Physiological Responses of Quinoa Varieties (Chenopodium quinoa Willd) to Hydropriming and Drought Stress

This research was carried out in a factorial split plot experiment based on a randomized complete block design with four replications in Semnan Agriculture Research Center, Bastam, central Iran, in 2019. Experimental treatments included irrigation as the main factor at three levels of 100, 75 and 50% of water requirement and sub-factors including cultivar at three levels (Titicaca, Q26 and Q29) and priming at two levels (no priming and hydropriming) as sub-factors. The percentage of water requirement of the plant was calculated using the CROPWAT program and applied from the 6-leaf stage of the plant. The results showed that drought stress reduced leaf area index, 1000-seed weight and grain yield in all three cultivars. Percentage of protein, malondialdehyde, proline, activity of antioxidant enzymes including catalase and ascorbate peroxidase increased in plants under drought stress. Hydropriming increased leaf area index and grain yield. Among the three cultivars tested, hydroprimed plants of Q26 genotype had the highest leaf area index, 1000-seed weight and grain yield compared to the other cultivars. Cultivar Q26 had the highest grain yield when supplied with 75 and 100% of water requirement and Titicaca cultivar had the highest grain yield (1067 kg/ha) in the presence of severe drought stress (i.e. 50% water requirement). In conclusion, Titicaca cultivar was more resistant to drought than other cultivars and cultivation of this cultivar is recommended in Bastam region. In the scope of the research, the application of hydropriming can be suggested to improve the physiological traits of quinoa under drought stress.