Study On Adversity Stress Of Photosynthesis And Physiological Characteristics On Aegiceras Corniculatum Seedlings

In this study,use the Aegiceras corniculatum seedlings as test material by measuring different NaCl concentrations,waterlogging time,different nitrogen application rate and a high concentration of CO2 stress,of photosynthetic characteristics change(Pn,Tr,Cond,Ci,etal.)and use the formula to calculate the WUE?CUE under different treatments.Use the Farquhar model while using light fitting PAR response curves at different gradients and extract the main characteristic parameters.The test material take back to the lab measured physiological and biochemical(total Chi content,SS content,SP content,POD activity,SOD activity,MDA content,free proline content,conductivity).The purpose of this study is to better understand the physiological and biochemical of Aegiceras corniculatum(photosynthesis and transpiration,content of nutrients and resistance related enzymes)parameters in different variation under stress,adversity threshold Aegiceras explore for reforestation of mangroves provide scientific basis.The study of results are as follows:1.In different concentrations of NaCl stress,Aegiceras corniculatum seedlings use solar energy utilization become weakened,the photosynthetic parameters are reducing,treatment group 500 mmol·L-1 is reduced to a lesser extent.High concentrations of NaCl seriously affect net photosynthetic rate in leaves;WUE and CUE handle at a higher level in 500 mmol·L-1 that protect the normal metabolism of leaf cells.2.Nitrogen application rate on photosynthetic parameters Aegiceras corniculatum seedlings showed some inhibition,net photosynthetic rate decreased,reducing the accumulation of organic matter;16 mg·L-1 treated transpiration rate and stomatal conductance becomes large,possibly by increasing metabolism to water maintain the photosynthetic metabolism of cells;WUE and CUE decreased,indicating that the metabolic activity after stress Aegiceras seedlings weakened.3.In different times of waterlogging,12h waterlogging improve light utilization seedlings,but the overall level of net photosynthetic rate of decline compared to the control.Transpiration rate and stomatal conductance prolonged waterlogging leaves increased,while WUE and CUE is not high.4.Under different concentrations of NaCl stress significantly decreased chlorophyll content,soluble protein content,POD activity,SOD,MDA increased the first and drop after,free proline and leaf conductance are increasing.Showed that increasing the degree of leaf injury.5.In different nitrogen treatment,the chlorophyll content decreased,soluble protein,soluble sugar,MDA first and then decreased,SOD significantly lower at 16 mg·L-1 processing,POD,free proline and leaf conductance increasingly the higher,indicating Aegiceras corniculatum seedlings severely nitrogen stress injuries.6.Waterlogging stress reduces leaf chlorophyll content,soluble protein,soluble sugar,SOD,MDA increased after the first drop,POD,free proline,leaf conductance increasing,indicating Aegiceras seedlings to withstand adversity in the environment also severely damaged.7.The high concentrations of CO2 has a serious impediment to the growth of Aegiceras corniculatum seedlings,such as energy efficiency and a significant reduction in net photosynthetic rate,so that weakened synthetic organics,and change the light response curve trend transpiration rate and stomatal conductance,CUE and WUE decreased,it is difficult to maintain basic metabolic activity of cells.Various physiological characteristics of seedlings exhibited serious injury.