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The most of medicinal plants seeds have dormancy under normal conditions, therefore, it is necessary to know the affective factors on seed dormancy and creation optimal conditions for their germination to extensive cultivation of medicinal plants. Dracocephalum kotschyi is an important Iranian endemic herbs which is extinting in the Lamiaceae family. This research was conducted in order to find the most effective treatment to break seed dormancy, which is one of the major problems cultivation on a large scale and rehabilitation in the natural areas. Experimental treatments including of scarification with sand paper, 95% sulfuric acid in 3 and 6 min and their combination, gibberellic acid (125, 250 and 500 µg ml-1), nitrate potassium (% 0.2 and %0.4 in 2 times) and also for moist chilling was at (5°C for 24, 48 and 72 hours) as compare to control (watering in 24 and 48 hours). The experiment was done base on the completely randomized design (CRD). The obtained results indicated that, there was a significant difference (p-value< 0.01) between in treatments of scarification with sand paper and 95% sulfuric acid on germination percentage, germination rate, vigor index, fresh and dry weight of the plumule and radicle. The results showed that sulphuric acid treatment in 3 minutes increased significantly seed germination as compare to control and other treatments. Obtained results represents that the presence of seed hard shell and high mucilage is a physical barrier and acts as a limiting factor in the germination of dragonhead by preventing the spread of embryos or by limiting the absorption of water and gas exchange. So, application of some treatments like scarification and hormonal treatment such as gibberellin could be improved the germination of dragonhead. [ABSTRACT FROM AUTHOR]

In program of increasing forage production in rangelands of the country, gathering and deepening knowledge of forage plants establishment is necessary. So seeds of Trifolium pratense species prepared from Sari city market and cultivated. The purpose of this study was to determine the optimal season and efficient method of species establishment for rangeland breeding in steppe rangelands. Experiment was performed in Posht-kooh water spreading station with 350 mm precipitation and semi-arid-cold climate. For this purpose, two sowing treatments including of seeding and seed spacing in two cultivation season of fall and spring, in split plot based on completely randomize block design in three repetitions were performed. Results indicated that there was a significant difference at (p<0.01) between the cultivation season and two cultivation methods. Germination and viability in fall season (39.11% germination, 13.83% viability) were more preferable to spring cultivation (30.06% germination, 11.83% viability). Seed cultivation in seeding (germination 39.22%, 14.78% viability) was also superior to seed spacing (29.94% germination, 10.89% viability). According to the obtained results, fall cultivation and seeding method were better than spring cultivation and seed spacing method. There is possibility of breeding rangelands in similar climatic and physical properties of the rangelands at the test site as well as fall cultivation and seeding method to increase forage production and direct grazing. [ABSTRACT FROM AUTHOR]