ﺑﺮﻫﻤﻜﻨﺶ ﺷﻮري و ﺟﻴﺒﺮﻟﻴﻦ ﺑﺮ رﻳﺰش ﺑﺮگ، ﻣﺎده ﺧﺸﻚ، ﻓﻌﺎﻟﻴﺖ آﻧﺰﻳﻢﻫﺎي آﻧﺘﻲ-اﻛﺴﻴﺪان و ﻣﺤﺘﻮاي ﻋﻨﺎﺻﺮ در ﮔﻮاوا )Psidium guajava L.(

The interaction of salinity and gibberellin on leaf abscission, dry matter, antioxidant enzymes activity and ion content in guava (Psidium guajava L)

ﻣﻴﻮه ﮔﻮاوا ﻣﻨﺒﻊ ﺑﺴﻴﺎر ﻏﻨﻲ از وﻳﺘﺎﻣﻴﻦ ث، ﺑﺎ اﻣﻜﺎن دوﺑﺎر ﻣﻴﻮهدﻫﻲ در ﺳﺎل و ﻋﻤﻠﻜﺮد ﺑﺎﻻ، درآﻣﺪ ﻗﺎﺑﻞﺗﻮﺟﻬﻲ را ﺑﺮاي ﺗﻮﻟﻴﺪ-ﻛﻨﻨﺪﮔﺎن ﺑﻪ ارﻣﻐﺎن ﻣﻲآورد. اﻣﺎ ازآﻧﺠﺎ ﻛﻪ ﻋﻤﺪه ﻣﻨﺎﻃﻖ ﮔﺮﻣﺴﻴﺮ ﻛﺸﻮر ﺑﺎ ﻣﻌﻀﻞ ﺷﻮري آب ﻣﻮاﺟﻪ ﻫﺴﺘﻨﺪ، ﻛﺸﺖ اﻳﻦ ﮔﻴﺎه در ﻣﻨﺎﻃﻖ ﻣﺬﻛﻮر ﻣﻲﺗﻮاﻧﺪ ﻋﻤﻠﻜﺮد و ﻛﻴﻔﻴﺖ ﻣﺤﺼﻮل را ﺗﺤﺖ ﺗﺎﺛﻴﺮ ﻗﺮار دﻫﺪ. از ﻃﺮﻓﻲ ﻣﺤﻠﻮل ﭘﺎﺷﻲ ﮔﻴﺎﻫﺎن ﺑﺎ ﺟﻴﺒﺮﻟﻴﻚاﺳﻴﺪ، در ﺑﻬﺒﻮد ﺧﺴﺎرت وارده از ﺗﻨﺶ ﺷﻮري ﻣﻮﺛﺮ ﺑﻮده اﺳﺖ. ﻟﺬا در اﻳﻦ ﺗﺤﻘﻴﻖ ﻣﻴﺰان رﻳﺰش ﺑﺮگ، ﻣﺎده ﺧﺸﻚ، آﻧﺰﻳﻢﻫﺎي آﻧﺘﻲاﻛﺴﻴﺪان و ﻣﺤﺘﻮاي ﻋﻨﺎﺻﺮ در ﻧﻬﺎلﻫﺎي ﺑﺬري ﮔﻮاوا، ﺗﺤﺖ ﺗﺎﺛﻴﺮ ﺳﻄﻮح ﻣﺨﺘﻠﻒ ﻛﻠﺮﻳﺪﺳﺪﻳﻢ )1/7، 3 و 6 دﺳﻲزﻳﻤﻨﺲ ﺑﺮ ﻣﺘﺮ( و ﺟﻴﺒﺮﻟﻴﻚ-اﺳﻴﺪ )0، 250 و 500 ﭘﻲﭘﻲام( ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﻗﺮار ﮔﺮﻓﺖ. ﺑﻨﺎ ﺑﻪ ﻧﺘﺎﻳﺞ ﺑﺎ اﻓﺰاﻳﺶ ﺳﻄﻮح ﺷﻮري از 3 ﺗﺎ 6 دﺳﻲزﻳﻤﻨﺲ ﺑﺮ ﻣﺘﺮ، ﺑﺮ ﻣﻴﺰان ﻛﻠﺮ و ﻧﺴﺒﺖ ﻛﻠﺴﻴﻢ ﺑﻪ ﻣﺠﻤﻮع ﺳﺪﻳﻢ و ﭘﺘﺎﺳﻴﻢ، ﻧﺴﺒﺖ ﺳﺪﻳﻢ ﺑﻪ ﭘﺘﺎﺳﻴﻢ، ﻧﺴﺒﺖ ﻛﻠﺴﻴﻢ ﺑﻪ ﻣﻨﻴﺰﻳﻢ و ﻧﺴﺒﺖ ﺳﺪﻳﻢ ﺑﻪ ﻛﻠﺴﻴﻢ در ﺑﺮگ و رﻳﺸﻪ اﻓﺰوده و از ﺗﻌﺪاد ﺑﺮگ و ﻣﺎده ﺧﺸﻚ ﻛﺎﺳﺘﻪ ﺷﺪ. ﻫﻤﭽﻨﻴﻦ ﺷﻮري ﺑﺎﻋﺚ ﻛﺎﻫﺶ در ﻣﻴﺰان ﻓﻌﺎﻟﻴﺖ آﻧﺰﻳﻢﻫﺎي ﭘﺮاﻛﺴﻴﺪاز و ﭘﻠﻲﻓﻨﻞاﻛﺴﻴﺪاز و اﻓﺰاﻳﺶ در ﻓﻌﺎﻟﻴﺖ ﻛﺎﺗﺎﻻز ﮔﺮدﻳﺪ. ﺑﻴﺸﺘﺮﻳﻦ ﻣﻴﺰان ﺳﺪﻳﻢ و ﻛﻤﺘﺮﻳﻦ ﻣﻴﺰان ﭘﺘﺎﺳﻴﻢ در ﺗﻴﻤﺎر ﺷﻮري 6 دﺳﻲ- زﻳﻤﻨﺲ ﺑﺮ ﻣﺘﺮ ﻣﺸﺎﻫﺪه ﺷﺪ. ﻣﺤﻠﻮلﭘﺎﺷﻲ ﺷﺎﺧﺴﺎره ﺑﺎ ﺟﻴﺒﺮﻟﻴﻚاﺳﻴﺪ ﺗﺤﺖ ﺗﻨﺶ ﺷﻮري، ﺑﺎ اﻓﺰاﻳﺶ ﻣﻴﺰان ﭘﺘﺎﺳﻴﻢ و ﻧﺴﺒﺖ ﭘﺘﺎﺳﻴﻢ ﺑﻪ ﺳﺪﻳﻢ، ﺗﻮزﻳﻊ ﺑﻬﺘﺮ ﻛﻠﺴﻴﻢ و ﻛﺎﻫﺶ رﻳﺰش ﺑﺮگ ﻫﻤﺮاه ﺑﻮد و ﺑﻪ ﻋﻨﻮان راﻫﻜﺎري ﻣﻮﺛﺮ در ﺗﺨﻔﻴﻒ ﺧﺴﺎرت وارده از ﺗﻨﺶ ﺷﻮري ﺑﺮ ﻧﻬﺎل ﮔﻮاوا ﻣﻌﺮﻓﻲ ﻣﻲ ﮔﺮدد.

Guava is a rich source of vitamin C, with double-fruiting thorough a year and high yield, has considerable income to have delivered for the producer. But since the major tropical regions faced with the saline water, cultivating of this plant in such areas can affect the yield and the quality of the product. Therefore, in this research leaf abscission, dry matter, antioxidant enzymes activity and elemental content in Guava seedlings, under sodium chloride concentrations (1.7, 3 and 6 dSm-1) and gibberellic acid application (0, 250 and 500 ppm) was studied. According to results salt rising from 3 to 6 dSm-1, increased the chlorine, Ca/(Na+K), Na/K, Ca/Mg and Na/Ca in leaves and roots and reduced leave number and dry matter. salinity reduced the peroxidase and polyphenol oxidase activity, wherease it increased the catalase activity. The most sodium and the least potassium was observed under 6 dSm-1 salinity. Foliar gibberellic acid (500 ppm) application under salt condition, decreased leaf abscission and increased K, and K/Na as well as Ca content, which can be introduced as an effective approach to reduce the damages which caused by salinity stress on guava seedlings.