Shahnaz Fathi - Shahid Bakeri High Education Center of Miandoab, Urmia University, Urmia, Iran
Sahebali Bolandnazar - Department of Horticulture, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
Saeedeh Alizadeh-Salteh - Department of Horticulture, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
Fariborz Zaare-Nahandi - Department of Horticulture, Faculty of Agriculture, University of Tabriz, Tabriz, Iran

Today, the use of biological fertilizers in sustainable agriculture is an appropriate alternative to chemical fertilizers because the former can improve the quantitative and qualitative performance of plants, especially under stressful conditions. Therefore, this study aims in greenhouse conditions to investigate the effects of plant growth-promoting rhizobacteria on antioxidant enzyme activities and some physiological traits of sweet basil under water limitation. For this purpose, a factorial experiment was conducted based on a completely randomized block design with three replications. Three levels of water deficit stress factor involved W۰= ۱۰۰% of field capacity, W۱= ۶۰% of the field capacity, and W۲= ۴۰% of the field capacity. Also, biofertilizers factor included nine levels of F۱: Pota Barvar-۲, F۲: Phosphate Barvar-۲, F۳: Azeto Barvar ۱, F۴ (the combination of F۱ and F۲), F۵ (the combination of F۱ and F۳), F۶ (the combination of F۲ and F۳), F۷ (the combination of F۱, F۲, and F۳); F۸ (۱۰۰% chemical fertilizer as a positive control) and F۹ (without any fertilizer as a negative control). Results showed that water limitation increased the activity of ascorbate peroxidase (۱۹۳.۵۵%), peroxidase (۴۱۶.۲۵۸%), polyphenol oxidase (۴۸.۲۱%) enzymes, and essential oil yield (۱۳۵.۴۸%). Meanwhile, the chlorophyll index, carotenoid, and yield decreased under water deficit stress. The use of biofertilizers improved these traits under water limitation conditions and normal irrigation. Also, applying a combination of ۳ biofertilizers (F۷) led to an increase ۲۹.۸۸% in the yield compared with negative control under severe water limitation. Therefore, the use of biofertilizer can be recommended for profitable basil production under water limitation conditions.Abbreviations: Catalase: (CAT), Peroxidase: (PROX), Ascorbate peroxidase: (ASP)

APX, essential oil, carotenoids, POD, PPO