Effect of Different Levels of Silver Nanoparticles, Humic Acid and Drought Stress on Seed Germination and Some Morphophysiological Characteristics of Quinoa Seedlings of Titicaca Cultivar

in this study, the effect of silver nanoparticles and humic acid on some morphological characteristics of quinoa seedlings under drought stress was investigated. The experiment was performed as a factorial experiment in a completely randomized design with three replications. The experiment consisted of three levels of silver nanoparticles (0, 10 and 20 mg L-1 AgNPs), three levels of humic acid (0, 100 and 300 mg L-1) and three levels of drought stress (0, -6 and -12 bar). In this study, Titicaca cultivar was used. The highest amount of seed vigor and seed germination rate were observed in the highest level of AgNPs and humic acid, which indicates the positive effect of AgNPs and humic acid on germination percentage, germination rate and quinoa seed vigor. According to the obtained results, drought stress led to a decrease in germination percentage and growth characteristics of quinoa seeds. AgNPs and humic acid had a positive effect on germination and growth characteristics of quinoa seedlings under drought stress conditions compared to control treatment. With increasing the concentration of AgNPs and humic acid, the amount of proline, soluble sugars, total phenol, flavonoids and catalase activity under drought stress increased, indicating the positive role of AgNPs and humic acid to increase drought tolerance in quinoa. Therefore, the use of humic acid at a concentration of 300 mg L-1 along with 20 mg L-1 AgNPs is recommended to improve germination and seed growth of quinoa under drought stress conditions