Response of some physiological and morphological properties of quinoa (Chenopodium quinoa Willd.) by zinc application under drought stress

Iran, is classified as arid and semi-arid regions of the world. Therefore, it is important to identify and planting of drought tolerant plants such as quinoa (Chenopodium quinoa Willd.). Zinc is involved in vital processes of the plant therefore; the supply of this element to the plant has a major impact on the quantity and quality of production. This study was conducted as a pot experiment to investigate the effect of zinc sulfate on quinoa under drought stress in a factorial randomized complete design with three replications. Drought stress was prepared with PEG 6000 at four levels (0, -3, -6 and -9 bar) and zinc element from zinc sulfate source with four levels (2 (control), 4, 6, and 8 μM) and in the four-leaf stage, the treatments were applied simultaneously to Hogland's nutrient solution for two weeks. According to the results, an increase in drought stress caused a 68% increase in catalase compared to the control. Maximum leaf soluble protein at -6 bar level with 8 μM zinc sulfate level, highest total soluble sugars and leaf proline at the highest level of drought and 6 μM zinc sulfate were observed. With increasing drought, chlorophyll a (34%), chlorophyll b (187%) and leaf carotenoid increased two-fold but decreased shoot dry weight (38%) and leaf area (37%) compared to control. In general, the use of zinc reduced the damage caused by drought stress by improving the level of osmolytics, and to alleviate the effect of drought stress, the use of 6 μM zinc sulfate in nutrient solutions is recommended.