Plant growth promoting bacteria effects on growth, photosynthetic pigments and root nutrients uptake of Avena sativa L. under drought stress

     Drought stress is one of the most important factors affecting plant growth. Plant growth under drought stress may be enhanced by the application of microbial inoculation including plant growth promoting rhizobacteria. This research was conducted as a factorial experiment in a completely randomized design. The first factor included the bio-fertilizer (A. vinelandii (A)), P. agglomerans+ P. putida stroin (P), A + P and control (without bio-fertilizer). The second factor was drought stress at three levels of field capacity (FC), 0.7 FC and 0.4 FC. The results showed that treatment A + P at FC level had the highest effect on increasing photosynthetic pigments (p