نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 دانشجوی کارشناسی ارشد دانشگاه تربیت مدرس
2 هیات علمی دانشگاه تربیت مدرس
3 دانشجوی دکترای دانشگاه تربیت مدرس
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The objective of present research was to evaluate the effect of seed pretreatment by salicylic acid on germination characteristics of Pinus eldarica Medw. under drought stress. The experiments were carried out based on completely randomized design by factorial arrangement with 3 replications. Treatments were combination of 4 levels of salicylic acid (0 (control), 0.5, 1 and 2 mM for 72 hours) and 5 levels of drought stress (0, -2, -6, -10 and -14 bar by Polyethylene Glycol 6000). After the pre-treatment, seeds were subjected to drought stress in germinator for 40 days. In all pre-treatments, by increasing drought stress, germination percentage, index of germination, germination energy, germination speed, velocity coefficient of Kotowski and vigor index were reduced and mean germination time were increased. Germination of control seeds was ceased in osmotic potentials >-6 bar; in contrast, seed pre-treatment of acid salicylic even in drought stress -14 bar improved germination and other seed germination characteristics. In each drought stress level, in most of seed germination characteristics the best performance was allocated to concentration of 1 mM salicylic acid. Regarding to usage of Pinus eldarica in afforestation and rural and urban green space of arid and semi-arid regions, the seed pre-treatment with salicylic acid may reduce the risks of poor seedling establishment of this species in these regions.
The objective of present research was to evaluate the influence of seed pretreatment by salicylic acid on germination characteristics of Pinus eldarica Medw. under drought stress. The experiments were carried out based on completely randomized design by factorial arrangement with 3 replications. Treatments were combination of 4 levels of salicylic acid (0 (control), 0.5, 1 and 2 mM for 72 hours) and 5 levels of drought stress (0, -2, -6, -10 and -14 bar by Polyethylene Glycol 6000). After the pre-treatment, seeds were subjected to drought stress in germinator for 40 days. In all pre-treatments, by increasing drought stress, germination percentage, index of germination, germination energy, germination speed, velocity coefficient of Kotowski and vigor index were reduced and mean germination time were increased. Germination of control seeds was ceased in osmotic potentials >-6 bar; in contrast, seed pre-treatment of acid salicylic even in drought stress -14 bar improved germination and other seed germination characteristics. In each drought stress level, in most of seed germination characteristics the best performance was allocated to concentration of 1 mM salicylic acid. Regarding to usage of Pinus eldarica in afforestation and rural and urban green space of arid and semi-arid regions, the seed pre-treatment with salicylic acid may reduce the risks of poor seedling establishment of this species in these regions.
کلیدواژهها [English]
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