ﺑﺮرﺳﻲ تاثیر ﺗﻨﺶ ﺷﻮری و ﺧﺸﻜﻲ ﺑﺮ ﺧﺼﻮﺻﻴﺎت جوانه‌زﻧﻲ و رﺷﺪ ﮔﻴﺎﻫﭽﻪ تلخ بیان (sophora pachycarpa schrenk ex c.a.mey)

ﺑﻪ‌ﻣﻨﻈﻮر ﺑﺮرﺳﻲ اثر غلظت های ﻣﺨﺘﻠﻒ ﻛﻠﺮﻳﺪ سدیم و ﭘﻠﻲاﺗﻴﻠﻦ ﮔﻼﻳﻜﻮل در ﻣﺮاﺣﻞ جوانه زنی و رﺷﺪ ﮔﻴﺎﻫﭽﻪ تلخ بیان (sophora pachycarpa schrenk ex c.a.mey) آزمایشی در ﻗﺎﻟﺐ ﻃﺮح ﻛﺎﻣﻼً ﺗﺼﺎدﻓﻲ ﺑﺎ چهار تکرار در آزمایشگاه تحقیقاتی داﻧﺸﻜﺪه ﻛﺸﺎورزی داﻧﺸﮕﺎه فردوسی مشهد در سال 1397 اﻧﺠﺎم ﺷﺪ. ﺗﻴﻤﺎرﻫﺎی آزﻣﺎﻳﺶ ﺷﺎﻣﻞ ﺳﻄﻮح ﻣﺨﺘﻠﻒ پتانسیل اسمزی و ماتریک ناشی از تنش شوری و خشکی در نه سطح (0 ، 0.1- ، 0.2- ، 0.4- ، 0.8- ، 1- ، 1.2- ، 1.4- و 1.5- مگاپاسگال) ﺑﻮدﻧﺪ. ﻧﺘﺎﻳﺞ ﻧﺸﺎن داد ﻛﻪ ﺑﺎ اﻓﺰاﻳﺶ ﺷﺪت ﺗﻨﺶ ﺷﻮری و ﺧﺸﻜﻲ ﺑﻪ‌ﺻﻮرت معنی داری از درﺻﺪ و ﺳﺮﻋﺖ ﺟﻮاﻧﻪزﻧﻲ، ﻃﻮل ریشه چه و ساقه چه، وزن تر گیاهچه، ریشه چه و ساقه چه تلخ بیان کاسته شد (p≤01.0). ﺑﺎ اﻓﺰاﻳﺶ ﺷﺪت ﺗﻨﺶ شوری و خشکی از 0.1- به 1.5- مگاپاسگال، درﺻﺪ ﺟﻮاﻧه زﻧﻲ 100 درصد نسبت به شاهد کاهش یافت و اﻳﻦ ﻛﺎﻫﺶ در ﺗﻨﺶ ﺧﺸﻜﻲ ﺑﻪ‌ﻃﻮر معنی‌داری در اﻛﺜﺮ ﺻﻔﺎت ﻧﺴﺒﺖ ﺑﻪ ﺗﻨﺶ شوری بیشتر بود. کاهش طول ساقه چه در ﻫﺮ دو ﺗﻨﺶ ﺑﻴﺸﺘﺮ از رﻳﺸه چه ﺑﻮد ﻛﻪ ﻧﺸﺎن‌دﻫﻨﺪه ﺣﺴﺎﺳﻴﺖ ﺑﻴﺸﺘﺮ اﻳﻦ ﺻﻔﺖ ﻣﻲﺑﺎﺷﺪ. برازش مدل سیگموئیدی سه پارامتری، راﺑﻄﻪ ﺑﻴﻦ ﺳﻄﻮح ﻣﺨﺘﻠﻒ ﺗﻨﺶ شوری و خشکی را ﺑﺎ درﺻﺪ ﺟﻮاﻧﻪزﻧﻲ به‌خوبی ﺗﻮﺟﻴﻪ ﻧﻤﻮد. ﭘﺎراﻣﺘﺮ x50 ﻣﺪل ﻧﺸﺎن داد ﻛﻪ ﺗﻨﺶ ﺷﻮری و ﺧﺸﻜﻲ ﺑﻪ‌ﺗﺮﺗﻴﺐ در ﭘﺘﺎﻧﺴﻴل های 1.08- و 0.43- مگاپاسگال ﻣﻨﺠﺮ ﺑﻪ ﻛﺎﻫﺶ 50 درﺻﺪی ﺣﺪاﻛﺜﺮ ﺟﻮاﻧﻪزﻧﻲ ﺷﺪﻧﺪ ﻛﻪ ﻧﺸﺎن‌دﻫﻨﺪه ﺗﺄﺛﻴﺮ ﺑﻴﺸﺘﺮ ﺗﻨﺶ ﺧﺸﻜﻲ ﺑﺮ تلخ بیان می باﺷﺪ و وجود تنش های شوری و خشکی می تواند باعث ﻛﺎﻫﺶ ﺷﺎﺧص‌های رﺷﺪی اﻳﻦ ﻋﻠﻒ ﻫﺮز در ﻣﺮاﺣﻞ ﺟﻮانه زنی و گیاهچه ای شود.

