بررسي كارايي قارچ‌هاي مايكوريز آربوسكولار بر بهبود شاخص‌هاي فيزيولوژيكي پايه ريزافزايي‌شده گلابي (پيرودوارف) زير تنش خشكي

Investigation the Efficiency of Arbuscular Mycorrhizal Fungi on Physiological Indices of Micropropagated Pear Rootstock (Pyrodwarf) under Drought Stress

ﭼﮑﯿﺪهرﯾﺰاﻓﺰاﯾﯽ ﯾﮑﯽ از روشﻫﺎي اﻓﺰاﯾﺶ ﺳﺮﯾﻊ ﮔﯿﺎﻫﺎن در ﻣﺤﯿﻂ ﻏﺬاﯾﯽ اﺳﺖ، اﻣﺎ ﺑﻘﺎ و رﺷﺪ ﺿﻌﯿﻒ اﯾﻦ ﮔﯿﺎﻫﺎن ﭘﺲ از اﻧﺘﻘﺎل، اﺳﺘﻔﺎدەﻩ ﮔﺴﺘﺮده از اﯾﻦ روش را ﻣﺤﺪود ﻣﯽﮐﻨﺪ. ﻣﯿﺰان ﻣﻮﻓﻘﯿﺖ اﯾﻦ روش ﻣﯽﺗﻮاﻧﺪ ﺑﺎ اﺳﺘﻔﺎده از ﻋﺎﻣﻞﻫﺎي زﯾﺴﺘﯽ ﻣﺎﻧﻨﺪ ﻫﻤﺰﯾﺴﺘﯽ ﺑﺎ ﻗﺎرچﻫﺎي ﻣﯿﮑﻮرﯾﺰ آرﺑﻮﺳﮑﻮﻻر اﻓﺰاﯾﺶ ﯾﺎﺑﺪ. ﺑﻪﻣﻨﻈﻮر ﺑﺮرﺳﯽ ﺗﺎﺛﯿﺮ ﻗﺎرچﻫﺎي ﻣﯿﮑﻮرﯾﺰ آرﺑﻮﺳﮑﻮﻻر ﺑﺮ ﺑﻬﺒﻮد ﺷﺎﺧﺺﻫﺎي ﻓﯿﺰﯾﻮﻟﻮژﯾﮑﯽ و ﺗﻨﻈﯿﻢﮐﻨﻨﺪهﻫﺎي اﺳﻤﺰي ﻧﻬﺎلﻫﺎي ﺣﺎﺻﻞ از رﯾﺰازدﯾﺎدي ﮔﻼﺑﯽ ﭘﺎﯾﻪ ﭘﯿﺮودوارف زﯾﺮ ﺗﻨﺶ ﺧﺸﮑﯽ، آزﻣﺎﯾﺸﯽ ﺑﻪﺻﻮرت ﻓﺎﮐﺘﻮرﯾﻞ و در ﻗﺎﻟﺐ ﻃﺮح ﮐﺎﻣﻼ ﺗﺼﺎدﻓﯽ ﺑﺎ دو ﻓﺎﮐﺘﻮر ﺷﺎﻣﻞ دو ﺳﻄﺢ ﻣﯿﮑﻮرﯾﺰا )ﺑﺎ و ﺑﺪون ﻣﯿﮑﻮرﯾﺰا ( و ﺳﻪ ﺳﻄﺢ ﺗﻨﺶ ﺧﺸﮑﯽ )دور آﺑﯿﺎري ﺳﻪ، ﭘﻨﺞ و ﻫﻔﺖ روز ﯾﮏ ﺑﺎر( در ﺳﻪ ﺗﮑﺮار در ﺷﺮاﯾﻂ ﮔﻠﺨﺎﻧﻪاي اﺟﺮا ﺷﺪ. دو ﻣﺎه ﭘﺲ از اﻋﻤﺎل ﺗﻨﺶ ﺧﺸﮑﯽ، ﻧﺘﯿﺠﻪﻫﺎي ﺣﺎﺻﻞ از ﺗﺠﺰﯾﻪ وارﯾﺎﻧﺲ ﻧﺸﺎن داد ﮐﻪ ﻫﻤﺰﯾﺴﺘﯽ ﻣﯿﮑﻮرﯾﺰي ﺑﻪﻃﻮر ﻣﻌﻨﯽداري ﺑﺮ ﺷﺎﺧﺺﻫﺎي ﻓﯿﺰﯾﻮﻟﻮژﯾﮑﯽ و ﺗﻨﻄﯿﻢﮐﻨﻨﺪهﻫﺎي اﺳﻤﺰي ﻣﻮرد ارزﯾﺎﺑﯽ در ﺗﻤﺎﻣﯽ ﺳﻄﻮح ﺗﻨﺶ ﺧﺸﮑﯽ اﺛﺮﮔﺬار ﺑﻮد. ﻣﯿﺰان ﮐﻠﻮﻧﯿﺰاﺳﯿﻮن ﭘﺲ از ﭘﺎﯾﺎن آزﻣﺎﯾﺶ در ﺗﯿﻤﺎرﻫﺎي ﻣﯿﮑﻮرﯾﺰي در ﺳﻄﻮح ﮐﻢ، ﻣﺘﻮﺳﻂ و ﺷﺪﯾﺪ ﺗﻨﺶ ﺧﺸﮑﯽ ﺑﻪﺗﺮﺗﯿﺐ 81/66 ،84 و 72 درﺻﺪ ﺗﻌﯿﯿﻦ ﺷﺪ. ﺑﻪﻃﻮر ﮐﻠﯽ،ﮐﺎرﺑﺮد ﻣﯿﮑﻮرﯾﺰ ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﻣﻌﻨﯽدار ﺷﺎﺧﺺﻫﺎي ﻓﯿﺰﯾﻮﻟﻮژﯾﮑﯽ ﻣﺎﻧﻨﺪ Fv/Fm، ﺷﺎﺧﺺ ﮐﺎراﯾﯽ ﻓﺘﻮﺳﻨﺘﺰ، ﺷﺎﺧﺺ ﺳﺒﺰﯾﻨﮕﯽ )SPAD(، ﻣﺤﺘﻮاي ﮐﻠﺮوﻓﯿﻞ b، ﮐﻠﺮوﻓﯿﻞ ﮐﻞ و ﮐﺎروﺗﻨﻮﺋﯿﺪ و ﻫﻤﭽﻨﯿﻦ ﮐﺎﻫﺶ ﻣﺤﺘﻮاي ﭘﺮوﻟﯿﻦ و ﻗﻨﺪﻫﺎي ﻣﺤﻠﻮل ﺷﺪ. در ﻣﺠﻤﻮع، ﻧﺘﺎﯾﺞ اﯾﻦ آزﻣﺎﯾﺶ ﻧﺸﺎن داد ﮐﻪ ﻧﻬﺎلﻫﺎي ﮐﺸﺖ ﺑﺎﻓﺘﯽ ﺗﯿﻤﺎر ﺷﺪه ﺑﺎ ﻗﺎرچﻫﺎي ﻣﯿﮑﻮرﯾﺰ آرﺑﻮﺳﮑﻮﻻر ﺳﺎزﮔﺎري ﺑﯿﺸﺘﺮي ﺑﺎ ﺷﺮاﯾﻂ ﺑﺮونﺷﯿﺸﻪاي داﺷﺘﻪ و ﺑﺎﻋﺚ اﯾﺠﺎد ﺗﺤﻤﻞ در ﺑﺮاﺑﺮ ﺗﻨﺶ ﺧﺸﮑﯽ ﻣﯽﺷﻮﻧﺪ. .

