Study On Exogenous Calcium On Modulationg Effects Of Physiological And Biochemical Of Jatropha Curcas L Under Low-temperature Stress

Jatropha curcas L.is emerging energy source plant which have a high economic value,but the geographical distribution has regional,because the temperature,it seriously effects exploitation and utilization of Jatropha .Presently,the articles have focused on studying Biodiesel extraction and Biological pesticide research.however,it is sparse for the physiological and chemic characteristic ,so this texts study the cold-resistant and discuss the theory and technology of increasing the coldness,and apply a basic theory and technology for Jatropha introduction and Cold breeding.Calcium is a second message of tanslating signals of environment stess in plant cell.It participates in transmission adversity, active participation in Physiology and biochemistry reaction ,and plays imprortant role in message transduction of the environment stress involving low temperature .The research uses Jatropha seedling as sample to study the regulation mechanism of Ca²⁺ on cold-resistant the result were as follows:1.characteristics of Jatropha seed.With the extend of cold stress ,Jatropha seed germination rate, germination index, and the seed vigor present rapid rising and then gradually declined after different Ca²⁺treatment and better than Contrast experiments.The concentration at 20mmol/LCa²⁺ treatment showed the best its corresponding index are 37.33%,34.00%,27.51%,7.19%.2.For the relative penetrability of cell membrane and MDA content ,they all have increase on different degree.Treated by Ca²⁺solution,the relative penetrability of seedling cell membrane and MDA content vary gently.besides 80mmol/LCa²⁺for MDA content more than Contrast experiments, other treatments are all lower in relative penetrability of cell membrane and MDA content.3.Under low temperature stress, The root activity of Jatropha was taken changing trend of gradually rising and declined with the extend of cold stress.Under the same condition,calcium-treated Jatropha seedlings are better in root activity than Contrast experiments, different calcium-treated shows extremely significant difference. The results indicates that spraying calcium can improve the root activity of Jatropha, alleviated injury by low temperature to the root activity of Jatropha.4.Under low temperature , adding certain concentration Ca²⁺can obviously improve content of soluble protein,soluble sugar and proline, enhance the cold resistance capacity,but high concentration hasthe opposite effect. The results indicates that 20mmol/LCa²⁺ treatment play a positive role in increasing soluble sugar,soluble sugar and proline content for Jatropha,and showed best effects.5.After different calcium-treated, the antioxidant enzyme activity of Jatropha showd different variation trend with the extend of cold stress, SOD was taken gradually rising on the whole,however , POD,CAT showed rises in advance then falls on the whole. activities of POD and CAT increased at first and then decreased. By the fourth day, which were up to a maximum value. Different Ca²⁺ consistency had different effects in different stress times, in the late chilling stress, activities of SOD POD and CAT rangeability were largely, spraying calcium 20mmol/LCa²⁺increased SODactivity of Jatropha,and alleviated decline of POD and CAT activity6.The experiment investigated,under low temperature, the effects of different calcium-treated on Pn of Jatropha seedling were significant, Pn of Jatropha leaves trended to decrease gradually,but SPAD content changed slowly.During chilling stress, Pn of Jatropha declined slowly and SPAD content is in highest-level after calcium-treated. The results indicated that spraying Ca²⁺can effectively alleviate injury by low temperature to photosynthesis and played positive protection for Jatropha effectively7.A certain concentrations of calcium can reduces destructiveness to photosynthetic apparatus under low-temperature.but it effects little on Fv/Fm.Results indicated that ,with the extend of cold stress,different consistency treatments showed gradually declined trend to Fm,Fv/Fm,(Fv/Fo),ΦPSâ…¡,qP and NPQ.under low temperature, 20mmol/LCa²⁺treatment can slow down rising of Fo, restrained qP and NPQ to decrease,increase photochemical activity of PSâ…¡, limit the damage to PSâ…¡potential active center,Slow PSâ…¡electron-transport quantum decreased,improve the efficiency ofΦPSâ…¡8.The experiment studied the effects of different concentrations of calcium treatment on seedling characteristics of Jatropha,physiological and chemic index,photosynthetical system and chlorophyll fluorescence.According to subordinate function,analyzed anti-cold ability of Jatropha.unde low temperature stress. anti-cold ability of Jatropha(from strong to weak): 20mmol/L 40mmol/L,60mmol/L,80mmol/L,blank test sample.The concentration at 20mmol/L Ca²⁺treatment showed best.