تأثیر تیمارهای مختلف بر جوانه زنی و شکست خواب بذر کنگر وحشی

In order to investigate different treatment effects on germination in Gundelia tournefortii, three factorial experiments were carried out in the completely randomized design with three replications. The first factor was stratification at 4oC in three levels including 0, 3 and 6 weeks, the second factor was mechanical scarification in two levels including seeds with/without scarification and the third factor was chemical treatments of seed dormancy breaking in three levels including distilled water and gibberellic acid at concentrations of 1000 and 1500 mg/l and Thiourea 0.1%. The results showed that the effects of stratification, scarification and chemical treatments of dormancy breaking and their interactions were significant on all studied parameters (p<0.01). Mean comparison values were significant for the effects of spate treatments together with mechanical scarification for the improvement of all traits. The results also revealed that treatment of mechanical scarification treatment together with gibberellic acid 1000 mg/l in six weeks stratification, due to maximum germination speed, seedling dry weight, seedling length, large-scale germination percentage and seedling vigor index and modest average germination period, was the most influential treatment for seed dormancy breaking of this plant. Correlation between germination percentage with germination rate, dry weight and seedling length was significant. It seems that seed dormancy type in Gundelia tournefortii is physiological and physical, as eliminating physiological and physical factors leads to its germination improvement. &nbsp;