Potential of plant growth promoting bacterial consortium for improving the growth and yield of wheat under saline conditions

Abstract

Owing to inconsistent results of a single bacterial strain, co-inoculation of more than one strain under salinity stress could be a more effective strategy to induce salt tolerance. Co-inoculation of more than one bacterial strain could be more effective due to the presence of several growths promoting traits. This study was conducted to evaluate the effectiveness of multi-strains bacterial consortium to promote wheat growth under salinity stress. Several plant growth promoting rhizobacteria (PGPR) had been isolated and tested for their ability to grow in increasing concentrations of sodium chloride (NaCl). Those rhizobacterial strains having tolerance against salinity were screened to evaluate their ability to promote wheat growth in the presence of salinity by conducting jar trials under axenic conditions. The rhizobacteria with promising results were tested for their compatibility with each other before developing multi-strain inoculum of PGPR. The compatible PGPR strains were characterized, and multi-strain inoculum was then evaluated for promoting wheat growth under axenic conditions at different salinity levels, i.e., 2.1 (normal soil), 6, 12, and 18 dS m–1. The most promising combination was further evaluated by conducting a pot trial in the greenhouse. The results showed that compared to a single rhizobacterial strain, better growth-promoting effect was observed when rhizobacterial strains were co-inoculated. The multi-strain consortium of PGPR caused a significant positive impact on shoot length, root length, shoot fresh weight, and root fresh weight of wheat at the highest salinity level in the jar as well as in the pot trial. Results showed that the multi-strain consortium of PGPR caused significant positive effects on the biochemical traits of wheat by decreasing electrolyte leakage and increasing chlorophyll contents, relative water contents (RWC), and K/Na ratio. It can be concluded that a multi-strain consortium of PGPR (Ensifer adhaerens strain BK-30, Pseudomonas fluorescens strain SN5, and Bacillus megaterium strain SN15) could be more effective to combat the salinity stress owing to the presence of a variety of growth-promoting traits. However, further work is going on to evaluate the efficacy of multi-strain inoculum of PGPR under salt-affected field conditions.

Community-forming traits play role in effective colonization of plant-growth-promoting bacteria and improved plant growth

“…The root growth in T4 was higher compared to the other treatments and the control. Similar results were observed in studies by Khan et al. (2022) and Sukeerthi et al.…”

“…The root growth in T4 was higher compared to the other treatments and the control. Similar results were observed in studies by Khan et al (2022) and Sukeerthi et al (2020). Regarding shoot length, the pot with a full dose of fertilizer application showed the highest growth compared to the other treatments, followed by the T4 treatment.…”

The Contribution of PGPR in Salt Stress Tolerance in Crops: Unravelling the Molecular Mechanisms of Cross-Talk between Plant and Bacteria

“…Khan et al [56] evaluated PGP traits and the survival of Enterobacter, Pseudomonas, Rhizobium, and Ensifer fredii under NaCl ranging from 1 to 5%. Enterobacter sp.…”

Unveiling the potential of Halotolerant bacteria as PGPR with an ANOVA and Time-Series enhanced study for sustainable agriculture

“…The seeds underwent surface sterilization involving exposure to 70% ethanol for 1 minute, followed by a 3-4minute immersion in 3.5% Sodium hypochlorite, rinsed thoroughly with autoclaved water. (Asghar et al 2002;Khan et al 2022).…”