| ABSTRACT | 第7-8页 |
| 摘要 | 第9-15页 |
| CHAPTER 1.Literature review | 第15-36页 |
| 1.1 Research background | 第15-19页 |
| 1.2 Literature review | 第19-33页 |
| 1.2.1 Fractionation of selenium in soil | 第19-21页 |
| 1.2.2 Fractionation of mercury in soil | 第21-23页 |
| 1.2.3 The bioavailability,uptake ability of selenium and mercury in soil | 第23-25页 |
| 1.2.4 Changes in mercury speciation and bioavailability in soil after exogenous selenium application | 第25-28页 |
| 1.2.5 Uptake and translocation of mercury in soil–plant systems after exogenous selenium application | 第28-31页 |
| 1.2.6 The physiological and biochemical mechanisms of plants detoxification mercury | 第31-33页 |
| 1.3 Objectives of the study | 第33-34页 |
| 1.4 Main research content | 第34-35页 |
| 1.4.1 The role of selenite and selenate application on the bioavailability of mercury in soil | 第34页 |
| 1.4.2 Detoxicity mechanisms of mercury in plants by amendment selenite and selenate | 第34页 |
| 1.4.3 The effects of mercury phytotoxicity on speciation and bioavailability of selenium in selenite-and selenite-treated soil | 第34页 |
| 1.4.4 The effects of mercury phytotoxicity on physiological and biochemical mechanism of pak choi under selenite-and selenate-treated soil | 第34-35页 |
| 1.5 The main schematic for the study | 第35-36页 |
| CHAPTER 2.Effects of selenium application on speciation and bioavailability of mercury in soil-plant system when selenite and selenate application | 第36-52页 |
| 2.1 Introduction | 第36-37页 |
| 2.2 Materials and methods | 第37-41页 |
| 2.2.1 Experimental materials | 第37-38页 |
| 2.2.2 Pot experiments | 第38-39页 |
| 2.2.3 Sample preparation | 第39页 |
| 2.2.4 Chemical analysis | 第39-40页 |
| 2.2.5 Quality control | 第40-41页 |
| 2.2.6 Statistical data analysis | 第41页 |
| 2.3 Results | 第41-47页 |
| 2.3.1 Effects of exogenous selenite and selenate on mercury bioavailability | 第41-42页 |
| 2.3.2 Changes of mercury fractions in soil for different selenium applications | 第42-45页 |
| 2.3.3 IR value of mercury changes in soil before planting and after harvest | 第45-46页 |
| 2.3.4 Correlation between different mercury fractions in soil and uptake of mercury by pak choi | 第46-47页 |
| 2.4 Discussions | 第47-51页 |
| 2.4.1 The influence of Hg–Se co-exposure on the mercury bioavailability | 第47-48页 |
| 2.4.2 Comparing the influence of selenite and selenate on the inhibition of the mercury bioavailability in soil | 第48-51页 |
| 2.5 Summary | 第51-52页 |
| CHAPTER 3.The physiological and biochemical responses of plant under Hg stress with exogenous Se,and comparing the effectiveness of selenite and selenate application | 第52-67页 |
| 3.1 Introduction | 第52-53页 |
| 3.2 Materials and methods | 第53-56页 |
| 3.2.1 Experimental materials | 第53页 |
| 3.2.2 Pot experiments | 第53页 |
| 3.2.3 Sample preparation | 第53-54页 |
| 3.2.4 Determination methods | 第54-56页 |
| 3.2.5 Statistical data analysis | 第56页 |
| 3.3 Results | 第56-62页 |
| 3.3.1 Effect of applied selenite and selenate pak choi growth under mercury stress | 第56-58页 |
| 3.3.2 Effect of applied selenium on photosynthetic pigments of pak choi under mercury stress | 第58-59页 |
| 3.3.3 Effects of applied selenium on the antioxidant system of pak choi under mercury stress | 第59-61页 |
