Antioxidant status and physiological responses of wheat (Triticum aestivum L.) to cycocel application and bio fertilizers under water limitation condition

In order to study antioxidant status and physiological responses of wheat to cycocel (CCC) and bio fertilizers application under water limitation condition, a factorial experiment was cohducted based on randomized complete block design with three replications in 2015. Treatments included water limitation in three levels [normal irrigation (I-1) as control; moderate water limitation (I-2) or irrigation withholding at 50% of heading stage; severe water limitation (I-3) or irrigation withholding at 50% of booting stage]; four bio fertilizer levels [(no bio fertilizer (F-0), seed inoculation by Azotobacter chrocoocum strain 5 (F-1), Pseudomonas putida strain 186 (F-2), Azotobacter + Pseudomonas (F-3))] and four CCC levels [(without CCC as control (Co), application of 400 (C-1) 800 (C-2) and 1200 (C-3) mg/l)]. 3 The results showed that water limitation decreased the chlorophyll-a, chlorophyll-b, total chlorophyll, carotenoid, stomata conductance, leaf area index (LAI) and relative water content of wheat, but activity of catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO) enzymes and proline content were increased. Similar results were observed in CAT, POD and PPO activities due to bio fertilizers and CCC application. Besides the water limitation effects, CCC-treated plants displayed a significant decrease in stomata conductance and LAI. Generally, it was concluded that the application of bio fertilizers and CCC can be a proper tool for increasing wheat yield under water limitation.