The Effect of Drought Stress on the Biochemical and Antioxidant Activity of Wheat Genotypes under Foliar Treatments of Growth Stimulants and Zinc Nano Chelate

<p>In order to investigate the effect of different foliar application treatments on the biochemical and antioxidant traits of wheat genotypes under different moisture conditions, a factorial split plot experiment was conducted on the basis of a randomized complete block design with three replications in two locations. The main factors of irrigation (normal and water deficit) and the secondary factors were four levels of foliar application (control (without foliar application), jasmonic acid, zinc nano chelate, and succinate) and three different genotypes of barley. The results showed that water deficit stress reduced the content of chlorophyll a, chlorophyll b total compared to normal irrigation conditions by 9.03%, 6.66%, and 7.32%, respectively, and increased the activity of superoxide dismutase, catalase, and glutathione reductase enzymes by 3.29, 3.48 and 50.90 percent respectively. Foliar application of nano chelate increased the amount of chlorophyll a, chlorophyll b, and total, as well as superoxide dismutase, catalase, and glutathione reductase enzymes, 15.45, 15.76, 14.70, 52.63, and 48.14 percent respectively compared to the control. Mihan cultivar had the highest content of photosynthetic pigments and the lowest activity of antioxidant enzymes. The results showed that foliar application of nano-chelate increased the content of proline, glutathione reductase, and grain yield compared to the control treatment in both normal irrigation and water deficit conditions. Also, foliar application of nano zinc chelate in the Mehen cultivar could produce the highest grain yield and the lowest amounts of proline, glycine betaine, and malondialdehyde. Among the irrigation interaction treatments, line 9 had the highest glycine betaine content in both conditions. It can be stated that foliar application of zinc nano-chelate, along with the appropriate variety, can be a solution to improve seed yield under different environmental conditions.</p>