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Azospirillum lipoferum strain (GQ 255949) exhibits the ability to mitigate stress conditions. The present study was carried out to evaluate the biocontrol and salt tolerance potential of A. lipoferum and to examine its ability to mitigate salt stress in wheat crop when inoculated. A. lipoferum has shown strong biocontrol potential against Aspergillus niger and Pseudomonass spp. Strain exhibited the survival efficiency uptill 150 mM NaCl and also showed production of different osmolytes such as proline, soluble protein, soluble sugars and Super oxide dismutase while growing under saline conditions. Although salinity affected growth and metabolism of wheat, A. lipoferum inoculation significantly ameliorated its effects by improving the germination and plant growth, particularly under higher salinity levels (50 mM, 100 mM and 150 mM NaCl). Maximum impact of inoculation was observed at 150 mM NaCl. Chlorophyll content and membrane stability improved with inoculation resulting in 38.6% and 15.3% at 150 mM NaCl. Highest increase in concentration of osmolytes was 35.6% in proline, 28% in soluble sugars, in inoculated plants as compared an un-inoculated wheat plant under saline condition. It is concluded from the present findings that A. lipoferum strain (GQ 255949) has potential to promote growth of wheat plants under saline conditions.

Crude oil contamination is a serious environmental threat to soil and plants growing in it. Biochar has the potential of biostimulation for remediation of crude oil-contaminated soil. Therefore, the current research was designed to analyze the bio-stimulatory impact of biochar for remediating the crude oil contaminated soil (10%, and 15%), and growth of maize under glasshouse conditions. Biochar was produced by pyrolysis of Australian pines at 350 °C. Soil incubations were done for 20 days. The results of soil analysis showed that the crude oil degradation efficiency of biochar was 34%. The soil enzymatic activities had shown 38.5% increase in fluorescein diacetate (FDA) hydrolysis and 55.6% increase in dehydrogenase activity in soil incubated with biochar in comparison to control. The soil microbial diversity was improved to 41% in biochar treated soil with respect to untreated one, while microbial respiration rate had shown a 33.67% increase in soil incubated with biochar with respect to control under oil stress. Gas Chromatography Mass spectrometry (GC-MS) analysis had shown the high content of low molecular weight hydrocarbons (C 9 -C 13 ) in the soil incubated with biochar in comparison to untreated soil. Biochar showed a significant increase in fresh and dry biomass (25%, 14.61%), leaf area (10%), total chlorophyll (11%), water potential (21.6%), osmotic potential (21%), and membrane stability index (12.7%). Moreover, biochar treatment showed a higher increase in the contents of proline (29%), total amino acids (18%), soluble sugars (30.4%), and antioxidant enzymes like superoxide dismutase (16.5%), catalase (11%), and peroxidase (12%). Overall, the results of the present study suggest the bio-stimulating potential of biochar for degradation of hydrocarbons in crude oil contaminated soil and their growth-stimulating effects on maize.