اثر تنش دماي بالا و پايين بر تغييرات رشد، فتوسنتز و فعاليت آنتي‌اكسيداني گوجه‌فرنگي در مرحله رشد رويشي

The Effect of High and Low Temperature Stress on Growth, Photosynthesis and Antioxidant Activity in Vegetative Growth Stage of Tomato

ﻫﺪف از اﯾﻦ آزﻣﺎﯾﺶ ﺑﺮرﺳﯽ اﺛﺮ ﺗﻨﺶ دﻣﺎي ﺑﺎﻻ و ﭘﺎﯾﯿﻦ ﺑﺮ ﺗﻐﯿﯿﺮات رﺷﺪ، ﻓﺘﻮﺳـﻨﺘﺰ و ﻓﻌﺎﻟﯿـﺖ آﻧﺘـﯽ اﮐﺴـﯿﺪاﻧﯽ ﮔﻮﺟﻪ ﻓﺮﻧﮕﯽ در ﻣﺮﺣﻠﻪ رﺷﺪ روﯾﺸﯽ ﺑﻮد. ﮔﯿﺎﻫﺎن رﺷﺪ ﮐﺮده در ﺳﯿﺴﺘﻢ ﻫﯿﺪروﭘﻮﻧﯿﮏ ﺗﺤﺖ ﺗـ ﺄﺛﯿﺮ ﺗـﻨﺶ دﻣـﺎﯾﯽ 40 و 10 درﺟﻪ ﺳﺎﻧﺘﯽ ﮔﺮاد ﺑﻪ ﻣﺪت 24 ﺳﺎﻋﺖ ﻗﺮار ﮔﺮﻓﺘﻨﺪ و ﺑﺎ ﮔﯿﺎﻫﺎن ﺷـﺎﻫﺪ در دﻣـﺎي ﮔﻠﺨﺎﻧـﻪ 25±2 درﺟـﻪ ﺳﺎﻧﺘﯽ ﮔﺮاد ﻣﻘﺎﯾﺴﻪ ﺷﺪﻧﺪ. ﻫﻤﻪ ﮔﯿﺎﻫﺎن ﭘﺲ از اﻋﻤﺎل ﺗﻨﺶ ﺑﻪ ﮔﻠﺨﺎﻧﻪ ﺑﺎ ﺷﺮاﯾﻂ ﺑﻬﯿﻨﻪ ﻣﻨﺘﻘﻞ ﺷﺪﻧﺪ و ﭘﺲ از 10 روز دوﺑﺎره ﻓﺎﮐﺘﻮرﻫﺎي رﺷﺪ ﺑﺮرﺳﯽ ﺷﺪ. ﻧﺘﺎﯾﺞ ﻣﻘﺎﯾﺴﻪ اي ﺑﯿﻦ اﯾﻦ ﺳﻪ دﻣﺎ ﻧﺸﺎن داد ﮐﻪ ﺑﯿﺸﺘﺮﯾﻦ ﻣﯿـﺰان وزن ﺗـﺮ ﺷﺎﺧﺴﺎره در ﺗﯿﻤﺎر ﺷﺎﻫﺪ ﻣﺸﺎﻫﺪه ﺷﺪ. در ﺷﺮاﯾﻂ ﺗﻨﺶ دﻣﺎي ﺑﺎﻻ، 56/7 درﺻﺪ ﮐﺎﻫﺶ وزن ﺗﺮ ﻧﺴﺒﺖ ﺑـﻪ ﺗﯿﻤـﺎر ﺷﺎﻫﺪ و در ﺗﻨﺶ دﻣﺎي ﭘﺎﯾﯿﻦ 65/3 درﺻﺪ ﮐﺎﻫﺶ ﻣﺸﺎﻫﺪه ﺷﺪ. وزن ﺗﺮ رﯾﺸﻪ ﻧﯿﺰ ﺑﻪ ﻃﻮر ﻣﺸﺎﺑﻬﯽ در ﺗﯿﻤﺎر ﺷﺎﻫﺪ ﺑﯿﺸﺘﺮﯾﻦ ﻣﯿﺰان ﺑﻮد و ﺗﻨﺶ ﮔﺮﻣﺎﯾﯽ، 45 درﺻﺪ و ﺗﻨﺶ ﺳﺮﻣﺎﯾﯽ، 64/6 درﺻﺪ ﮐﺎﻫﺶ را ﻧﺴﺒﺖ ﺑﻪ ﺷـﺮاﯾﻂ دﻣـﺎي ﺑﻬﯿﻨﻪ ﻧﺸﺎن داد. ﺣﺠﻢ رﯾﺸﻪ ﺑﺎ اﻋﻤﺎل ﺗـﻨﺶ ﮔﺮﻣـﺎﯾﯽ و ﺳـﺮﻣﺎﯾﯽ ﮐـﺎﻫﺶ ﻣﻌﻨـﯽ داري ﻧﺸـﺎن داد و ﻣﯿـﺰان ﻧـﺮخ ﻓﺘﻮﺳﻨﺘﺰ در ﺷﺮاﯾﻂ ﻣﻌﻤﻮﻟﯽ ﮔﻠﺨﺎﻧﻪ ﺑﯿﺸﺘﺮﯾﻦ ﻣﯿﺰان و در ﺷﺮاﯾﻂ ﺗـﻨﺶ ﮔﺮﻣـﺎﯾﯽ ﮐﻤﺘـﺮﯾﻦ ﻣﯿـﺰان را ﻧﺸـﺎن داد . ﺑﻪ ﻃﻮرﮐﻠﯽ ﻣﯽ ﺗﻮان ﺑﯿﺎن ﮐﺮد ﮐﻪ ﺗﻨﺶ دﻣﺎﯾﯽ در اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺻـﻔﺎت رﺷـﺪي و ﻓﺘﻮﺳـﻨﺘﺰي را ﺑﯿﺸـﺘﺮ از ﺻـﻔﺎت انتي اﮐﺴﯿﺪاﻧﯽ ﺗﺤﺖ ﺗﺄﺛﯿﺮ ﻗﺮار داد.

The aim of this was to investigate the effect of high and low temperature stress on growth, photosynthesis and antioxidant changes in vegetative growth stage of tomato. Tomato plants which were grown in hydroponics system exposed to temperature stress at 40 ºC and 10 ºC compared with plants grown in the greenhouse at optimum temperature of 25±2 as control. All plants were transfer to optimum condition in the greenhouse after stress treatments and growth parameters were measured after 10 days. The results of the comparison between these three temperatures showed that the highest fresh weight of shoot was observed at control treatment. In high temperature stress conditions observed 56.7% decrease fresh weight compared to control treatment and in low temperature stress conditions observed 65.3 decrease. Similarly, fresh weight of root was highest in control treatment and heat stress 45% and low temperature stress 64.6% showed decrease compared to optimum temperature conditions. Root volume was reduced by temperature stress significantly and photosynthesis rate was the highest in control treatment and lowest under high temperature stress. In general, it can be stated that temperature stress in this study affected growth and photosynthetic traits more than antioxidant traits.