اﺛﺮ ﭘﯿﺶﺗﯿﻤﺎر ﺑﺬور ﺑﺎ ﺟﯿﺒﺮﻟﯿﮏ اﺳﯿﺪ ﺑﺮ ﺷﺎﺧﺺﻫﺎي ﺟﻮاﻧﻪزﻧﯽ ﻋﻠﻒ ﮔﻨﺪﻣﯽ ﺗﺤﺖ ﺗﻨﺶ ﺧﺸﮑﯽ

Gibberellic acid priming effect on Agropyron elongatum seed germination indices under drought stress

ﭘﯿﺶﺗﯿﻤﺎر ﺑﺬر ﻣﻮﺟﺐ ﺑﻬﺒﻮد ﺻﻔﺎت ﺟﻮاﻧﻪزﻧﯽ و اﺳﺘﻘﺮار ﮔﯿﺎﻫﭽﻪ و اﻓﺰاﯾﺶ ﮐﺎراﯾﯽ ﺑﺬر در ﺷﺮاﯾﻂ ﺗﻨﺶﻫﺎي ﻣﺤﯿﻄﯽ ﻣﯽﺷﻮد. ﺑﻪ ﻣﻨﻈﻮر ﺗﻌﯿﯿﻦ اﺛﺮ ﭘﯿﺶﺗﯿﻤﺎر ﺟﯿﺒﺮﻟﯿﮏ اﺳﯿﺪ ﺑﺮ رﻓﺘﺎر ﺟﻮاﻧﻪزﻧﯽ ﮔﯿﺎه ﻣﺮﺗﻌﯽ ﻋﻠﻒ ﮔﻨﺪﻣﯽ )Agropyron elongatum( ﺗﺤﺖ ﺷﺮاﯾﻂ ﺗﻨﺶ ﺑﺤﺮاﻧﯽ ﺧﺸﮑﯽ ﺑﺎ اﺳﺘﻔﺎده از ﭘﺘﺎﻧﺴﯿﻞ 12- ﺑﺎر اﯾﺠﺎد ﺷﺪه ﺑﺎ ﭘﻠﯽاﺗﯿﻠﻦﮔﻼﯾﮑﻮل، آزﻣﺎﯾﺸﯽ ﺑﻪ ﺻﻮرت ﻓﺎﮐﺘﻮرﯾﻞ در ﻗﺎﻟﺐ ﻃﺮح ﮐﺎﻣﻼً ﺗﺼﺎدﻓﯽ ﺑﺎ ﭼﻬﺎر ﺗﮑﺮار ﻃﺮاﺣﯽ و اﺟﺮا ﺷﺪ. ﺑﺬور ﺑﻪ ﻣﺪت12 و24 ﺳﺎﻋﺖ در دﻣﺎي 10 و 20 درﺟﻪ ﺳﻠﺴﯿﻮس در ﺳﻪ ﺳﻄﺢ50، 25 و 100 ﻗﺴﻤﺖ در ﻣﯿﻠﯿﻮن ﺟﯿﺒﺮﻟﯿﮏ اﺳﯿﺪ ﺗﯿﻤﺎر ﺷﺪﻧﺪ. اﻋﻤﺎل ﭘﯿﺶﺗﯿﻤﺎر روي ﮐﻠﯿﻪ ﺻﻔﺎت ﻣﻮرد ﺑﺮرﺳﯽ اﺛﺮ ﻣﻌﻨﯽداري داﺷﺖ. ﻏﻠﻈﺖ ﻫﺎي25 و 50 ﻗﺴﻤﺖ در ﻣﯿﻠﯿﻮن ﺟﯿﺒﺮﻟﯿﮏ اﺳﯿﺪ ﺑﻪ ﻋﻨﻮان ﺑﻬﺘﺮﯾﻦ ﭘﯿﺶﺗﯿﻤﺎرﻫﺎ ﺑﻮدﻧﺪ ﮐﻪ ﺗﻮاﻧﺴﺖ درﺻﺪ ﺟﻮاﻧﻪزﻧﯽ ﮐﻞ، درﺻﺪ ﮔﯿﺎﻫﭽﻪﻫﺎي ﺳﺎﻟﻢ و ﺷﺎﺧﺺ ﻃﻮﻟﯽ ﺑﻨﯿﻪ ﮔﯿﺎﻫﭽﻪ را ﺑﻪ ﺷﮑﻞ ﻣﻌﻨﯽداري اﻓﺰاﯾﺶ دﻫﺪ. دﻣﺎي 10 درﺟﻪ ﺳﻠﺴﯿﻮس ﻧﺴﺒﺖ ﺑﻪ 20 درﺟﻪ و ﻣﺪت زﻣﺎن 12 ﺳﺎﻋﺖ ﻧﺴﺒﺖ ﺑﻪ 24 ﺳﺎﻋﺖ ﻧﺘﺎﯾﺞ ﺑﻬﺘﺮي در ﭘﯽ داﺷﺖ و درﺻﺪ ﺟﻮاﻧﻪزﻧﯽ و اﯾﺠﺎد ﮔﯿﺎﻫﭽﻪﻫﺎي ﺳﺎﻟﻢ را ﺑﻪ ﺷﮑﻞ ﻣﻌﻨﯽداري اﻓﺰاﯾﺶ داد. در ﮐﻞ، اﺛﺮات ﻣﻔﯿﺪ ﭘﯿﺶﺗﯿﻤﺎر ﺑﺬر ﺑﺎ ﺟﯿﺒﺮﻟﯿﮏ اﺳﯿﺪ ﺑﺮاي ﺑﻬﺒﻮد ﮐﺎراﯾﯽ ﺟﻮاﻧﻪزﻧﯽ ﺑﺬر ﻋﻠﻒ ﮔﻨﺪﻣﯽ ﺑﻪ وﯾﮋه در ﺷﺮاﯾﻂ ﺗﻨﺶ ﺧﺸﮑﯽ اﺛﺒﺎت ﮔﺮدﯾﺪ.

Seed priming pretreatment improves germination characteristics , seedling establishment and increase of seed performance under environmental stress conditions. This experiment was conducted as factorial based on a completely randomized design with four replications using osmotic potential of -12 bar prepared by polyethylene glycol in order to evaluate the effects of gibberellic acid (GA) pretreatments on the behaviour of seed germination of Agropyron elongatom under drought stress. . Seeds were primed for 12 and 24 hours at two temperatures of 10 and 20°C with GA in three levels of 25, 50 and 100 ppm . All seed pretreatments had significant effect on the whole studied characteristics. Concentration of 25 ppm with GA was the best pretreatment which could increase significantly the whole germination percentage, normal seedling percentage, and length index of seedling vigor.The results obtained in temperature 10 and time duration of 12 were better in comparison to temperature 20 and time duration of 24 and significantly increased the germination and normal seedling percentage. Totally,the useful effects of seed pretreatment method with GA was confirmed for improving the seed germination performance of Agropyron elongatom especially in drought stress condition.