Effect of hydro and osmopriming on seed germination of four medicinal plant Psyllium (Plantago ovata), Fennel (Foeniculum vulgare), Hypericum (Hypericum perforatum L.) and Sisymbrium irio (Descurainia sophia) under salinity stress

In arid and semi-arid soil and water salinity, is one of the most important tensions in limiting production plants. The experiments conducted to investigate the effect of pretreatment with potassium nitrate on seed germination of four medicinal plants Psyllium, Fennel, Hypericum and Sisymbrium irio under salt stress on Seed Science and Technology Laboratory, Shahed University, Tehran. The experimental design was completely randomized with three factors of seed priming, salinity and plant, respectively, three, four and four levels factorial with three replications. Test factors include salinity (zero, 2.5, 5, 7.5 dS.m-1), pre-treatment levels, primed seeds with potassium nitrate (0.3 % for 24 hours) and potassium nitrate (0.6 % for 24 hours) and distilled water (24 hours) and plants Psyllium, Fennel, Hypericum and Sisymbrium. ANOVA results showed that the effect of different levels of salinity and plant on all traits is significant (P ≤ 0.05). Also priming effect on all traits except germination rate was significant (P ≤ 0.01). Effect of salinity on germination percentage, seedling length, primary shoot length, primary root length and seedling fresh and dry weight and seed vigor were significant at the one percent probability level. Also, interaction of priming × salinity and priming × plant on traits germination rate and germination percentage, primary root length, primary shoot length, seedling length and seed vigor were significant at the five percent probability level. The highest of germination percentage achieved in zero and 2.5 dS.m-1 salinity levels at Hypericum plant in terms of hydro priming respectively 94 and 93.33 percentage. Seed vigor under salt stress with hydro and osmopriming showed significant increase in all seed plants other than Sisymbrium irio. Among the species of medicinal plants, Hypericum, Fennel and Psyllium sensitive to salinity, but showed good resistance Sisymbrium irio seeds. The average seed vigor, Sisymbrium irio has a low average, but other species of medicinal seeds (Psyllium, Hypericum and Fennel) has a high average.