Assessment of the plant growth promoting potential of some bacterial and fungal isolates under saline stress

Abstract

Salt stress is a major abiotic stress influencing plant growth, development, and crop yield. This study aims to characterize the beneficial effects of some endophytic microorganisms on plant growth. Five bacteria Bacillus subtilis, Aneurinibacillus migulanus, Baillus parenthracis, Brevibacillus invocatus, and Zhiengliuella alba and one fungus, Cladsporium halotoleans were evaluated in vitro for their tolerance to salt under different concentrations (0, 300, 600, 900 mM NaCl). In addition, their potential to produce indole-3-acetic acid and siderophores was also measured. In vivo tests consisted in the determination of the capacity of the tested microbial strains to promote germination and growth of maize seeds under salt stress. Results demonstrated that all the microbial strains tested were tolerant to salinity; however, Bacillus subtilis demonstrated a higher tolerance to salt (900 mM NaCl) compared to the other isolates.