized for their use in agriculture. The more emphasis of scientists on these PGPR is due to the fact that these could only be the best alternative for the chemical products being utilized on a wide scale for getting improved yield. These chemical products are known to add to the pollutants prevailing in our environment. Therefore, the focus of this review is on the potential characteristics of PGPR that make them suitable alternative for chemical products being extensively exploited in agricultural practices.

Key words: PGPR, Nitrogen fixation, Bio-control agents