Auxin Producing Plant Growth Promoting Rhizobacteria Improve Growth, Physiology and Yield of Maize under Saline Field Conditions

Abstract

To cite this paper: Iqbal, M.A., M. Khalid, Z.A. Zahir and R. Ahmad, 2016. Auxin producing plant growth promoting rhizobacteria improve growth, physiology and yield of maize under saline field conditions. AbstractSoil salinity is one of the most widespread agricultural problems which reduce the field crop productivity. Salinity disturbs the hormonal balance in plants which results in poor growth. Use of plant growth promoting rhizobacteria (PGPR) is considered an economical and environment-friendly approach to combat salinity stress. This study was carried out to investigate the effect of auxin producing PGPR on the growth, antioxidant status and mineral content of maize (Zea mays) in salt affected soils. Rhizobacterial strains were isolated from the rhizosphere of maize growing under salt affected soil conditions. These strains were screened on the basis of auxin production and their ability to withstand salinity stress. Two stains (MA4 and MA11) which produced highest auxin and tolerated maximum salinity were selected for further evaluation in a field experiment. The results of field trial showed that soil salinity reduced the plant growth, mineral nutrient uptake and yield of maize while antioxidant activity and proline concentration was increased. However, rhizobacterial inoculation improved grain yield (31%), fresh biomass (56%) and phosphorous contents in grains (26%) while the proline concentration (41%), ascorbate peroxidase (59%) and SOD values (42%) in leaves were declined. The results of present study signify the role of auxin producing rhizobacteria under salt affected field conditions.

Evaluation of Brevibacillus brevis as a potential plant growth promoting rhizobacteria for cotton (Gossypium hirsutum) crop

“…1 . Various researchers also reported increased auxin production in response to l -TRP application (Majeed et al 2015 ; Iqbal et al 2016 ). Ahmad et al ( 2008 ) reported that several species of Azotobacter , Bacillus and Pseudomonas produced IAA up to 20, 10 and 25 µg ml −1 , respectively.…”

“…Ahmad et al ( 2008 ) reported that several species of Azotobacter , Bacillus and Pseudomonas produced IAA up to 20, 10 and 25 µg ml −1 , respectively. Iqbal et al ( 2016 ) while carrying out the research under saline field conditions found that the IAA producing rhizobacteria significantly enhanced the growth, physiology and yield of Maize plants.…”

Deciphering the Potential of Rhizobium pusense MB-17a, a Plant Growth-Promoting Root Endophyte, and Functional Annotation of the Genes Involved in the Metabolic Pathway

“…The maximum IAA production by this isolate is 110.5 μg/ml ( Table 3 ). In various studies, it is reported that several rhizobial species enhance IAA and auxin production in response to l -tryptophan during salinity and stress conditions (Iqbal et al, 2016 ). Lebrazi et al ( 2020 ) reported a production of 116 and 105 μg/ml IAA by Rhizobium species.…”

Role of PGPR in the reclamation and revegetation of saline land

“…Inoculation of such PGPR exhibited positive effect on grain weight and yield in maize (Abo-kora, 2016;Ferreira et al, 2013;Noumavo et al, 2013). Zafarulhye et al, (2014) and Iqbal et al, (2016) reported increased growth and grain yield in maize inoculated with PGPR.…”

“…PGPR have been reported to increase chlorophyll content in maize plant under salinity stress (Hassan et al, 2018;Singh & Jha, 2017). Under salt stress, increased accumulation of leaf proline and total soluble sugar content has been reported in many PGPR treated plant species (Upadhyay et al, 2015;Iqbal et al, 2016).…”