(Evaluation of seed dormancy breaking in Ammoniacum (Dorema ammoniacum

Ammoniacum is a medicinal, industrial and forage plants of Apiaceae that has been destroyed due to excessive utilizations. Ammoniacum seeds have a little germination due to seed dormancy. In order to break seed dormancy an experiment with 22 treatments in a completely randomized design with four replications in seed technology laboratories of Birjand University Agricultural Research was carried out. Treatments were consisting of 6 and 12 hours of leaching, chemical scarification with sulfuric acid solution 80% for 5 and 10 min, potassium nitrate 0.3% for 72 hours, hormone treatments, gibberellic acid (250, 500 and 1000 ppm) and benzyl amino porine (0.1 And 0.25 mg per liter), prechilling for 20 and 35 days at +5 °C temperature, and combined prechilling and hormonal treatments. Results showed that the effect of treatments on percentage, rate, mean germination time and seed vigor of ammoniacum was significant (P>%1). prechilling was an essential factor for dormancy breaking of ammoniacum seed and none of the treatments without prechilling had no effect on germination. The best treatment to overcome seed dormancy was the integrated treatment of perchilling for 35 days and gibberellic acid with 250 ppm concentration. however alonely perichilling be able to breaking seed dormancy in this plant.