The Effectiveness of Synthesized Zinc-Amino Chelates in Supplying Zinc for Wheat

This pot experiment was carried out to investigate the efficacy of certain Zn-amino chelates, i.e. Zn-glycine [Zn(Gly)2], Zn-arginine [Zn(Arg)2] and Zn-histidine [Zn(His)2] in supplying zinc for wheat was compared with a commercial Zn-sulfate fertilizer. Three wheat cultivars, differing in Zn-efficiency, including Back Cross Rowshan, Kavir and Durum were planted at Research Greenhouse of Isfahan University of Technology, Isfahan, Iran, in 2010. Fertilizer treatments were applied at planting and tillering stages, with 20 mg Zn per kg soil. Results showed that soil application of Zn fertilizers increased shoot Zn content of all three wheat cultivars in comparison with control (no addition of Zn) treatment. Shoot Zn content of Durum cultivar treated with Zn(Gly)2 was 33.3% higher than Zn-sulfate. The effect of Zn-amino chelates on activity of catalase (CAT) and ascorbate proxidase (APX) was dependent on the amino chelate type and wheat cultivar. Zinc-amino chelates resulted in increase of CAT activity in the leaves of Kavir and Back Cross Rowshan cultivars, while they were ineffective in Durum cultivar. In all three wheat cultivars, leaf activity of APX was also significantly increased by Zn(His)2 and Zn(Arg)2 over the Zn-sulfate treatment. According to the results of the present study, Zn-amino chelates could play more effective role in improving plant Zn nutrition status and increasing yield and seed quality of wheat by increasing Zn uptake and activities of CAT and APX enzymes.