| Abstract | 第8-10页 |
| 摘要 | 第11-13页 |
| 1 Introduction | 第13-25页 |
| 1.1 Background Study | 第13-14页 |
| 1.2 Applications of Agricultural Chemicals Including Fertilizers and Herbicides | 第14-16页 |
| 1.3 Impact of Agricultural Chemicals on Soil Microbial Communities | 第16-17页 |
| 1.4 Relationship between Soil Structure and Fertilizer Application | 第17-21页 |
| 1.4.1 Role of Soil Microorganisms | 第18-19页 |
| 1.4.2 Internal Transformations of Nutrient in Soil | 第19-21页 |
| 1.5 Soil Elemental Sulfur(S) | 第21-24页 |
| 1.5.1 Sulfur Recycling in soil | 第21-22页 |
| 1.5.2 Microorganisms involved in soil sulfur cycle | 第22-24页 |
| 1.6 Aims and Objectives of the Study | 第24-25页 |
| 2 Materials and Methods | 第25-32页 |
| 2.1 Influence of Fertilizers Application on Soil Microbial Biomass and DNA Concentration | 第25-26页 |
| 2.1.1 Sampling Site and Experiment Description | 第25页 |
| 2.1.2 Soil Sampling | 第25页 |
| 2.1.3 Detection of Microbial Biomass Carbon and Oxygen availability | 第25-26页 |
| 2.1.4 Detection and Bacterial Cell Counting in Soil | 第26页 |
| 2.1.5 Analysis of Sulfate Reducing Bacterial Quantity by Fluorescence in situ Hybridization(FISH) | 第26页 |
| 2.2 Affect of Atrazine on Soil Microbial Communities Involved in Soil Sulfur Cycle | 第26-27页 |
| 2.2.1 Soil Sampling and Characteristics | 第26-27页 |
| 2.2.2 Experimental Design | 第27页 |
| 2.3 Detection of soil Microbial Communities Involved in Soil Sulfur Cycle | 第27-31页 |
| 2.3.1 DNA Extraction from soil | 第27-28页 |
| 2.3.2 PCR amplification | 第28-29页 |
| 2.3.3 The Clone of the Amplified Gene Fragments | 第29-30页 |
| 2.3.4 Diversity Analysis | 第30-31页 |
| 2.4 Statistical Analysis | 第31-32页 |
| 3 Results | 第32-48页 |
| 3.1 Soil Microbial Response Against Agricultural Fertilizers(Organic and Inorganic) | 第32-38页 |
| 3.1.1 Impact of Fertilizers on Soil MB,DNA and ODR Enrichment During Spring and Summer Season | 第32-34页 |
| 3.1.2 Correlation of Soil MB and DNA Concentrations in Summer Season | 第34-36页 |
| 3.1.3 Correlation of Soil Microbial Biomass and DNA Concentration in Spring Season | 第36-38页 |
| 3.2 Microbial Response under Atrazine Stress | 第38-48页 |
| 3.2.1 Affect of atrazine on Concentration of soil MB and DNA | 第38-40页 |
| 3.2.2 Total Microbial Count and SRB Count under Atrazine Stress | 第40-41页 |
| 3.2.3 Impact on Enrichment of Soil Sulfur Genes aprA and dsrA | 第41-44页 |
| 3.2.4 Identification of Closest Sequence | 第44-46页 |
| 3.2.5 Similarity Analysis | 第46页 |
| 3.2.6 Detection of aPrA and dsrA gene under atrazine stress | 第46-48页 |
| 4 Discussion | 第48-54页 |
| 4.1 Impact of Agricultural Chemicals on Concentration of Soil Microbial Biomass and DNA | 第48-49页 |
| 4.2 Relationship Between Soil Microbial biomass and soil DNA | 第49页 |
| 4.3 Impact of Fertilizers Type on soil Microbial Biomass | 第49-50页 |
| 4.4 Influence of Atrazine on Soil Microbial Communities | 第50页 |
| 4.5 Impact of Atrazine Stress on Enrichment of Genes Involved in Soil Sulfur Cycle | 第50-53页 |
| 4.6 Sulfate Reducing and Oxidizing MicrobiaGroup Enrichment | 第53-54页 |
| 5 Conclusion | 第54-56页 |
| 结论 | 第56-57页 |
| Acknowledgement | 第57-58页 |
| References | 第58-68页 |
| Research Publication in Period of Ph.D Education | 第68-69页 |
| Annexures | 第69-77页 |
