Enhancement of Wheat Growth and Zn Content in Grains by Zinc Solubilizing Bacteria

摘要

Two bacterial isolates (B_1 and B_2), recovered from the rice rhizosphere produced siderophore and indole acetic acid and solubilized insoluble phosphate, ZnO and ZnS0_47H_20. Based on routine biochemical tests, both the isolates were characterized asspecies of Pseudomonas. A shift in pH from 7 to 5 was observed in minimal medium supplemented with Zn compounds after 15 days of bacterial growth. Isolate B, solubilized maximum amount of ZnO (1.348ppm) after 15 days of incubation. In a pot experiment on wheat (PBW 373), application of bacterial isolates and their consortium with ZnS0_47H_20 @ 5mM significantly enhanced plant height, chlorophyll, grain number per plant over control after 90 days of sowing. Consortium (B1B2) treated wheat plants showed31% increase in grain Zn over control. HPLC analysis of the root extract of bacterized wheat plants showed the dominance of oxalic, maleic, a-ketoglutaric and fumaric acid. Presence of higher amount of valine and leucine, sugar, protein and phenolic compounds was observed in the root extracts of consortium treated wheat plants than control.