Effect of super absorbent application on destructive oxidative stress in canola (Brassica napus L.) cultivars under water stress conditions

Drought stress significantly limits canola (Brassica napus L.) growth and,crop productivity. Hence, efficient management of soil moisture and study metabolic changes which occur in response to drought is important for agricultural production of this crop. For a better understanding of drought tolerance mechanisms and improving soil water content management strategies, an experiment was laid out in a randomized complete block design with factorial split arrangement with three replications. Irrigation strategy and super absorbent application were allotted to main plots. Irrigation strategy had two levels : 80% of evaporation as control (I-1) and drought stress started from flowering stage (I-2). Application of super absorbent had two levels : Non-application of super absorbent as control (S-1) and application of super absorbent with 7% concentration. Cultivars (Rgs 003 (V-1), Sarigol (V-2), Option 500 (V-3), Hyola 401 (V-4), Hyola 330 (V-5) and Hyola 420 (V-6) were allotted to sub-plots. Plants under water deficit stress and application of super absorbent showed a significant increase and decrease, respectively, in malon dialdehyde, dityrosine and hydroxy deguanosine contents in leaves compared with control plants. In this context, plants with higher levels of antioxidants showed higher resistance to these stress conditions and higher yield and dry matter allocation to grain filling process i. e. harvest index. Our results suggest that drought stress leads to production of oxygen radicals, which results in increased lipid, protein and nucleic acids peroxidation and oxidative stress in the plant. In conclusion of present study, application of super absorbent polymer could reserve different amounts of water in itself and so increases the soil ability of water storing and preserving and at last in water deficiency, produce plant water need and approve its growth under postanthesis water deficiency.