ﺗﺄﺛﻴﺮ ﻣﺘﻴﻞ ﺟﺎﺳﻤﻮﻧﺎت ﺑﺮ رﺷﺪ و ﻣﻘﺪار اﺳﺎﻧﺲ ﻣﺮزﻧﺠﻮش )Origanum majorana L.( در ﺷﺮاﻳﻂ ﺗﻨﺶ ﺧﺸﻜﻲ

Effect of methyl jasmonate on growth and essential oil content of marjoram (Origanum majorana L.) under drought stress conditions

ﻣﺮزﻧﺠﻮش Origanum majorana L)( از ﺧﺎﻧﻮاده ﻧﻌﻨﺎﻳﻴﺎن ﻣﻲ ﺑﺎﺷﺪ. ﺗﻨﺶ ﺧﺸﻜﻲ ﺑﺎﻋﺚ ﻣﺤﺪود ﺷﺪن رﺷﺪ ﮔﻴﺎﻫﺎن داروﻳﻲ ازﺟﻤﻠﻪ ﻣﺮزﻧﺠﻮش ﻣﻲ ﺷﻮد. دراﻳﻦ ﺑﺮرﺳﻲ، واﻛﻨﺶ ﻣﺮزﻧﺠﻮش ﺑﻪ ﻣﺘﻴﻞ ﺟﺎﺳﻤﻮﻧﺎت )ﻏﻠﻈﺖ ﻫﺎي 0 و 100 ﻣﻴﻜﺮوﻣﻮﻻر( در ﺷﺮاﻳﻂ ﺗﻨﺶ ﺧﺸﻜﻲ )رﻃﻮﺑﺖ ﺧﺎك ﻣﻌﺎدل 50 درﺻﺪ )ﺗﻨﺶ ﻣﺘﻮﺳﻂ(، 75 درﺻﺪ )ﺗﻨﺶ ﻣﻼﻳﻢ( و 100 درﺻﺪ )ﺑﺪون ﺗﻨﺶ( ﻇﺮﻓﻴﺖ زراﻋﻲ( ﻣﻮرد ارزﻳﺎﺑﻲ ﻗﺮار ﮔﺮﻓﺖ. ﺑﺮاﺳﺎس ﻧﺘﺎﻳﺞ ﺑﺪﺳﺖ آﻣﺪه، ﺗﺄﺛﻴﺮ ﺳﻄﻮح ﻣﺨﺘﻠﻒ ﺗﻨﺶ ﺧﺸﻜﻲ ﺑﺮ وزن ﺗﺮ و ﺧﺸﻚ، ارﺗﻔﺎع ﺑﻮﺗﻪ،ﻣﻴﺰان ﻛﻠﺮوﻓﻴﻞ b، ﻛﻠﺮوﻓﻴﻞ ﻛﻞ، ﻛﺎروﺗﻨﻮﺋﻴﺪ، ﻓﻌﺎﻟﻴﺖ آﻧﺰﻳﻢ ﻛﺎﺗﺎﻻز و ﻗﻨﺪ ﻣﺤﻠﻮل ﻣﻌﻨﻲ دار ﮔﺮدﻳﺪ. ﺗﻨﺶ ﻣﺘﻮﺳﻂ ﻣﻮﺟﺐ ﻛﺎﻫﺶ ﻛﻠﺮوﻓﻴﻞ ﻛﻞ و اﻓﺰاﻳﺶ ﻣﻴﺰان ﻛﺎروﺗﻨﻮﺋﻴﺪ، آﻧﺰﻳﻢ ﻛﺎﺗﺎﻻز و ﻗﻨﺪ ﻣﺤﻠﻮل ﺑﻪ ﺗﺮﺗﻴﺐ ﺑﻪ ﻣﻴﺰان 15/52، 38/25، 79/63 و 42/86 درﺻﺪ در ﻣﻘﺎﻳﺴﻪ ﺑﺎ ﺷﺎﻫﺪ ﮔﺮدﻳﺪ. اﻓﺰاﻳﺶ درﺻﺪ اﺳﺎﻧﺲ ﺣﺎﺻﻞ از ﺑﺮگ ﮔﻴﺎه در ﺷﺮاﻳﻂ ﺗﻨﺶ ﺧﺸﻜﻲ ﻣﻌﻨﻲ دار ﻧﺒﻮد. ﻣﺤﻠﻮل ﭘﺎﺷﻲ ﻣﺘﻴﻞ ﺟﺎﺳﻤﻮﻧﺎت ﻣﻮﺟﺐ اﻓﺰاﻳﺶ ﻛﻠﺮﻓﻴﻞ b ،a، ﻛﻠﺮوﻓﻴﻞ ﻛﻞ، ﻓﻌﺎﻟﻴﺖ آﻧﺰﻳﻢ ﻛﺎﺗﺎﻻز و ﻗﻨﺪﻣﺤﻠﻮل ﺑﻪ وﻳﮋه در ﺷﺮاﻳﻂ ﺑﺪون ﺗﻨﺶ و ﺗﻨﺶ ﻣﺘﻮﺳﻂ ﮔﺮدﻳﺪ. ﻧﺘﺎﻳﺞ ﻧﺸﺎن داد ﻛﻪ ﻣﺘﻴﻞ - ﺟﺎﺳﻤﻮﻧﺎت ﺿﻤﻦ اﻓﺰاﻳﺶ ﻣﻴﺰان ﻓﻌﺎﻟﻴﺖ آﻧﺰﻳﻢ ﻛﺎﺗﺎﻻز و ﻣﻘﺪار ﻗﻨﺪ ﻣﺤﻠﻮل ﮔﻴﺎه ﺑﻪ ﻧﺤﻮي از ﻓﻌﺎﻟﻴﺖ رادﻳﻜﺎل ﻫﺎي آزاد ﺗﺤﺖ ﺗﻨﺶ ﻣﺘﻮﺳﻂ ﺟﻠﻮﮔﻴﺮي ﻛﺮده و ﺑﻪ اﻳﻦ ﺗﺮﺗﻴﺐ ﺑﻘﺎي ﺑﻴﺸﺘﺮ ﮔﻴﺎه را ﺗﻀﻤﻴﻦ ﻣﻲ ﻧﻤﺎﻳﺪ. ﺑﻄﻮرﻛﻠﻲ ﻧﺘﺎﻳﺞ ﺣﺎﺻﻞ از اﻳﻦ آزﻣﺎﻳﺶ ﻧﺸﺎن داد ﻛﻪ اﺳﺘﻔﺎده از ﻣﺘﻴﻞ ﺟﺎﺳﻤﻮﻧﺎت ﻣﻲ ﺗﻮاﻧﺪ راﻫﻜﺎري ﻣﻨﺎﺳﺐ ﺑﺮاي ﻣﻘﺎﺑﻠﻪ ﺑﺎ ﺷﺮاﻳﻂ ﺗﻨﺶ ﺧﺸﻜﻲ در ﮔﻴﺎه ﻣﺮزﻧﺠﻮش ﺑﺎﺷﺪ.

Marjoram (Origanum majorana L.) is one of the plants of Labiatae family. Drought stress limits the growth of medicinal plants, including marjoram. In this study, response of marjoram to foliar methyl jasmonate application (with concentrations 0, 100 μM) under drought stress (soil moisture equivalent to 50 (moderate stress), 75 (mild stress) and 100% of field capacity (without stress)) was evaluated. Based on the results obtained in this study the effect of different levels of drought stress on plant fresh and dry weight, plant height, chlorophyll b, total chlorophyll and carotenoids content, catalase activity and soluble sugar content was significant. When compared to control, moderate stress reduced chlorophyll and increased carotenoids, catalase activity and soluble sugar content 15.52, 38.25, 79.63 and 42.86% respectively. Essential oil percentage, which obtained from plant leaves under drought stress, did not change significantly. Application of methyl jasmonate increased chlorophyll a, b and total, catalase activity and soluble sugar, particularly in non- stress and severe stress conditions. These results showed that methyl jasmonate could increase catalase activity and soluble sugar content while under drought stress condition inhibit the activity of free radicals and thus ensures survival of the marjoram plants. In general, the results of this experiment showed that the use of mthyl jasmonate could appropriate way to cope with drought in marjoram.