Evaluation of the effective methods of seed dormancy breaking in medicinal plant of Bilhar (Dorema aucheri)

Bilhar or Mountain Kandall (Dorema aucheri) belongs to Apiacea family that contains flavonoid and coumarine compounds. Since، propagation of this plant in natural habitats occurs through seed and due to deep dormancy، the identification of different seed dormancy breaking methods is necessary for preservation of this species. In this respect، different methods، including chilling، washing and gibberellic acid was studied، on the seeds gathered from Kohgiloyeh and Boyerahmad province. For this reason، a factorial experiment with three factors was done based on completely randomized design in three replications، in the faculty of agriculture، Yasouj University، on 2012. Experimental factors were included، chilling period (stratification periods of 3 and 4 weeks)، gibberellic acid (zero and 1500 ppm) and washing (washing with distilled water and non-washable). Results showed that 4 weeks chilling treatment had maximum germination percentage and germination rate and seedling vigor. Also maximum root and shoot dry weight was obtained from the seeds of this treatment. Whereas، double and triple interaction effects for germination percentage، epicotyl and hypocotyl length were not significant. Germination percentage was better in 4 weeks prechilled seed than 3 weeks. Obtained results from this research showed that Bilhar seeds have the physiological dormancy.