长期施肥酸性旱地土壤硝化活性及自养硝化微生物特征

发布时间：2018-08-20 16:48

【摘要】：构建微域培养结合梯度凝胶电泳(DGGE)、Illumina MiSeq高通量测序、生物信息学分析等分子生态学技术,以不施肥土壤为对照(CK),研究长期施化肥(NPK)和有机肥(OM)对酸性旱地土壤硝化活性及自养硝化微生物群落的影响,并认知其与土壤理化因子间的关系.结果表明,施化肥和有机肥显著提高土壤有机碳和无机氮含量,施有机肥提高土壤pH和总氮含量、降低C/N;供试土壤自养硝化作用占据主导(73.60%~85.32%),施肥显著提升土壤自养硝化活性,且施有机肥提升效果更为明显;微域培养后,OM土壤氨氧化古菌(AOA)和细菌(AOB)amoA基因绝对丰度及16S rRNA基因相对丰度显著上升,而CK和NPK土壤仅AOA相对丰度显著上升,即3种土壤AOA均有明显活性(主要类群为Nitrososphaera,99.30%),而AOB仅在OM土壤有活性(主要类群为Nitrosospira,99.99%),另外还发现OM土壤中亚硝酸盐氧化细菌(NOB)有较强活性(主要类群为Nitrospira,96.69%);逐步回归分析显示自养硝化活性显著受总氮含量影响,AOA和AOB amoA基因丰度分别受有机碳含量和pH影响,Nitrososphaera相对丰度与NO_3~--N含量显著正相关,而Nitrosospira和Nitrospira相对丰度则与C/N显著负相关.可见,长期施肥后土壤总氮含量的提升显著刺激自养硝化活性;以Nitrososphaera为主的AOA在酸性旱地土壤硝化作用中发挥了重要作用,施有机肥土壤pH上升及C/N下降刺激了Nitrosospira(AOB)生长,从而改变了酸性旱地土壤中活跃的自养硝化微生物类群.
[Abstract]:Microdomain culture combined with high throughput sequencing and bioinformatics analysis of (DGGE) Illumina MiSeq by gradient gel electrophoresis (GGE) was developed. The effects of long-term application of chemical fertilizer (NPK) and organic fertilizer (OM) on nitrification activity and autotrophic microorganism community in acidic dryland soil were studied by using non-fertilized soil as control (CK), and the relationship between them and soil physical and chemical factors was recognized. The results showed that the application of chemical fertilizer and organic fertilizer significantly increased soil organic carbon and inorganic nitrogen content, increased soil pH and total nitrogen content, and decreased C / N content, and soil autotrophic nitrification was dominant (73.60%), and fertilization significantly increased soil autotrophic nitrification activity. After microculture, the absolute abundance of (AOA) and bacterial (AOB) amoA gene and the relative abundance of 16s rRNA gene increased significantly, while the relative abundance of AOA in CK and NPK soil increased significantly. That is to say, all the three soil AOA have obvious activity (the main group is Nitrososphaera 99.30%), while AOB is only active in OM soil (the main group is Nitrosospiraium 99.99%). In addition, it is also found that the nitrite oxidizing bacteria (NOB) in OM soil has strong activity (the main group is Nitrospira96.69%), and the main group is Nitrospira96.69%, and the main group is Nitrospira96.69%. The results showed that autotrophic nitrification activity was significantly affected by total nitrogen content. AOA and AOB amoA gene abundance were positively correlated with NO_3~--N content by organic carbon content and pH, respectively. The relative abundance of Nitrosospira and Nitrospira was negatively correlated with C / N. It can be seen that the increase of soil total nitrogen content after long-term fertilization significantly stimulates the autotrophic nitrification activity, and AOA, which is dominated by Nitrososphaera, plays an important role in nitrification in acidic dryland soils, and the increase of soil pH and the decrease of C / N in organic fertilizer soil stimulate the growth of Nitrosospira (AOB). Thus the active autotrophic nitrification microflora in acid dryland soil was changed.
【作者单位】：南京师范大学地理科学学院江苏省物质循环与污染控制重点实验室;南京师范大学环境学院;江西省红壤研究所;
【基金】：国家自然科学基金项目(41401293,41271255) 江苏省自然科学基金项目(BK20141051) 国家重点研发计划项目(2016YFD0200302) 江苏高校优势学科建设工程资助项目
【分类号】：S154.3

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