Seed priming alleviates the adverse effects of drought stress on sesame genotypes by improving biochemical and physiological characteristics

An experiment was set up as a split-plot factorial in a randomized complete block design with three replications to investigate the response of sesame genotypes to different seed priming methods under optimal water supply and drought stress conditions. The main factor was irrigation regime at three levels of irrigation after 45 % depletion of available soil water (control), irrigation after 65 % depletion of available soil water (moderate stress), and irrigation after 85 % depletion of available soil water (sever stress). The seed priming at five levels of none-priming (control), priming with pure water, priming with salicylic acid, priming with K2SO4, and priming with ZnSO4 and genotype at three levels (Darab 14, Oltan, and Karaj) were factorially located in the sub plots. The results showed that the moderate and sever stress regimes boosted the H2O2 level, proline and soluble sugars contents, anthocyanin amount, and activity of catalase, superoxide dismutase, peroxidase, and polyphenol oxidase while relative water content, leaf area index, number of capsules per plant, 1000-seed weight, biomass, seed yield, harvest index, and water use efficiency were reduced in such conditions. All seed priming treatments positively improved sesame development and growth under three irrigation regimes by enhancing the plant water content, upregulating the enzymatic and non-enzymatic defense system, and decreasing ROS production. The highest sesame seed yield was recorded in seed priming treatment with salicylic acid, averaging 1152.7 kg ha -1. The Karaj genotype produced the higher seed yield under control, moderate stress, and sever stress regimes (1765.7, 1271.0, and 771.4 kg ha -1, respectively). Overall, the results of the current study suggest that seed priming can be used as a practical solution to reduce the harmful effects of drought stress on the growth and yield of sesame genotypes. Finally, combination of the Karaj genotype pound seed priming with salicylic acid is recommended to obtain the maximum sesame seed yield. (c) 2024 SAAB. Published by Elsevier B.V. All rights reserved.