مدل سازي جوانه زني بذر سياه دانه (Nigella sativa L.) تحت تأثير تنش شوري و خشكي

Modelling seed germination of Nigella sativa L. under salt and drought stress

ﺗﻨﺶ ﻫﺎي ﻣﺤﯿﻄﯽ ﻣﺎﻧﻨﺪ ﺗﻨﺶ ﺷﻮري و ﺧﺸﮑﯽ از ﺟﻤﻠﻪ ﻋﻮاﻣﻞ ﻣﺤﯿﻄﯽ ﻣﻬﻢ ﻫﺴﺘﻨﺪ ﮐﻪ ﻣﺮاﺣﻞ ﻣﺨﺘﻠﻒ ﺗﻮﺳﻌﻪ ﻣﺤﺼﻮﻻت زراﻋﯽ، ﺑﻪ ﺧﺼﻮص ﻣﺮﺣﻠﻪ ي ﺟﻮاﻧﻪ زﻧﯽ را ﺗﺤﺖ ﺗﺄﺛﯿﺮ ﻗﺮار ﻣﯽ دﻫﻨﺪ. ﺑﻪ ﻣﻨﻈﻮر ﻣﺪل ﺳﺎزي ﺟﻮاﻧﻪ زﻧﯽ ﺑﺬر ﺳﯿﺎه داﻧﻪ در ﺷﺮاﯾﻂ ﺗﻨﺶ ﺷﻮري و ﺧﺸﮑﯽ آزﻣﺎﯾﺸﯽ در ﻗﺎﻟﺐ ﻃﺮح ﮐﺎﻣﻼ ﺗﺼﺎدﻓﯽ ﺑﺎ 4 ﺗﮑﺮار اﻧﺠﺎم ﺷﺪ. ﺗﯿﻤﺎرﻫﺎ ﺷﺎﻣﻞ ﭘﻨﺞ ﺳﻄﺢ ﺷﻮري )0، 50، 100، 150، 200 ﻣﯿﻠﯽ ﻣﻮﻻر ( و ﭼﻬﺎر ﺳﻄﺢ ﺧﺸﮑﯽ )0، 0/25-، 0/50-، 0/75- ﻣﮕﺎﭘﺎﺳﮑﺎل ( ﺑﻮدﻧﺪ. ﻃﺒﻖ ﻧﺘﺎﯾﺞ ﻫﺮ دو ﺗﻨﺶ ﺧﺸﮑﯽ و ﺷﻮري ﺑﻪ ﻃﻮر ﻣﻌﻨﯽ داري ﺑﺮ ﺻﻔﺎت درﺻﺪ و ﺳﺮﻋﺖ ﺟﻮاﻧﻪ زﻧﯽ ﺗﺄﺛﯿﺮﮔﺬار ﺑﻮدﻧﺪ. اﻓﺰاﯾﺶ ﺗﻨﺶ ﺧﺸﮑﯽ از ﺻﻔﺮ ﺗﺎ 0/75- ﻣﮕﺎﭘﺎﺳﮑﺎل ﻣﻘﺪار درﺻﺪ و ﺳﺮﻋﺖ ﺟﻮاﻧﻪ زﻧﯽ ﺑﻪ ﺗﺮﺗﯿﺐ 57/3 و 86/0 درﺻﺪ و اﻓﺰاﯾﺶ ﺗﻨﺶ ﺷﻮري از ﺻﻔﺮ ﺗﺎ 200 ﻣﯿﻠﯽ ﻣﻮﻻر ﻣﻘﺪار ﻫﺮ دو ﺻﻔﺎت ﺑﻪ ﺗﺮﺗﯿﺐ 24/5 و 67/4 درﺻﺪ ﮐﺎﻫﺶ داد. آﺳﺘﺎﻧﻪ ﺗﺤﻤﻞ ﺑﻪ ﺧﺸﮑﯽ و ﺷﻮري ﺑﺮاي رﺳﯿﺪن ﺑﻪ 50 درﺻﺪ ﺟﻮاﻧﻪ زﻧﯽ ﺑﻪ ﺗﺮﺗﯿﺐ 0/87 - ﻣﮕﺎﭘﺎﺳﮕﺎل ﺗﻮﺳﻂ ﻣﺪل ﻫﯿﺪروﺗﺎﯾﻢو 309/1 ﻣﯿﻠﯽ ﻣﻮﻻر )ﻣﻌﺎدل 1/35- ﻣﮕﺎﭘﺎﺳﮕﺎ(ل ﺗﻮﺳﻂ ﻣﺪل ﻫﺎﻟﻮﺗﺎﯾﻢ ﺗﺨﻤﯿﻦ زده ﺷﺪ ﮐﻪ ﻧﺸﺎن دﻫﻨﺪه 35/6 درﺻﺪ ﺗﻨﻈﯿﻢ اﺳﻤﺰي در ﺷﺮاﯾﻂ ﺗﻨﺶ ﺷﻮري ﻣﯽ ﺑﺎﺷ.ﺪ درﻣﺠﻤﻮع، از ﭘﺎراﻣﺘﺮﻫﺎي ﺑﻪ دﺳﺖ آﻣﺪه در اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﻣﯽ ﺗﻮان در ﻣﺪل ﻫﺎي ﭘﯿﺶ ﺑﯿﻨﯽ ﺟﻮاﻧﻪ زﻧﯽ ﺑﺬر ﺳﯿﺎه داﻧﻪ اﺳﺘﻔﺎده ﻧﻤﻮد.

Environmental stresses including salinity and drought stress are important environmental factors that affect different stages of crop development, especially the germination stage. Therefore, in order to seed germination modeling of Nigella sativa L. under salinity and drought stresses, an experiment was conducted in a completely randomized design with four replications. Treatments were included five levels of salinity (0, 50, 100, 150, 200 mM, provided using NaCl) and four levels of water potential (ψ, 0, –0.25, –0.50, –0.75 MPa, provided using PEG8000). According to the results, the germination percentage (GP) and germination rate (GR) were significantly influenced by both drought and salinity stresses. Increasing drought stress from 0 to –0.75 MPa decreased GP and GR by 57.3 and 86.0% and also increasing salinity stress from 0 to 200 mM decreased both traits by 24.5 and 67.4%, respectively. Drought and salinity tolerance threshold value to reach 50% germination was estimated to be –0.87 MPa by hydrotime model and 309.1 mM (equal to –1.35 MPa) by halotime model, indicating 35.6% of osmotic adjustment under saline conditions. Generally, the parameters obtained in this study can be used in simulation models of Nigella sativa L. germination