Breaking seed dormancy and improve germination of four medicinal species of apiaceae under gibberellic acid and prechilling treatments

Apiaceae plants are one of the most important plant families due to high medicinal and economic importance. Existence seed dormancy in this family is one of major obstacles for cultivation and domestication of them. This research was performed to determine the best treatment for breaking seed dormancy and improve germination four key medicinal species seeds of apiaceae family including Ferula assafoetida, Ferula gummosa, Kelussia odoratissma and Carum carvi L. For each specie has been studied 14 treatment including control, prechilling for 10, 20, 30, 40, 50, 70, 90 days, gibberellic acid 200, 400, 600, 800 ppm, integrated treatment gibberellic acid 400 ppm with cold 30 and 70 days in a completely randomized design with four replications. The results showed that four species found significant differences compared to the control by increasing time of cold, density of gibberellic acid, germination percent, germination rate, radicle length, plumule length and seed vigor. Integrated treatment cold 70 days with gibberellic acid 400 ppm were the best treatment for breaking seeds dormancy of Ferula assafoetida (88%), Ferula gummosa (95%), Kelussia odoratissa (87%),also cold treatment 90 days, the best treatment for breaking seeds dormancy Carum carvi L. (87%). According to the results, gibberellic acid treatment could be replaced part of cold needs for breaking seed dormancy, however, it is possible, four species seeds have physiological dormancy type.