Micropropagation is a method for mass and rapid proliferation of plants on tissue culture media. Low survival and poor growth of micropropagated seedling after transplanting is one of the main disadvantages of this technique in many plants. The success of this method can be increased by using biological agents such as arbuscular mycorrhizal fungi. The experiment was conducted to evaluate the efficiency of arbuscular mycorrhizal fungi to improve physiological indices and osmotic regulators content of micropropagated pear rootstock (Pyrodwarf) under drought stress. Factorial experiment was performed in a completely randomized design with two factors (two mycorrhizal and three drought stress level). Experiment was conducted in three replications under greenhouse conditions. Drought stress continued for two months. Results of analysis of variance showed that mycorrhizal symbiosis significantly increased physiological parameters and decreased osmotic regulators at all levels of drought stress. Mycorrhizal colonization percentage determined as 84, 81.66 and 72%, in low, medium and severe drought stresses levels, respectively. Mycorrhizal application significantly increased physiological indices such as Fv/Fm, photosynthetic efficiency index, SPAD index, and the content of chlorophyll b, cartenoid and total chlorophyll in mycorrhizal treatments compared to control (no mycorrhizal plants) and decreased proline and soluble sugars content. Overall, the results of this experiment showed that rootstocks obtained from tissue culture treated with arbuscular mycorrhizal fungi were more adapted to natural conditions and drought stress.