ﺑﺮرﺳﯽ ﺗﻐﯿﯿﺮات اﻟﮕﻮي اﺳﯿﺪﻫﺎي ﭼﺮب ذرت رﻗﻢ 480 ﺳﯿﻨﮕﻞ ﮐﺮاس ﺗﺤﺖ ﺗﺎﺛﯿﺮ ﺳﺮﻣﺎ

Investigation of the fatty acid changes occurred in single-cross 480 maize cultivar under cold stress

ذرت ﺑﻪ ﻋﻨﻮان ﯾﮑﯽ از ﻣﻨﺎﺑﻊ اﺻﻠﯽ ﺗﺎﻣﯿﻦ اﻧﺮژي در ﺗﻐﺬﯾﻪ اﻧﺴﺎن و دام از اﻫﻤﯿﺖ وﯾﮋه اي ﺑﺮﺧﻮردار ﻣﯽ ﺑﺎﺷﺪ. ﺑﺎ اﯾﻦ ﺣﺎل ﻫﻤﺎﻧﻨﺪ دﯾﮕﺮ ﮔﯿﺎﻫﺎن زراﻋﯽ، ﮔﯿﺎه ذرت ﻧﯿﺰ ﻫﻤﻮاره در ﻣﻮاﺟﻬﻪ ﺑﺎ ﺗﻨﺶ ﻫﺎي زﯾﺴﺘﯽ و ﻏﯿﺮزﯾﺴﺘﯽ اﺳ.ﺖ ﺗﻨﺶ ﺳﺮﻣﺎ ﯾﮑﯽ از ﻋﻮاﻣﻞ ﻣﺤﺪودﮐﻨﻨﺪه ﮐﺸﺖ ذرت در ﺑﺮﺧﯽ از ﻧﻘﺎط اﯾﺮان ﻣﯽ ﺑﺎﺷ.ﺪ در اﯾﻦ ﻣﻄﺎﻟﻌﻪ، ﺑﺬور ذرت ﺳﯿﻨﮕﻞ ﮐﺮاس رﻗﻢ 480 ﮐﺸﺖ ﺷﺪه و ﭘﺲ از رﺳﯿﺪن ﺑﻪ ﻣﺮﺣﻠﻪ ﺳﻪ ﺑﺮﮔﯽ، در دﻣﺎي C10 ﻗﺮار ﮔﺮﻓﺘﻨ.ﺪ ﻧﻤﻮﻧﻪ ﺑﺮداري از ﮔﯿﺎﻫﺎن ﺗﯿﻤﺎرﺷﺪه در دو ﻣﺮﺣﻠﻪ 24و 48 ﺳﺎﻋﺖ ﭘﺲ از اﻋﻤﺎل ﺗﯿﻤﺎر اﻧﺠﺎم ﺷ.ﺪ ﭘﺲ از آﻣﺎده ﺳﺎزي ﻧﻤﻮﻧﻪ ﻫﺎ، از روش GC-MS ﺑﺮاي ﺑﺮرﺳﯽ ﻣﻘﺪار اﺳﯿﺪﻫﺎي ﭼﺮب اﺳﺘﻔﺎده ﺷ.ﺪ ﻧﺘﺎﯾﺞ ﺑﻪ دﺳﺖ آﻣﺪه در اﯾﻦ آزﻣﺎﯾﺶ ﻧﺸﺎن داد ﮐﻪ ﺗﻨﺶ ﺳﺮﻣﺎ ﺳﺒﺐ اﻓﺰاﯾﺶ ﺑﺮﺧﯽ از اﺳﯿﺪﻫﺎي ﭼﺮب در ذرت ﻣﯽ ﺷﻮد. اﺳﯿﺪﻫﺎي ﭼﺮب C23:0 C18:3n6 C182n6t C18:1n9t C18:0 C15:1 اﻓﺰاﯾﺶ ﻣﻌﻨﯽ داري در ﺷﺮاﯾﻂ ﺗﻨﺶ ﺳﺮﻣﺎ ﻧﺴﺒﺖ ﺑﻪ ﮔﯿﺎﻫﺎن ﺷﺎﻫﺪ ﻧﺸﺎن دادﻧﺪ. اﻓﺰاﯾﺶ ﻣﻘﺪار اﺳﯿﺪﻫﺎي ﭼﺮب ﻏﯿﺮاﺷﺒﺎع ﺑﻪ ﺧﺼﻮص اﺳﯿﺪ ﻟﯿﻨﻮﻟﺌﯿﮏ ﺑﻪ ﻋﻨﻮان ﺷﺎﺧﺺ ﻣﺜﺒﺖ در ارزﯾﺎﺑﯽ ذرت ﻣﻘﺎوم ﺑﻪ ﺳﺮﻣﺎ ﻣﻄﺮح ﻣﯽ ﺑﺎﺷﺪ.

Maze is one of the most important energy recourses for human and poultry nutrition. Nonetheless, likewise other corps, maize is always exposed to biotic and abiotic stresses, which decrease its production. Low temperature, is considered as one of the limiting factors influencing corn cultivation in some parts of Iran. Therefore, introducing a hybrid maize with acceptable characteristics could play a vital role in response to cold stress, and consequently yield enhancement. Thus, herein, the seeds of single cross 480 cultivar were cultivated and after reaching triple-leaf stage, they were incubated at 10oC. The plant materials were then harvested at two stages; 24 and 48 h after treatment. Afterward, the samples were prepared and subjected to GC-MS so as to measure the amount of fatty acids. The results showed that cold stress increased the accumulation of some fatty acids in treated plants. Of which, C15: 1, C18: 0, C18: 1n9t, C182n6t, C18: 3n6, and C23: 0 fatty acids demonstrated significant increase in sold stress conditions as compared with control plants. The higher accumulation of the unsaturated fatty acids, especially linoleic acid, is a desired factor in evaluation of cold resistant maize.