Germination improvement in seeds of gum ammoniac

Gum ammoniac (Dorema amoniacum), is a perennial forb which its gum resin is used in traditional medicine of Iran and also widely used in food, cosmetic and detergent industries. Habitats of this species are seriously disturbed by conversion of natural ecosystems to rainfed farms. Recovery of natural habitats by seed planting can be a suitable strategy to conserve this valuable plant, therefore dormancy and germination requirements were investigated in seeds of this species. Seeds were subjected to interact in different temperatures consisting of (3, 6, 9, 12 and 15 ºC), and washing or not washing. So, a completely randomized design with 25 factorial experiments was used for conducting and analyzing the data. Results indicated that whased seeds had no significant effects on germination percentages. The optimum temperature for this plant was observed at 3ºC and increasing of temperatures decreased the germination percentages of the seeds. The lowest germination percentage (0%) was recorded at 15 ºC. Therefore, in machinery planting of this species, the better plan is to use the suitable time of sowing.