Seed priming with zinc sulfate and zinc chloride affects physio-biochemical traits, grain yield and biofortification of bread wheat (Triticum aestivum)

Zinc deficiency impedes wheat productivity and is major cause of malnutrition in humans consuming wheat products low in Zn, especially in developing countries, which experience low rates of soil and foliar Zn application owing to high cost of chemical Zn fertilisers. This pot study was conducted to evaluate the potential of seed priming with Zn for improving performance and grain biofortification of bread wheat (Triticum aestivum L.). Seeds of wheat cultivars Faisalabad-2008 and Lasani-2008 received one of four Zn treatments involving soaking in aerated solutions of ZnCl2 (0.05 or 0.1 M Zn) or ZnSO4 (0.1 or 0.5 M Zn); untreated seeds were taken as a control. All Zn seed priming treatments improved wheat performance. Seed priming with 0.1 M ZnCl2 advanced seedling emergence, whereas seed priming with 0.5 M ZnSO4 improved leaf elongation/expansion, chlorophyll content, shoot Zn concentration and plant photosynthetic traits. Seed priming with 0.1 and 0.5 M ZnSO4 improved plant water relations. Moreover, seed priming with 0.5 M ZnSO4 improved grain yield (63.1%), and grain Zn concentration (43.1%) and content (93.1%), with low [phytate]:[Zn] compared with non-primed seeds. Faisalabad-2008 performed better than Lasani-2008. In conclusion, seeds of bread wheat may be primed with 0.5 M ZnSO4 as a Zn source for improving plant physiology, yield and grain biofortification.