| چکیده انگلیسی مقاله |
Background and purpose: The Sumac shrub is a commonly used species for afforestation in arid and semi-arid areas to reclaim land. Additionally, the fruits of Sumac are used to support the economy of local communities. The purpose of this study is to analyze the type of dormancy exhibited by Sumac seeds, and to determine the effects of different dormancy breaking treatments. These treatments include scratching the seeds, treating them with boiling water, sulfuric acid, cold layer, and gibberellic acid (GA3) to increase the rate of germination.
Materials and methods: A study was conducted at the Forest Tree Seed Technology Laboratory of the Department of Forestry, Faculty of Natural Resources, University of Tehran. The study was conducted in four replicates of 50 seeds using a completely randomized design. The first step was to measure the survival percentage of the seeds using the tetrazolium test, which was found to be 85.5%. The study involved different treatments applied on sumac seeds. The treatments without the presence of gibberellic hormone included: A) Boiling water treatment with three cold layer durations of 2, 4 and 6 months, B) Chemical scraping treatment with 96% sulfuric acid at three levels of 40, 80 and 120 minutes and three cold layer durations of 2, 4 and 6 months, C) Chemical scraping treatment with 96% sulfuric acid in three levels of 40, 80 and 120 minutes and boiling water treatment and three durations of the cold layer of 2, 4 and 6 months. The treatments with the presence of gibberellic acid hormone included: A) Treatment with boiling water and cold layer in three periods of 2, 4 and 6 months and gibberellic acid at three levels of 250, 500 and 1000 P.P.M, B) Treatments with sulfuric acid for 80 minutes and cold layer in three periods of 2, 4 and 6 months and gibberellic acid in three amounts of 250, 500 and 1000 P.P.M, C) Treatments with sulfuric acid for 80 minutes, boiling water and cold layer in three periods of 2, 4 and 6 months and gibberellic acid in three amounts of 250, 500 and 1000 P.P.M.
Findings: The analysis of variance for germination speed confirms that there is a significant variation in the average germination rates between different treatments. The average germination rates for the sulfuric acid treatment, which involved boiling cold water for 120 minutes over a period of two months, was 7.96. This treatment showed a significant difference in growth compared to the control treatment, which had an average growth rate of 96.7. Similarly, the 2-month cold broth treatment had an average germination rate of 7.61, which was significantly different from the control treatment. The Gibberellic acid 500 ppm cold decoction treatment for 6 months resulted in a significant growth rate of 18.75, which was significantly different from the control treatment. Finally, the Gibberellic acid 250 ppm + boiling water + cold treatment for 6 months had an average germination rate of 15.79 and showed a significant difference in growth compared to the control treatment.
Conclusion: According to the results, sumac seeds exhibit both physical and physiological dormancy. The treatment of scraping with sulfuric acid followed by a cold layer did not have a significant impact on dormancy breaking and germination. However, the use of gibberellic acid improved both the percentage and speed of germination, with the best results obtained using a treatment of 500 ppm gibberellic acid along with boiling water and cold storage for six months, resulting in a germination rate of 18.79%.
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