Screening of Zinc Solubilizing Plant Growth Promoting Rhizobacteria (PGPR) as Potential Tool for Biofortification in Rice

Aims: Plant growth-promoting rhizobacteria enhance growth by making plant nutrients available to plants under a variety of growing conditions. The study was designed screen zinc (Zn) solubilizing and test their colonization ability in the rice rhizosphere.
 Place Duration Study: experiments were conducted Department Agricultural Chemistry, Bangladesh University, Mymensingh-2202, from January 2019 July 2019.
 Methodology: Initially, thirty-two previously isolated used for screening Zn solid medium. Selected previous quantify solubilization broth culture evaluate root using water agar media chamber. Early seedling monitored two weeks, root-shoot lengths recorded. Eleven tested responded positively ZnO-containing media.
 Results: index (ZSI) positive isolates ranged between 1.08-2.25 after 5 days incubation. Isolate MQ1 solubilized highest both medium (ZSI=2.25) (solubilized 220.20 ppm Zn). bacteria zone also investigated via bio-primed seeds Binadhan-20. Eight 11 (MQ1, MQ2, MQ3, MQ4, OSbr5, OSbr6, EC1, MQL9) showed substantial rhizosphere weeks. germination percentage not increased over control, however, most cases, bio-priming boasted early growth. MQ6 superior performers case shoot growth.
 Conclusion: identified some isolates, revealed colonizing ability, observed promotion. These could be as potential tool biofortification approach rice.