ﺗﺎﺛﯿﺮ ﺗﻨﺶ ﮔﺮﻣﺎ ﺑﺮ ﻣﻮرﻓﻮﻟﻮژي و آﻧﺎﺗﻮﻣﯽ ﺑﺮگ ﮔﯿﺎه ﺟﻮ Hordeum vulgaris رﻗﻢ ﮐﺎرون

The effect of heat stress on morphology and anatomy of leaves of Hordeum vulgaris (cv. Karoun)

ﺗﻨﺶ ﮔﺮﻣﺎ ﯾﮑﯽ از اﺻﻠﯿﺘﺮﯾﻦ ﻋﻮاﻣﻞ ﻣﺤﺪودﮐﻨﻨﺪه ﮐﺸﺖ ﮔﯿﺎﻫﺎن زراﻋﯽ در ﻣﻨﺎﻃﻖ ﮔﺮﻣﺴﯿﺮ ﻣﯿﺒﺎﺷﺪ و ﺳﺎﻟﯿﺎﻧﻪ ﺳﺒﺐ ﺧﺴﺎرات ﺟﺒﺮان ﻧﺎﭘﺬﯾﺮ زﯾﺎدي در ﺻﻨﻌﺖ ﮐﺸﺎورزي ﻣﯽ ﺷﻮد. در ﻣﻄﺎﻟﻌﻪ ﺣﺎﺿﺮ ﺑﻪ ﺑﺮرﺳﯽ اﺛﺮات ﺗﻨﺶ ﮔﺮﻣﺎ ﺑﺮﮔﯿﺎﻫﻤﻬﻤﺰراﻋﯽ ﺟﻮرﻗﻢ ﮐﺎرون ﭘﺮداﺧﺘﻪ ﺷ.ﺪ ﺑﺪﯾﻦ ﻣﻨﻈﻮر ﮔﯿﺎﻫﺎن در ﻣﺮﺣﻠﻪ دو ﺑﺮﮔﯽ ﺑﻪ دو اﺗﺎﻗﮏ رﺷﺪ ﺑﺎ دﻣﺎي 45 درﺟﻪ ﺳﺎﻧﺘﯿﮕﺮاد )ﺗﻨﺶ ﮔﺮﻣﺎ( و 25 درﺟﻪ ﺳﺎﻧﺘﯿﮕﺮاد ﮐﻨﺘﺮل( ﻣﻨﺘﻘﻞ ﺷﺪﻧﺪ. در ﭘﻨﺞ ﻫﻔﺘﻪ ﻣﺘﻮاﻟﯽ ﭘﺎﺳﺦ ﮔﯿﺎﻫﺎن ﺗﺤﺖ ﺗﻨﺶ ﮔﺮﻣﺎ ﺑﺎ ﮔﯿﺎﻫﺎن ﮐﻨﺘﺮل ﻣﻘﺎﯾﺴﻪ ﺷﺪ. ﺗﻨﺶ ﮔﺮﻣﺎ ﺳﺒﺐ ﮐﺎﻫﺶ ﻣﻌﻨﯽ دار ﻃﻮل و وزن ﺧﺸﮏ ﺑﺮگ ﻫﺎ، ﺗﺮاﮐﻢ ﺳﻠﻮﻟﻬﺎي اﭘﯿﺪرﻣﯽ، ﺗﻌﺪاد ﺳﻠﻮل ﻫﺎي روزﻧﻪ در واﺣﺪ ﺳﻄﺢ ﺑﺮگ، و ﻃﻮل و ﻋﺮض ﺳﻠﻮل ﻫﺎي ﻣﺤﺎﻓﻆ روزﻧﻪ اي ﺷ.ﺪ ﺑﯿﺸﺘﺮﯾﻦ ﻣﯿﺰان ﮐﺎﻫﺶ در ﺷﺎﺧﺺ ﻫﺎي ﻣﺬﮐﻮر در ﻫﻔﺘﻪ ﭘﻨﺠﻢ ﺗﻨﺶ ﮔﺮﻣﺎ ﻣﺸﺎﻫﺪه ﺷﺪ. ﺗﻨﺸﻬﺎي ﻏﯿﺮ زﯾﺴﺘﯽ ﺳﺒﺐ اﻓﺰاﯾﺶ ﺗﺠﻤﻊ ﺳﯿﻠﯿﺲ در ﺳﻠﻮﻟﻬﺎي ﺑﺮگ ﻏﻼت ﻣﯽ ﺷﻮﻧﺪ. در ﻣﻄﺎﻟﻌﻪ ﺣﺎﺿﺮ ﻧﯿﺰ ﺗﻨﺶ ﮔﺮﻣﺎ ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﺗﺠﻤﻊ ﺳﯿﻠﯿﺲ در ﺳﻠﻮﻟﻬﺎي ﺑﺮگ ﺷﺪ ﮐﻪ ﺗﻮام ﺑﺎ اﻓﺰاﯾﺶ ﻃﻮل و ﻋﺮض ﺳﻠﻮﻟﻬﺎي ﺳﯿﻠﯿﮑﺎﺑﺎدي ﺷﺪ. ﺑﺮاﺳﺎس ﻧﺘﺎﯾﺞ ﻣﻄﺎﻟﻌﻪ ﺣﺎﺿﺮ، ﺗﻨﺶ ﮔﺮﻣﺎ ﺳﺒﺐ ﮐﺎﻫﺶ رﺷﺪ و ﻋﻤﻠﮑﺮد ﮔﯿﺎه ﺟﻮ در ﻣﻨﺎﻃﻖ ﮔﺮﻣﺴﯿﺮ ﻣﯽ ﺷﻮد.

Heat stress is one of the main limiting factors for crop cultivation in the tropics and causes irreparable damage to the agricultural industry. In the present study, the effects of heat stress on the important crop of barley (Karoon cultivar)was investigated. For this purpose, the plants at two leaves stage were transferred to two different growth chamber with 45 °C(heat stress) and 25 °C(control). During five consecutive weeks, the response of plants under heat stress was compared with control plants. Heat stress significantly decreased leaf length and dry weight, epidermal cell density, number of stomata per leaf area, and length and width of stomatal guard cells. The highest decrease in these featureswas observed in the fifth week of heat stress. Environmental stresses increase the accumulation of silica in leaf cells. The heat stress in the present study increased the accumulation of silica in leaf cells and increased the length and width of silica-bodies. According to the results of this study, heat stress decreases barley growth and yield in tropical regions.