Alpha-tocopherol fertigation confers growth physio-biochemical and qualitative yield enhancement in field grown water deficit wheat (Triticum aestivum L.)

Water stress is a major problem to fulfill the world food demand and to solve the problem of malnutrition. Different strategies are being used to solve these problems including the fertigation of plants with different biochemical at different growth stages. The present study was conducted for the induction of drought tolerance in field grown wheat for better yield and nutritional quality through foliar spray of alpha-tocopherol (alpha-Toc) at start of reproductive stage. Water stress was maintained based on number of irrigation. Three levels of alpha-Toc 0.001, 0.01 and 0.1 mM were applied as foliar spray. Water stress significantly reduced the biomass production that associated with the decreased photosynthetic pigments, water relation, photosynthetic efficiency, but increased the lipid peroxidation, leaf relative membrane permeability, activities of antioxidant enzymes and the contents of phenolic, flavonoids, alpha-toc and ASA. Water stress also negatively effected the different yield attributes and seed nutrient quality. Foliar fertigation of wheat plants with alpha-Toc significantly improved the water stress tolerance of wheat plants in term of improvement in growth and seed yield associated with improved water relations, photosynthetic efficiency, contents of photosynthetic pigments and improvement in antioxidative defence mechanism (enzymatic and non-enzymatic antioxidants). Fertigation of water stressed wheat plants with alpha-Toc also improved the seed nutritional quality in terms of the contents of seed phenolics, flavonoids, activities of antioxidant enzymes and the content of alpha-, beta- and gamma-tocopherols. In conclusion, it was found that fertigation of water stressed wheat plants not only improved the water stress tolerance but also improved the seed yield and nutritional quality that will not only be helpful for the improvement in wheat yield that also be a step to solve the problem of malnutrition through the bio-fertification of alpha-Toc.