June 2022 | Volume 35 | Issue 2 | Page 449 Pakistan Journal of Agricultural Research Research Article Abstract | Iron (Fe), being an essential micronutrient, is necessary for human health and to maintain the integrity and development of the plant. In Fe-limiting conditions, plants and plant growth-promoting rhizobacterial (PGPR) have a siderophore production mechanism. Inoculation with seed soaking of such siderophore-producing bacteria can be a cost-efective biofortifcation technique. Te current study includes the collection of rhizobacterial isolates from wheat, maize, sorghum, millet, and maize rhizosphere soil of Rawalpindi and Sargodha divisions. Te screening of bacterial isolates for siderophore production through CAS-shuttle assay (quantitative) and CAS-agar (qualitative) was done. Isolates were further characterized for Fe and phosphorus solubilization, indole acidic acid (IAA) equivalents, and organic acid production. Te growth chamber and feld study was planned to evaluate the efectiveness of these isolates on the growth and yield parameters of wheat. Total bacterial isolates were 50, out of which 15 isolates were found signifcantly positive for the production of siderophore and solubilizing of nutrients. Te (SPS10) produced a comparatively high percentage of 46.2 % siderophore units, as shown by results between positive isolates. Out of 15 positive, 7 isolates signifcantly improved root/shoot growth over control in the growth chamber study. Inoculation with siderophore-producing bacteria showed a signifcant increase in plant height, grain yield, spike length, grain weight, no. of tillers plant -1 , and wheat quality in a feld trial. Te results from the current study proposed that in the plant, rhizobacteria can also play a benefcial role in nutrient translocation to plants efciently and nutrients uptake from the soil insoluble form. Shabana Ehsan 1 *, Aneela Riaz 2 , Muhammad Amjad Qureshi 1 , Abid Ali 1 , Ifra Saleem 3 , Muhammad Aftab 3 , Khalid Mehmood 4 , Fakhar Mujeeb 1 , Muhammad Asif Ali 1 , Hina Javed 1 , Fraza Ijaz 1 , Anwar-ul- Haq 5 , Khaliq-ur-Rehman 3 and M. Usman Saleem 4 1 Soil Bacteriology Section, Ayub Agricultural Research Institute, Faisalabad, Pakistan; 2 Soil and Water Testing Lab, Nankana Sb, Pakistan; 3 Institute of Soil Chemistry and Environmental Sciences, Ayub Agricultural Research Institute, Faisalabad, Pakistan; 4 Soil and Water Testing Lab, Toba Tek Singh, Pakistan; 5 Soil and Water Testing Lab, Pakpatan, Pakistan. Received | November 03, 2021; Accepted | June 06, 2022; Published | June 28, 2022 *Correspondence | Shabana Ehsan, Soil Bacteriology Section, Ayub Agricultural Research Institute, Faisalabad, Pakistan; Email: shabanaehsans@ gmail.com Citation | Ehsan, S., A. Riaz, M.A. Qureshi, A. Ali, I. Saleem, M. Aftab, K. Mehmood, F. Mujeeb, M.A. Ali, H. Javed, F. Ijaz, A. Haq, K. Rehman and M.U. Saleem. 2022. Isolation, purifcation and application of siderophore producing bacteria to improve wheat growth. Pakistan Journal of Agricultural Research, 35(2): 449-459. DOI | https://dx.doi.org/10.17582/journal.pjar/2022/35.2.449.459 Keywords | Biofortifcation, Siderophore producing bacteria, Wheat, Field study Copyright: 2022 by the authors. Licensee ResearchersLinks Ltd, England, UK. Tis article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY ) license (https:// creativecommons.org/licenses/by/4.0/). Isolation, Purification and Application of Siderophore Producing Bacteria to Improve Wheat Growth