Effect of organic pretreatment on seed germination and enzymes activity of Cumin (Cuminum cyminum L.) under drought stress

Drought stress reduces the germination and growth of plants, and it is very important to provide solutions such as seed priming to increase the uniformity of germination and growth of plants and to deal with drought stress. Thus, a factorial study was conducted in the form of a complete randomized design on cumin seeds in three replications in the Seed Technology Laboratory of Islamic Azad University, Karaj Branch. The treatments of this experiment included: five levels of priming (chitosan, humic acid, vermicompost, distilled water and control (without primer)) and four levels of drought stress (0, -0.3, -0.6, -0.9 MPa). The results showed that drought stress reduced germination percentage, growth and quality of cumin seedlings in no prime conditions and with increasing intensity of drought stress, seedling growth decreased. Priming of chitosan, humic acid and vermicompost were more effective than hydropriming in increasing germination properties as well as drought stress and reducing the negative effects of drought stress, as well as cumin seed priming. The above treatments decreased the proline content and increased ascorbate peroxidase, alpha-amylase and catalase activity. Priming of chitosan (44.02%), humic acid (42.08%), and vermicompost (44.04%) increased the germination of cumin seeds compared to the control (without primer and without drought stress).