| 摘要 | 第1-9页 |
| Abstract | 第9-11页 |
| 1 Introduction | 第11-23页 |
| ·Background study | 第11-12页 |
| ·Impact of Pesticide usage on Soil Microorganism | 第12页 |
| ·Atrazine Application History | 第12-14页 |
| ·Gains of Nutrients to Soil | 第14-16页 |
| ·Role of soil Microorganisms in Soil | 第16-17页 |
| ·Internal Transformations of Nutrients in Soil | 第17-19页 |
| ·Sulfur (S) | 第19页 |
| ·Gains of Sulfur to Soil | 第19-20页 |
| ·Microorganisms involved in soil sulfur cycle | 第20-22页 |
| ·Aims and Objectives of the Study | 第22-23页 |
| 2 Materials and methods | 第23-29页 |
| ·Materials and Methods in Experiment 1 | 第23-24页 |
| ·Plant materials and atrazine stress treatment | 第23页 |
| ·Measurement of the Ascorbate and Glutathione contents | 第23页 |
| ·Determination of Glutathione S-transferase and Glutathione Reductase | 第23-24页 |
| ·Determination of Hydrogen peroxide and superoxide radicals | 第24页 |
| ·Statistical analysis | 第24页 |
| ·Materials and Methods in Experiment 2 | 第24-29页 |
| ·Plant materials and growth conditions | 第24-25页 |
| ·ROS detection by confocal laser scanning fluorescence microscopy (CLSM) | 第25页 |
| ·Enzyme extraction and antioxidant enzymes assays (APX, CAT and POD) | 第25-26页 |
| ·Reactive oxygen species quantification and Chlorophyll contents analysis | 第26-27页 |
| ·Gene Expression Analysis (c APX, Cc POD, chl Cu/Zn SOD and psb A) | 第27页 |
| ·Atrazine content determination by Gas Chromatography | 第27-28页 |
| ·Statistical analysis | 第28-29页 |
| 3 Result analysis | 第29-43页 |
| ·Soil total DNA extraction: | 第29页 |
| ·PCR products of apr A gene with soil total DNA as template | 第29-30页 |
| ·PCR product purification | 第30-31页 |
| ·Cloning and sequencing | 第31-32页 |
| ·Gene Bank Accession number and Ide ntification of Closet Sequence | 第32-33页 |
| ·Similarity Analysis | 第33-35页 |
| ·Phylogenetic Analysis Based on apr A gene Sequence | 第35-36页 |
| ·Variability of Soil Microbial Biomass and DNA in Summer Season | 第36-38页 |
| ·Variability of Soil Microbial Biomass and DNA in Spring Season | 第38-39页 |
| ·Impact of Seasonal Variations and Fertilizers on Soil MB, DNA and ODR | 第39-41页 |
| ·Correlation between Spring and Summer Variations on Selected Parameters | 第41-43页 |
| 4 Discussion | 第43-49页 |
| ·influence of atrazine on soil microbial comm unities | 第43页 |
| ·Selection of Soil sulfur 16S r RNA genes | 第43-45页 |
| ·Evaluation of microbial diversity by using apr A gene | 第45-46页 |
| ·Sulfate Reducing and oxidizing prokaryotic diversity by clo ning of apr A gene | 第46-47页 |
| ·Soil biological Indicators | 第47页 |
| ·Soil Microbial Biomass | 第47-48页 |
| ·Impact of organic fertilizers on soil microbial b iomass | 第48页 |
| ·Impact of inorganic fertilizers on soil microbial biomass | 第48页 |
| ·Impact of seasonal variations on soil microbial b iomass | 第48页 |
| ·Relationship between soil microbial biomass and soil DNA | 第48-49页 |
| 5 Conclusion | 第49-51页 |
| Acknowledgement | 第51-52页 |
| References | 第52-61页 |
| Research Publication in Period of Ph.D Education | 第61页 |