| 3.3.4 Effects of applied selenium on peroxidant of pak choi under mercury stress | 第61-62页 |
| 3.4.Discussion | 第62-66页 |
| 3.4.1 Effects of applied selenium on detoxification mechanism of mercury under mercury stress | 第62-64页 |
| 3.4.2 Comparing the effects of applied selenite and selenate on detoxification of mercury | 第64-66页 |
| 3.5 Summary | 第66-67页 |
| CHAPTER 4.Effects of mercury phytotoxicity on speciation and bioavailability of selenium in soil-plant system when selenite-and selenite-treated soil | 第67-82页 |
| 4.1 Introduction | 第67-69页 |
| 4.2 Materials and methods | 第69-71页 |
| 4.2.1 Experimental materials | 第69页 |
| 4.2.2 Pot experiments | 第69页 |
| 4.2.3 Sample preparation | 第69页 |
| 4.2.4 Chemical analysis | 第69-70页 |
| 4.2.5 Quality control | 第70-71页 |
| 4.2.6 Statistical data analysis | 第71页 |
| 4.3 Results | 第71-78页 |
| 4.3.1 Effects of mercury phytotoxicity on selenium bioavailability when selenite-and selenite-treated soil | 第71-73页 |
| 4.3.2 Effects of mercury phytotoxicity on selenium fractions in soil when selenite-and selenite-treated soil | 第73-76页 |
| 4.3.3 Effects of mercury phytotoxicity on MF value selenium changes in soil when selenite-and selenite-treated soil | 第76-77页 |
| 4.3.4 Correlation between different selenium fractions in soil and uptake of selenium by pak choi | 第77-78页 |
| 4.4 Discussions | 第78-81页 |
| 4.4.1 Effects of mercury phytotoxicity on speciation and bioavailability of selenium.. | 第78-79页 |
| 4.4.2 Comparing the effects of mercury phytotoxicity on speciation and bioavailability of selenium after treated selenite and selenate | 第79-81页 |
| 4.5 Summary | 第81-82页 |
| CHAPTER 5.Effects of mercury phytotoxicity on physiological and biochemical mechanism of pak choi under treated Se condition,with the exogenous selenite and selenite | 第82-95页 |
| 5.1 Introduction | 第82-84页 |
| 5.2 Materials and methods | 第84页 |
| 5.2.1 Experimental materials | 第84页 |
| 5.2.2 Pot experiments | 第84页 |
| 5.2.3 Sample preparation | 第84页 |
| 5.2.4 Determination methods | 第84页 |
| 5.2.5 Statistical data analysis | 第84页 |
| 5.3 Results | 第84-92页 |
| 5.3.1 The effects mercury phytotoxicity on pak choi growth in selenite-and selenite-treated soil | 第84-86页 |
| 5.3.2 The effects mercury phytotoxicity on photosynthetic pigments of pak choi in selenite-and selenite-treated soil | 第86-87页 |
| 5.3.3 The effects mercury phytotoxicity on the antioxidant system of pak choi in selenite-and selenite-treated soil | 第87-91页 |
| 5.3.4 The effects mercury phytotoxicity on peroxidant of pak choi in selenite-and selenite-treated soil | 第91-92页 |
| 5.4 Discussion | 第92-94页 |
| 5.4.1 Comparing the effects of exogenous selenite and selenate alone on the physiological and biochemical mechanism of pak choi | 第92-93页 |
| 5.4.2 Comparing the influence of mercury toxicity on the physiological and biochemical mechanism of pak choi in Se(Ⅳ)-or Se(Ⅵ)-treated soil | 第93-94页 |
| 5.5 Summary | 第94-95页 |
| CHAPTER 6.Main conclusion and future perspective | 第95-98页 |
| 6.1 Main conclusion | 第95-96页 |
| 6.2 Highlights | 第96页 |
| 6.3 New findings | 第96-97页 |
| 6.4 Future perspective | 第97-98页 |
| REFERENCES | 第98-114页 |
| ACKNOWLEDGEMENT | 第114-115页 |
| ABOUT THE AUTHOR | 第115-116页 |
