目录
摘要Ⅲ
关键词Ⅲ
AbstractⅣ
引言
引言1
1 材料与方法2
材料与技术路线 2
样品采集与预处理2
1.1.2 技术路线3
1.2 土壤氨氧化微生物群落结构分析3
1.2.1 土壤总DNA的提取和检测3
1.2.2 氨氧化微生物高通量测序3
1.2.3 统计分析3
1.3 土壤理化性质分析4
1.4 土壤N的矿化和硝化功能测定4
1.4.1 土壤N净矿化速率测定4
1.4.2 土壤硝化势的测定方法4
2 结果与分析5
2.1 土壤理化性质5
2.2 氨氧化功能基因amoA多样性及其影响因素6
2.2.1 氨氧化细菌群落α多样性分析6
2.2.2 氨氧化细菌群落β多样性分析8
2.2.3 氨氧化细菌群落组成分析8
2.3 氨氧化细菌群落多样性影响因素分析9
3 讨论10
3.1 不同围垦年限对土壤理化性质的影响10
3.2 不同围垦年限对土壤硝化作用的影响10
3.3 不同围垦年限对氨氧化微生物群落的影响11
4 结论11
致谢11
参考文献15
海陆界面农田土壤氨氧化微生物演变规律及其主控因素
摘 要
硝化作用指铵态氮在多种微生物作用下氧化成硝酸盐的过程。硝化作用的初始步骤由氨氧化微生物驱动完成，是氮素循环中的关键限速步骤，进入土壤中的氮肥至少经过一次氨氧化过程。课题通过采集杭州湾南岸垂直海岸带方向不同利用年限下的盐渍化水稻土，以NH4SO4 为底物进行室内培养，利用流动分析仪测定其中的NO3N量，明确海陆界面农田土壤硝化强度分布规律。其次，通过高通量测序技术分析土壤氨氧化细菌（AOB）的群落结构，揭示海陆界面土壤氨氧化微生物演变规律。最后，结合土壤理化性质，找出影响氨氧化微生物变化的主要因素。结果表明，随围垦年限延长，土壤pH呈下降趋势，由碱性逐渐偏向中性，盐分也呈降 *51今日免费论文网|www.51jrft.com +Q: ￥351916072$ 
低趋势；有机质则随着围垦年限延长增加。高通量测序结果分析可得，所有可注释的OUT都被划分到亚硝化螺菌属（Nitrosospira）和亚硝化单胞菌属（Nitrosomonas）属β变形菌纲（Betaproteobacteria），是典型氨氧化细菌。在滨海土壤被围垦后，氨氧化微生物群落多样性都有所降低。随着土壤理化性质的变化，一些β变形菌纲的氨氧化微生物可能不适应环境改变，从而导致其占比随围垦年限的延长而呈现降低趋势。
THE EVOLUTION AND CONTROLLING FACTORS of AMMONIAOXIDIZING MOCROORGANISM at THE SEALAND INERFACE
ABSTRACT
Nitrification refers to the process in which ammonium nitrogen is oxidized to nitrate under the action of various microorganisms. The initial stage of nitrification is driven by ammoniaoxidizing microorganisms and is a key ratelimiting step in the nitrogen cycle. Nitrogen fertilizer entering the soil undergoes at least one ammoniaoxidizing process. By collecting saline paddy soil with different utilization years in the vertical coastal zone on the south coast of Hangzhou Bay, the subject was cultivated indoors with NH4SO4 as the substrate, and the NO3N content was measured using a flow analyzer to clarify the distribution law of farmland soil nitrification intensity at sealand interface. Secondly, the highthroughput sequencing technology was used to analyze the community structure of soil ammoniaoxidizing bacteria (AOB) to reveal the evolution of soil ammoniaoxidizing microorganisms at the sealand interface. Finally, combined with the physical and chemical properties of the soil, the main factors affecting the changes of ammoniaoxidizing microorganisms were identified. The results show that with the extension of the years of reclamation, the soil pH decreases, the alkalinity gradually turns to neutral, and the salinity also decreases. Organic matter increased with the extension of the years of reclamation. All annotable OUT can be classified into Nitrosospira and Nitrosomonas, Betaproteobacteria, which are typical ammoniaoxidizing bacteria. After the coastal soil was reclaimed, the diversity of ammoniaoxidizing microbial community decreased. With the change of soil physical and chemical properties, some ammonium oxidizing microorganisms of the βproteobacteria may not adapt to changes in the living environment, resulting in a decreasing trend with the extension of reclamation period.

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