effect of salinity and drought stress on germination characteristics and seedling growth of sophora (sophora pachycarpa schrenk ex c. a. mey)

introductionsophora (sophora pachycarpa schrenk ex c. a. mey) is a perennial weed of fabaceae family which can propagated by seeds and through perennial roots. it is one of the invasive plants that can be seen in the most regions of iran, especially in the wheat fields, pastures and drylands, of khorasan. the biology of weeds and its importance in management has received a lot of attention in recent years. in fact, it is necessary to know the biological characteristics and key relationships between weeds and crops to control weeds in an agricultural ecosystem. also, the role of environmental conditions on weed management is very important. given this, the present study seeks to investigate the effects of environmental conditions (salinity and drought stress) on germination characteristics of sophora. materials and methodsin order to investigate the effect of salinity and drought stress on germination characteristics and seedling growth of sophora, two separate experiments were conducted in germination stage as a completely randomized design with four replications in the year 2017-2018 in research laboratories at agricultural college of ferdowsi university of mashhad. peg 6000 was used for drought stress and nacl, for salinity stress. the treatments included drought and salinity stress levels (0, -0.1, -0.2, -0.4, -0.8, -1, -1.2, -1.4 and -1.5 mpa). seeds were disinfected with sodium hypochlorite (1%) solution for 2 minutes, and were then washed with distilled water. the measured traits were germination percentage, germination rate, average germination time, radicle length, plumule length and fresh weight of radicle, plumule and seedling. the statistical analysis of the data was done by sas 9.1 and sigma plot 12.3 software. results and discussionanalysis of variance results showed that the effect of salinity levels on all traits was very significant (p≤ 0.01). maximum germination was observed in control treatment and at the level of -1.5 mpa salinity, the germination stopped. also, the effect of drought levels on all traits was very significant (p≤ 0.01) and at the level of -1 mpa drought, the germination stopped. fitting of the three-parameter sigmoid model provided a successful estimation of the relationship between salt and drought stress levels and germination percentage of sophora.this model showed that salinity and drought stress at -1.08 and -0.43 mpa, respectively, caused a 50% reduction in maximum germination percentage of sophora, and it can be concluded that the sensitivity of this weed to drought is more than to salinity, and the existence of salinity and drought stress can decrease growth indices of this weed at germination and seedling stages.conclusionsit was concluded that with the increase in both the drought and salinity stress, all the growth characteristics of sophora significantly decreased and the effect of salinity stress on percentage of germination and germination rate resulted from the toxic effect of ion salts. whereas, the reduction of seedling growth traits was both the toxic effect of ion salts and osmotic potential. it seems that sufficient information about this weed is vital for the selection of the best control method, could help us to come up with new control approaches for this invasive weed. considering the increase of salinity and drought in the country’s soils due to the decrease of rainfall and climate change, and with the according to sophora tolerance to salinity and its relative tolerance to drought, there is a possibility of expanding the range of presence of this weed in the conditions of salinity and drought of the soil, but for more accurate evaluation, it is necessary to conduct complementary experiments in the field and in the greenhouse conditions.