Effect of the Application of Foliar Jasmonic Acid and Drought Stress on Grain Yield and Some Physiological and Biochemical Characteristics of Chenopodium quinoa Cultivars

Water shortage is a critical problem touching plant growth and yield in arid and semi-arid areas such as Iran. Plant hormones such as jasmonic acid (JA) play a crucial role in altering plant morphology in response to stress. To investigate the effect of JA and drought stress on grain yield and some physiological and biochemical characteristics of quinoa cultivars, a split-plot factorial experiment based on randomized complete block design with three replications was conducted at Kerman Agricultural and Natural Resources Research and Education Center over two crop years (2018-2019). In this experiment, drought stress as the main factor in two levels including non-stress and stress based on 60% and 90% soil available moisture depletion and JA foliar application (0, 1 and 2 mg L-1) and cultivars (Giza1 , Titicaca, Q29) respectively, as factorial were sub factor. The maximum grain yield (3775 kg ha-1) was obtained in Giza1 cultivar under non-stress condition and 1 mg L-1 JA foliar application. The greatest grain protein and total chlorophyll content were obtained in Titicaca cultivar under non-stress and 1 mg L-1 JA foliar application by 18.17% and 1.83 mg g-1 fresh leaf weight, respectively. In the opposite trend, the maximum amount of malondialdehyde was observed under drought stress and non-use of JA. In general, given the results of this study, it can be stated that JA caused an increase in grain yield in quinoa cultivars by reducing the harmful effects of drought stress and improving plant growth.