Dormancy breaking and seed germination improvement of two types of verbascum (Verbascum L.) under physical and chemical treatments

Seed germination studies are considered key tools for conservation programs. Since the propagation of verbascum in natural areas is done mostly through seeds, it is necessary to investigate the appropriate methods to eliminate the stagnation of the seeds of this plant. Therefore, the present study investigates the breaking of seed dormancy of V. thapsus and V. kochiiforme species in the form of a completely randomized design with 4 replications. The treatments used included hot water, thermal treatment, physical and chemical scraping, wet cooling and combined treatment of wet cooling and physical scraping. Variance analysis of data and comparison of averages were done using LSD test at the five percent level. The results showed that chilling increased the germination of V. thapsus seeds. Also, the seeds of V. kochiiforme with 1-month chilling along with scratching had better germination than other treatments, and further chilling did not have a significant effect on increasing the germination of this species, but in some cases it led to the activity of fungi, which affected the germination and caused a decrease it became Therefore, according to the increase in germination after chilling V. thapsus, it can be concluded that it has physiological sleep and V. kochiiforme can have physical sleep in addition to physiological sleep due to its hard seed coat. Also, the boiling water treatment not only did not cause the germination of marigold, but also prevented the germination of this plant as an inhibitory factor.