توصيفگر ها :
سرمادهي مرطوب , اندازه گلدان , بستر كشت , درخت بلوط , كيفيت نهال , گونه بومي
چكيده انگليسي :
With the increase in pollution from fossil fuels in industrial and urban areas, the need to increase green spaces is unavoidable. Furthermore, the severe shortage of water resources and climate change in recent years have posed serious challenges to the preservation and maintenance of common plants in green spaces, especially in the central regions of the country, leading to a decrease in plant diversity in urban landscapes, which is contrary to sustainable landscape development. Therefore, the use of drought-resistant, long-lived trees is essential. Oak is one of the long-lived trees, and the habitat of several of its species is in the Zagros and Alborz mountains. Therefore, this research was conducted with the aim of evaluating the impact of different treatments to optimize the propagation and greenhouse seedling production methods of native oak species at Isfahan University of Technology. In this study, seeds of three oak species were collected, including ory oak (Q. macrantera, Gorgan region), Persian oak (Q. brantii, Kohgiluyeh region), and evergreen oak (Q. Ilex, Isfahan city green space). After recording the seed characteristics of all three species, the seeds were subjected to a stratification treatment for 2 weeks. Then, the treated seeds were sown in pots of different sizes (10, 15, and 20 cm in height and 10 cm in diameter) containing soil-based and soil-less growing media. For each species, the experiment was conducted as a three-factor factorial design in a completely randomized basic design with four replications under greenhouse conditions. In total, there were 12 treatment levels for each species, including two levels of stratification (control, 2 weeks of chilling), two levels of growing media (soil-based and soilless), and three pot sizes (10, 15, and 20 cm). The characteristics of emergence percentage and various seed emergence indices, as well as the growth, physiological, and seedling quality characteristics, were evaluated. The results showed that stratification treatment significantly improved seed emergence percentage and indices in all three studied species compared to the control. Additionally, seedling growth characteristics including height, fresh and dry weight of shoots and roots, and seedling quality index were significantly affected by the stratification treatment. The type of growing media affected the growth and quality of oak seedlings, with soil-less growing media having a significant impact on growth indicators such as seedling diameter and length, leaf area, fresh and dry weight, root characteristics, and seedling quality index in comparison to soil-based media in both Q. macrantera and Q. Ilex oak species. The results showed that the growth and quality of seedlings in all three studied species were affected by pot size. In both the Q. macrantera and Q. brantii species, the best seedling quality and highest growth indices were obtained in the largest pot size (20 cm), while reducing the pot size to 15 and 10 cm led to a decline in the quality and growth indices of the seedlings of these species. In the Q. Ilex species, although the 10 cm pot size led to a decline in seedling quality, no significant difference was observed between the 15 and 20 cm pot sizes in terms of growth indicators. Overall, the stratification treatment with a 20 cm pot containing soilless growing media had the most positive impact on the measured indicators of the Q. macrantera species. In Q. brantii, stratification treatment combined with soil or soilless cultivation in 20 cm pots showed the greatest impact on its quality index and growth characteristics.