مدلسازي جوانه زني بذر كاملينا (Camelina sativa L.) با استفاده از مدل هالوتايم

Modeling seed germination of Camelina sativa L. using halotime model

ﭼﮑﯿﺪه در ﻣﻄﺎﻟﻌﻪ ﺣﺎﺿﺮ از ﻣﺪل ﻫﺎﻟﻮﺗﺎﯾﻢ ﺟﻬﺖ ﺗﻮﺻﯿﻒ ﺟﻮاﻧﻪزﻧﯽ ﺑﺬر ﮐﺎﻣﻠﯿﻨﺎ ).Camelina sativa L ﺑﻪ ﺗﻨﺶ ﺷﻮري اﺳﺘﻔﺎده ﮔﺮدﯾﺪ. آزﻣﺎﯾﺶ ﺑﻪ ﺻﻮرت ﻃﺮح ﭘﺎﯾﻪ ﮐﺎﻣﻼ ﺗﺼﺎدﻓﯽ ﺑﺎ ﭼﻬﺎر ﺗﮑﺮار در دﻣﺎي 20 درﺟﻪ ﺳﺎﻧﺘﯽﮔﺮاد و در ﭘﻨﺞ ﺳﻄﺢ ﺗﻨﺶ ﺷﻮري )ﺻﻔﺮ، 50، 100، 150 و 200 ﻣﯿﻠﯽ ﻣﻮﻻر( اﻧﺠﺎم ﺷﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﺑﺎ اﻓﺰاﯾﺶ ﺳﻄﻮح ﺗﻨﺶ ﺷﻮري، درﺻﺪ و ﺳﺮﻋﺖ ﺟﻮاﻧﻪزﻧﯽ ﺑﻪ ﻃﻮر ﻣﻌﻨﯽ داري ﮐﺎﻫﺶ ﯾﺎﻓﺖ. اﻓﺰاﯾﺶ ﺗﻨﺶ ﺷﻮري از ﺻﻔﺮ ﺗﺎ 200 ﻣﯿﻠﯽ ﻣﻮﻻر ﻣﻨﺠﺮ ﺑﻪ ﮐﺎﻫﺶ 18/5 و 80/1 درﺻﺪي ﺑﻪ ﺗﺮﺗﯿﺐ ﺻﻔﺎت درﺻﺪ و ﺳﺮﻋﺖ ﺟﻮاﻧﻪ زﻧﯽ ﮔﺮدﯾﺪ، در ﺣﺎﻟﯽ ﮐﻪ ﻣﯿﺎﻧﮕﯿﻦ زﻣﺎن ﺗﺎ رﺳﯿﺪن ﺑﻪ 50 درﺻﺪ ﺟﻮاﻧﻪ زﻧﯽ 5/1 ﺑﺮاﺑﺮ ﻧﺴﺒﺖ ﺑﻪ ﺗﯿﻤﺎر ﺷﺎﻫﺪ اﻓﺰاﯾﺶ ﯾﺎﻓﺖ. ﺛﺎﺑﺖ ﻫﺎﻟﻮﺗﺎﯾﻢ ﺑﺮاﺑﺮ 19460 ﻣﯿﻠﯽ ﻣﻮﻻر ﺳﺎﻋﺖ و آﺳﺘﺎﻧﻪ ﺗﺤﻤﻞ )ﺷﺪت ﺗﻨﺶ ﺷﻮري ﮐﻪ ﻣﺎﻧﻊ 50 درﺻﺪ ﺟﻮاﻧﻪزﻧﯽ ﺧﻮاﻫﺪ ﺷ(ﺪ ﺑﻪ ﺷﻮري ﺑﺮاﺑﺮ 271/8 ﻣﯿﻠﯽ ﻣﻮﻻر )ﻣﻌﺎدل 1/19- ﻣﮕﺎﭘﺎﺳﮑﺎ(ل ﺑﺮآورد ﮔﺮدﯾ.ﺪ ﮐﺎﻫﺶ درﺻﺪ و ﺳﺮﻋﺖ ﺟﻮاﻧﻪ زﻧﯽ در ﺳﻄﻮح ﺑﺎﻻ ﺗﻨﺶ ﺷﻮري را ﻣﯽ ﺗﻮان ﺑﻪ ﮐﺎﻫﺶ ﺷﺪﯾﺪ ﭘﺘﺎﻧﺴﯿﻞ اﺳﻤﺰي و ﻋﺪم ﺗﻮاﻧﺎﯾﯽ ﺑﺬر در ﺟﺬب آب و ﯾﺎ اﻓﺰاﯾﺶ اﺛﺮ ﺳﻤﯿﺖ ﯾﻮن ﻫﺎي ﺷﻮري )ﺳﺪﯾﻢ و ﮐﻠﺮ( ﻧﺴﺒﺖ داد. در ﻣﺠﻤﻮع، ﻣﺪل ﻫﺎﻟﻮﺗﺎﯾﻢ ﺑﻪ ﺧﻮﺑﯽ ﻗﺎدر ﺑﻪ ﮐﻤﯽ ﺳﺎزي ﭘﺎﺳﺦ ﺟﻮاﻧﻪزﻧﯽ ﺑﺬر ﮐﺎﻣﻠﯿﻨﺎ در ﺷﺮاﯾﻂ ﺗﻨﺶ ﺷﻮري ﻣﯽﺑﺎﺷﺪ.

In this study, a halotime model was used to describe seed germination of camelina (Camelina sativa L.) under salinity stress. The experiment was conducted in a completely randomized design with four replications at 20 °C and five salinity levels (NaCl: 0, 50, 100, 150, 200 mM) was used. The results showed that the germination percentage (GP) and germination rate (GR) were significantly decreased by increasing salinity levels. GP and GR decreased by 18.5 and 80.1%, respectively, with the increasing salinity from 0 to 200 mM, while the mean germination time to reach 50th percentile increased by 5.1-folds as compared to the control condition. The halotime constant and salinity tolerance threshold value (salinity level for preventing 50% of germination) were estimated 19460 mM h and 271.8 mM (equal to -1.19 MPa), respectively. Decreasing GP and GR in high levels of salinity can be related to severe reduction of osmotic potential and the inability of seeds to absorb water and/or increasing toxicity effect of saline ions (Na and Cl). Overall, the halotime model could quantify well the germination response of camelina seed under saline conditions.