Effects of osmopriming at different temperatures on emergence, seedling growth and essential oil of Savory (Satureja Khuzestanica Jamzad) under drought stress

Various species of Satureja genus are growing in different regions of Iran. The drought stress is one of the most unfavorable factors for plant establishment and growth in main parts of the Iran. Germination and emergence of the most plants is affected by environmental stresses including drought and disturbed evnironments. One way to improve seeds and seedlings to cope with stress is seed priming. This research was conducted in order to study the effects of osmo and hydro priming at different temperatures on improving seed and seedling performance of Satureja khuzestanica Jamzad under drought stress conditions. A greenhouse research was carried out as a factorial experiment on the base of a randomized completely block design with three factors and four replications. The factors were including drought stress (50% and 25% of field capacity) with control (75% of FC), osmotic potential of priming (0, -4, -8 bar using PEG 6000) and priming temperatures (15 and 25 ºC). The percentage and rate of emergence, seedling fresh and dry weights, seedling height, vigor index, and leaf area decreased by increasing drought stress but the essential oil content and root length increased. The highest percentage of essential oil observed under 25% FC. Interaction of drought stress and osmotic potential of priming solution was significant on percentage and rate of emergence and vigor index. The interaction of priming temperatures and osmotic potential of priming was significant on the percentage and rate of emergence, vigor index, and shoot dry weight. Hydro-priming at 15 ºC had the most positive effect on the percentage and rate of emergence, fresh and dry weight of seedling, root length, plant height, leaf area, and vigor index. Overall, seed quality was better when priming temperature was lower (15 ºC).