ﭘﺎﺳﺦ ﺷﺎﺧﺺ ﻫﺎي ﻣﻮرﻓﻮﻟﻮژي و آﻧﺎﺗﻮﻣﯽ ﮔﯿﺎه ﺟﻮ Hordeum vulgaris رﻗﻢ ﺑﻬﻤﻦ ﺑﻪ ﺗﻨﺶ ﺳﺮﻣﺎ

The response of morphological and anatomical parameters of Hordeum vulgaris (cv. Bahman) to cold stress

ﺗﻨﺶ ﺳﺮﻣﺎ ﯾﮑﯿﺎز ﻣﻬﻢ ﺗﺮﯾﻦ ﺗﻨﺶ ﻫﺎي ﻣﺤﯿﻄﯽ ﻣﺤﺪود ﮐﻨﻨﺪه ﮐﺸﺖ و ﭘﺮورش ﮔﯿﺎﻫﺎن زراﻋﯽ در ﺳﺮﺗﺎﺳﺮ ﺟﻬﺎن ﻣﯽ ﺑﺎﺷﺪ. در ﺗﺤﻘﯿﻖ ﺣﺎﺿﺮ ﺑﻪ ﺑﺮرﺳﯽ ﭘﺎﺳﺦ ﻫﺎﯾﻤﻮﻓﻮﻟﻮژﯾﮑﯽ و آﻧﺎﺗﻮﻣﯿﮑﯽ ﮔﯿﺎه زراﻋﯽ ﺟﻮ ﺑﻪ ﺗﻨﺶ ﺳﺮﻣﺎ )دﻣﺎي 5 درﺟﻪ ﺳﺎﻧﺘﯿﮕﺮاد( ﺑﻪ ﻣﺪت ﭘﻨﺞ ﻫﻔﺘﻪ ﻣﺘﻮاﻟﯽ ﭘﺮداﺧﺘﻪ ﺷﺪ. ﺗﻨﺶ ﺳﺮﻣﺎ ﺳﺒﺐ اﯾﺠﺎد اﺛﺮات ﻣﻀﺮي ﺑﺮ روي اﻧﺪام ﻓﺘﻮﺳﻨﺘﺰ ﮐﻨﻨﺪه ﺑﺮگ ﮔﯿﺎه ﺷﺪ. در ﭘﺎﺳﺦ ﺑﻪ ﺗﻨﺶ ﺳﺮﻣﺎ ﻃﻮل ﺑﺮگ، وزن ﺧﺸﮏ ﺑﺮگ، ﺗﺮاﮐﻢ ﺳﻠﻮل ﻫﺎي اﭘﯿﺪرﻣﯽ ﺑﺮگ، ﺗﺮاﮐﻢ و اﯾﻨﺪﮐﺲ روزﻧﻪ ﻫﺎ، و ﻃﻮل و ﻋﺮض ﺳﻠﻮل ﻫﺎي ﻣﺤﺎﻓﻆ روزﻧﻪ اي ﮐﺎﻫﺶ ﻣﻌﻨﯽ داري را ﻧﺸﺎن دادﻧﺪ. ﺑﯿﺸﺘﺮﯾﻦ ﮐﺎﻫﺶ ﺷﺎﺧﺺ ﻫﺎي ﻣﺬﮐﻮر در ﭘﻨﺠﻤﯿﻦ ﻫﻔﺘﻪ ﺗﻨﺶ ﺳﺮﻣﺎ ﻣﺸﺎﻫﺪه ﺷﺪ. ﺗﻨﺶ ﺳﺮﻣﺎ ﺳﺒﺐ اﻓﺰاﯾﺶ ﺗﺠﻤﻊ ﺳﯿﻠﯿﺲ در ﺳﻠﻮل ﻫﺎي اﭘﯿﺪرﻣﯽ ﺑﺮگ ﺷﺪ ﮐﻪ ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﻣﻌﻨﯽ دار ﻃﻮل و ﻋﺮض ﺳﻠﻮل ﻫﺎي ﺳﯿﻠﯿﮑﺎﺑﺎدي ﺷﺪ. ﺑﺪﯾﻦ ﺗﺮﺗﯿﺐ ﮔﯿﺎه ﺟﻮ ﺑﺎ اﺳﺘﻔﺎده از ﻣﮑﺎﻧﯿﺴﻢ ﺗﺠﻤﻊ ﺳﯿﻠﯿﺲ و اﻓﺰاﯾﺶ ﺳﺎﯾﺰ ﺳﻠﻮل ﻫﺎي ﺳﯿﻠﯿﮑﺎﺑﺎدي ﺑﻪ ﻣﻘﺎﺑﻠﻪ ﺑﺎ ﺗﻨﺶ ﺳﺮﻣﺎ ﭘﺮداﺧﺖ. ﺑﻪ ﻃﻮر ﮐﻠﯽ ﮔﯿﺎه ﺟﻮ ﺑﻪ دﻣﺎي ﭘﺎﯾﯿﻦ ﺣﺴﺎس اﺳﺖ و ﺗﻨﺶ ﺳﺮﻣﺎ ﺑﺎ ﮐﺎﻫﺶ ﺗﻘﺴﯿﻢ ﺳﻠﻮﻟﯽ ﺳﺒﺐ ﮐﺎﻫﺶ رﺷﺪ و ﺗﻘﺴﯿﻢ ﺳﻠﻮل ﻫﺎي ﺑﺮگ ﺷﺪه ﮐﻪ ﺑﺎ ﮐﺎﻫﺶ ﺳﻠﻮل ﻫﺎي اﭘﯿﺪرﻣﯽ و روزﻧﻪ اي و ﮐﺎﻫﺶ رﺷﺪ ﺑﺮگ ﻫﻤﺮاه ﺑﻮد. ﺑﻪ ﻃﻮر ﮐﻠﯽ، ﮐﺸﺖ زود ﻫﻨﮕﺎم ﮔﯿﺎه ﺟﻮ در ﻣﻨﺎﻃﻖ ﺳﺮدﺳﯿﺮ ﺳﺒﺐ ﮐﺎﻫﺶ ﺧﺴﺎرت وارد ﺷﺪه ﺑﻪ اﯾﻦ ﮔﯿﺎه زراﻋﯽ ﻣﯽ ﺷﻮد.

Cold stress is one the most important environmental stress, which limits plant cultivation worldwide. In present research the effect of cold stress (5 ºC) was studied on morphological and anatomical response of barley for 5 continues weeks. Cold stress induced damages into the photosynthetic organ of leaf. In response to cold stress, a significant reduction was observed in the leaf length, leaf dry mass, epidermal cell density, density and index of stomatal complex, and length and width of stomatal guard cells. The highest reduction of them was observed at fifth week of cold stress. Cold stress induced high accumulation of silicon in the leaves epidermal cells, which was accompanied by a significant increase in the length and width of silica-bodies. Accordingly, Barely could apply the silicon accumulation, increase of silica-body cells to reduce the adverse effect of cold stress. In general, early growth of barely in cold regions can reduced the adverse effect of cold stress on this crop.