| Abstract | 第1-14页 |
| 摘要 | 第14-16页 |
| Chapter One:Introduction | 第16-37页 |
| Background | 第16页 |
| ·Research progress at home and abroad | 第16-33页 |
| ·Soil microbial diversity and limiting factors | 第16-19页 |
| ·Advances in research methods of soil microorganisms | 第19-25页 |
| ·Factors influencing soil microbial diversity | 第25-30页 |
| ·The nature and function of ammonium oxidizers | 第30-31页 |
| ·Research Foundation and development | 第31-33页 |
| ·The purpose and significance of the study | 第33-37页 |
| ·The purpose of the study | 第33-34页 |
| ·The main objectives of the study | 第34-35页 |
| ·Hypothesis | 第35页 |
| ·Research contents | 第35-37页 |
| Chapter Two:The introduction of the test base and the main measurement methods | 第37-40页 |
| ·Description of the study site | 第37-38页 |
| ·Analytical items and methods of measurement | 第38-39页 |
| ·Determination of basic physical and chemical properties of soil | 第38-39页 |
| ·Determination of ammonium nitrogen and nitrate nitrogen | 第39页 |
| ·Data analysis | 第39-40页 |
| Chapter Three:Long-term effect of plastic film mulching and fertilization on bacterialcommunities revealed by high through-put sequencing | 第40-68页 |
| ·Introduction | 第40-42页 |
| ·Materials and methods | 第42-45页 |
| ·Study site and experimental design | 第42-43页 |
| ·Soil sampling | 第43页 |
| ·Soil DNA extraction and PCR amplification | 第43-44页 |
| ·Illumina Miseq sequencing | 第44页 |
| ·Processing the metagenomic data | 第44页 |
| ·Statistical analysis | 第44-45页 |
| ·Results | 第45-63页 |
| ·Soil properties and microbial biomass C | 第45-47页 |
| ·Microbial community diversity | 第47-51页 |
| ·Core bacterial community shared by samples with and without plastic film mulching | 第51-55页 |
| ·Relative abundance of specific bacterial taxa | 第55-60页 |
| ·Relationship between bacterial communities and soil properties | 第60-63页 |
| ·Discussion | 第63-66页 |
| ·Soil properties and microbial biomass C | 第63页 |
| ·Soil microbial diversity | 第63-64页 |
| ·Soil bacterial abundance | 第64-66页 |
| ·Relationship between bacterial communities and soil properties | 第66页 |
| ·Conclusions | 第66-68页 |
| Chapter Four:Abundance and community structure of Ammonium oxidizing bacteria andarchaea under plastic film mulching and long-term fertilization | 第68-98页 |
| ·Introduction | 第68-70页 |
| ·Materials and Methods | 第70-81页 |
| ·Study site and experimental design | 第70页 |
| ·Soil sampling | 第70页 |
| ·Soil DNA extraction | 第70-71页 |
| ·Fluorescence quantitative polymerase chain reaction (QPCR) | 第71-77页 |
| ·Denaturing Gradient Gel Electrophoresis | 第77-79页 |
| ·Polymerase chain reaction of AOB 16S rRNA gene amplification | 第79-80页 |
| ·PCR-DGGE analysis of AOB using 16S rRNA gene | 第80-81页 |
| ·Statistical Analysis | 第81页 |
| ·Results and discussion | 第81-97页 |
| ·Soil physicochemical properties | 第81-84页 |
| ·AOB and AOA amoA gene abundance of June, July, and October with and without mulching | 第84-86页 |
| ·Effect of long-term fertilization on community diversity of AOB with or without film for July and October | 第86-89页 |
| ·Effect of long-term fertilization on soil AOB community structure | 第89-95页 |
| ·Relationship between AOB diversity and soil physicochemical properties84 | 第95-97页 |
| ·Conclusions | 第97-98页 |
| Chapter Five:Seasonal variations of bacterial communities influenced by plastic filmmulching and fertilization by high through-put sequencing technology | 第98-127页 |
| ·Introduction | 第98-100页 |
| ·Materials and methods | 第100-103页 |
| ·Study site and experimental design | 第100页 |
| ·Soil sampling | 第100页 |
| ·Soil DNA extraction | 第100页 |
| ·PCR amplification | 第100-101页 |
| ·Illumina HiSeq platform | 第101页 |
| ·Processing of sequencing data analysis | 第101-103页 |
| ·Statistical analysis | 第103页 |
| ·Results and discussion | 第103-126页 |
| ·Summary of High-throughput sequencing data | 第103页 |
| ·Maize grain yield as a measure of soil quality | 第103-106页 |
| ·Bacterial community diversity under long-term fertilization | 第106-116页 |
| ·Long-term effect of fertilization on the relative abundance of specific bacterial taxa | 第116-119页 |
| ·Long-term fertilization of bacterial Orders with or without mulching for July and October | 第119-122页 |
| ·Relationship between soil bacterial communities and soil physicochemical properties | 第122-126页 |
| ·Conclusions | 第126-127页 |
| Chapter six:Conclusions and novelty of research | 第127-130页 |
| ·Conclusions | 第127-129页 |
| ·Novelty of research | 第129-130页 |
| References | 第130-153页 |
| Acknowledgements | 第153-155页 |
| Publications | 第155-156页 |
| Statistics of tables and figures in the thesis | 第156页 |
