OICC Press Journal of Rangeland Science 2423-642X 15 1 2025 01 20 Enhancing the Emergence Characteristics of Three Populations of Mountain Thyme (Thymus kotschyanus) Using Different Priming Methods 1 7 10.57647/j.jrs.2025.1501.09 EN Mohammad Ali Alizadeh Research Institute of Forests and Rangeland, Agricultural Research, Education and Extension Organization, (AREEO) Tehran, Iran Mohaddeseh Forozesh Biology Department, Faculty of Science, Payame Noor University, East Tehran Center, Tehran, Iran Hamid Sobhanian Biology Department, Faculty of Science, Payame Noor University, East Tehran Center, Tehran, Iran Gholomrezah Bachshi khaneki Biology Department, Faculty of Science, Payame Noor University, East Tehran Center, Tehran, Iran Ali Ashraf Jafari Research Institute of Forests and Rangeland, Agricultural Research, Education and Extension Organization, (AREEO) Tehran, Iran https://orcid.org/0000-0002-1211-3796 Journal Article 2025 01 20 The aim of this research was to determine the emergence ability of seeds and seedling vigor of three populations of Mountain thyme (Thymus kotschyanus) using different priming methods. A factorial experiment was conducted based on a Completely Randomized Design (CRD) with three replications in Research Institute of Forest and Rangeland, Tehran, Iran in 2016. In this experiment, factor A was: three populations of Tehran, Gazvin and Zanjan, and factor B was seven levels of priming such as: osmopriming [PolyEthylene Glycol (PEG) 0.6 and 0.9 MPa], hormonal priming [Gibberellic Acid (GA 250 and 500 ppm], matrix priming (perlite), Hydro priming (distilled water) and control (without priming). The primed seeds and control were sown in 2 kg capacity pots at a depth of 1 cm and the pots were kept in greenhouse conditions (the temperature of 20-30°C during the day and 5-12°C at night). The emergence traits including the percentage and speed of emergence, root and shoot length, seedling length, seedling vigor index, seedling fresh and dry weight, Root to Shoot length ratio (RS) and seedling Dry Matter (DM%) were measured. The statistical analyses and comparison of means were done using SAS 9.1 software. Tukey test method was used to compare the mean of data (p<0.05). The results of analysis of variance showed a significant effect of population (p<0.05) for speed of emergence and plant DM%. The effect of priming treatments was significant for all traits and the priming by population interaction effect was significant for the traits of speed of emergence, root shoot length ratio and plant dry weight. The Tehran population with average values of emergence percentage (64.98%), and speed of emergence (4.98 sprouts/day) had the highest emergence appearance and speed of emergence, respectively. In comparison, between treatments, the highest value of speed of emergence (5.40) was obtained using PEG 0.6 MPa. The highest stem and seedling’s length with values of 65.7 and 31.4 mm were related to hormonal priming GA (250 and 500 ppm), respectively. The highest fresh seedling weight (39.44 mg) was obtained by hydropriming. According to the results, it was concluded that the Osmopriming (PEG) and hormonal priming (GA) were effective priming methods for seedling establishment.