Evaluation of the potential of multi-trait PGPR isolates as inoculants for maize (Zea mays L.) growth

Ebrahim  Eshaghi; Sara  Mousae; Ali  Hendiyani; Alireza Habibi  Khave; Rahim  Nosrati

doi:10.18502/ijm.v16i6.17260

Ebrahim Eshaghi Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
Sara Mousae Department of Biology, Nourdanesh Institute of Higher Education, Meymeh, Isfahan, Iran
Ali Hendiyani Department of Textile Engineering, Islamic Azad University, Science and Research Branch, Tehran, Iran
Alireza Habibi Khave Department of Organic Chemistry, Payame Noor University, Tehran, Iran
Rahim Nosrati Cellular and Molecular Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran

DOI: https://doi.org/10.18502/ijm.v16i6.17260

Keywords: Bio-fertilizer; Plant growth regulators; Rhizobacteria; Siderophore; Zea mays

Abstract

Background and Objectives: Plant growth-promoting rhizobacteria (PGPR) with a diverse set of traits can improve crop yield in agriculture. The current study aimed to evaluate the potential of multi-trait PGPR isolates as inoculants for maize (Zea mays L.) growth.

Materials and Methods: In this study, 23 bacterial isolates were initially screened from maize plant rhizosphere. Ten iso- lates (A1–A10) were selected based on N fixation, P and K solubilization and their in vitro specific PGPR traits, such as solubilization of Zn, and Mn, the production of IAA, siderophore, ammonia, and HCN were assayed. Finally, the potential of selected isolates in enhancing the germination, height, shoot collar diameter, shoot fresh and dry weight biomass, and root dry weight of maize were evaluated.

Results: Among the positive-PGPR colonies, the selected isolates demonstrated the better performance of PGPR traits such as highest nitrogen fixation, P, K, Mn, and Zn solubilization, and production of siderophore, HCN, NH3, and IAA. In addi- tion, the maize seed germination and improvement of maize yield in a pot experiment were observed after their treatment by bacterial inoculants. Biochemical characteristics, 16S rDNA amplification, and sequencing demonstrated a high similarity of PGPR isolates to the strains of Enterobacter, Pantoea, Kluyvera, Lelliottia, Klebsiella, Pectobacterium, and Stenotro- phomonas.

Conclusion: The findings demonstrated that these strains could prove effective PGPR inoculants for the improvement of maize crops as multiple bio-fertilizers.