بررسي تاثير تيمارهاي مختلف بر شكستن خواب بذر گياه بومادران

Achillea millefolium is a self-growing plant, which grown in parts of Asia and Europe, and is very important medical plant. Some studies indicated that 90% of freshly harvested seeds of this species have shown dormancy that cause reduction in seed viability. According to ISTA reports, the dormancy in family of Asteraceae is often physiologic. Five pronances of this species were collected from Ardabil, Challus, Feareidounshahre, Goldasht and Dehagh Paiin and seed dormancy breaking treatments were done in completely randomized design with four replications. These Treatments were: alternative and constant temperatures, dark/light regime (dark 16/light 8), prechilling and using chemical stimulators such as GA3, KNO3 and thiorea. In each test, the germination percentage, speed of germination, velocity coefficient, mean daiiy germintion and correlation coefficient were measured. Variance analysis showed that the best dormancy breaking treatments for A. millefolium seed respectively were a (500 ppm GA3b}0.2% KNO3, dark/iight regime (dark 16h/light 8h) and alternative temperature (20° c/30° c). Also high correlation between germination percentage and speed of germination was observed. This indicates that the speed of germination, also, could be the best indicator for evalution of viability of this species, the duncan test showed that there are significant difference (p<0.01) between pronances, and Feareidunshahre pronance has the highest seed viability about 96%.