تأثير عصاره جلبك سارگاسوم (Sargassum angustifolium C.Agardh) بر ميزان وزن خشك، ارتفاع گياه و توليد پرولين در گياه كلزا (Brassica napus L.) تحت تنش خشكي

Effect of a seaweed,Sargassum angustifoliumC.Agardh, extract on dry weight, plant height and proline content in rapeseed (Brassica napus L.) under drought stress

ﺗﻨﺶﻫﺎي ﻣﺤﯿﻄﯽ ﻏﯿﺮ زﻧﺪه، ﺑﻪ وﯾﮋه ﺗﻨﺶ ﺧﺸﮑﯽ، ﯾﮑﯽ از ﻣﻬﻤﺘﺮﯾﻦ ﻣﺸﮑﻼت ﻣﻨﺎﻃﻖ ﺧﺸﮏ و ﻧﯿﻤﻪ ﺧﺸﮏ ﺟﻬﺎن اﺳﺖ. ﺑﻨﻈﺮ ﻣﯽ-رﺳﺪ ﮐﻪ اﺳﺘﻔﺎده از ﻋﺼﺎرهي ﺟﻠﺒﮏ، روﺷﯽ ﻣﺆﺛﺮ و ﻣﻘﺮون ﺑﻪ ﺻﺮﻓﻪ ﺑﺮاي ﺑﻬﺒﻮد ﺑﻪ ﺗﺤﻤﻞ ﺧﺸﮑﯽ در ﻣﺤﺼﻮﻻت زراﻋﯽ اﺳﺖ. در اﯾﻦ ﺗﺤﻘﯿﻖ ﺑﻪ ﻣﻨﻈﻮر ﺑﺮرﺳﯽ ﺗﺄﺛﯿﺮ ﻋﺼﺎره ﺟﻠﺒﮏ ﺑﺮ ﺑﻬﺒﻮد ﺗﺤﻤﻞ ﮔﯿﺎه ﮐﻠﺰا ﺑﻪ ﺗﻨﺶ ﺧﺸﮑﯽ،آزﻣﺎﯾﺶ ﻓﺎﮐﺘﻮرﯾﻞ در ﻗﺎﻟﺐ ﻃﺮح ﮐﺎﻣﻼ ً ﺗﺼﺎدﻓﯽ )دو ﺳﻄﺢ ﻋﺼﺎره ﺟﻠﺒﮏ و ﺳﻪ ﺳﻄﺢ ﺧﺸﮑﯽ ﺑﺎ 3 ﺗﮑﺮار( اﻧﺠﺎم ﺷﺪ. ﺗﺎ اﻧﺘﻬﺎي آزﻣﺎﯾﺶ، ﮔﯿﺎﻫﭽﻪﻫيﺎ ﺷﺎﻫﺪ ﺑﺎ آب ﻣﻘﻄﺮ اﺳﺘﺮﯾﻞ و ﮔﯿﺎﻫﭽﻪﻫﺎي ﺗﯿﻤﺎر ﺑﺎ ﻋﺼﺎره ﺟﻠﺒﮏ درﯾﺎﯾﯽ ﺑﺎ ﻏﻠﻈﺖ 1/100 ﻫﺮ 3 روز ﯾﮑﺒﺎر اﺳﭙﺮي ﺷﺪﻧﺪ. ﭘﺲ از اﯾﻨﮑﻪ ﮔﯿﺎﻫﭽﻪﻫﺎ ﺑﻪ ﻣﺮﺣﻠﻪ 7 ﺑﺮﮔﯽ رﺳﯿﺪﻧﺪ، ﺗﻨﺶ ﺧﺸﮑﯽ در ﺳﻪ ﺳﻄﺢ80% ﻇﺮﻓﯿﺖ ﻣﺰرﻋﻪ ﺑﻪ ﻣﺪت 20 روز )ﻓﺎز اول( ، %60ﻇﺮﻓﯿﺖ ﻣﺰرﻋﻪ ﺑﻪ ﻣﺪت 20 روز )ﻓﺎز دوم( و 40% ﻇﺮﻓﯿﺖ ﻣﺰرﻋﻪ ﺑﺮاي 20 روز )ﻓﺎز ﺳﻮم( اﻋﻤﺎل ﺷﺪ و ﻣﯿﺰان وزن ﺧﺸﮏ، ارﺗﻔﺎع ﮔﯿﺎه و ﻣﺤﺘﻮاي ﭘﺮوﻟﯿﻦ اﻧﺪازهﮔﯿﺮي ﺷﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﺗﯿﻤﺎر ﺟﻠﺒﮏ درﯾﺎﯾﯽ ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﻣﻌﻨﯽداري در ارﺗﻔﺎع ﺷﺎﺧﺴﺎره و وزن ﺧﺸﮏ ﻧﺴﺒﺖ ﺑﻪ ﺷﺎﻫﺪ ﺷﺪه اﺳﺖ. ﻋﻼوه ﺑﺮ اﯾﻦ، ﻣﯿﺰان ﭘﺮوﻟﯿﻦ در ﺑﺎﻓﺖﻫﺎي ﮔﯿﺎﻫﯽ ﺗﺤﺖ ﺗﯿﻤﺎر ﺑﺎ ﻋﺼﺎرهي ﺟﻠﺒﮏ درﯾﺎﯾﯽ ﺑﻄﻮر ﻣﻌﻨﯽداري اﻓﺰاﯾﺶ ﯾﺎﻓﺖ. ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از اﯾﻦ ﭘﮋوﻫﺶ اﺳﺘﻔﺎده ازﻋﺼﺎرهي ﺟﻠﺒﮏ درﯾﺎﯾﯽ را ﺑﻪ ﻣﻨﻈﻮر ﺑﻬﺒﻮد ﺗﺤﻤﻞ ﮔﯿﺎه ﮐﻠﺰا ﺑﻪ ﺗﻨﺶ ﺧﺸﮑﯽ، ﭘﯿﺸﻨﻬﺎد ﻣﯽﮐﻨﺪ.

Abiotic environmental stresses, especially drought, are one of the most important problems in arid and semi-arid regions of the world. Application of algae extract seems to be an efficient and cost-effective way to improve drought tolerance in crops. In this study, a factorial experiment was conducted in a completely randomized design (two levels of algae extract and three levels of drought with 3 replications) to improve the tolerance of rapeseed to drought stress. By the end of the experiment, the control seedlings were sprayed with sterile distilled water and the seedlings treated with seaweed extract at a concentration of one in every three days. After seedlings reached the 7-leaf stage, drought stress at three levels including 80% of field capacity (FC) for 20 days (phase I), 60% of FC for 20 days (phase II) and 40% of FC for 20 days (phase III) was induced. Then, dry weight, plant height and proline content of the plants were measured. Results showed that seaweed treatments significantly increased the plant shoot height and dry weight compared to control. In addition, proline content was significantly increased in plant tissues treated with seaweed extract. The results of this research suggests the use of algae extract to improve drought tolerance in rapeseed