南方典型母质发育稻田土壤氨氧化细菌和古菌群落结构特征

Community Structure Characteristics of Ammonia-oxidizing Bacteria and Archaea in Paddy Soil with Different Parent Materials in Southern China

摘要:

依托中国科学院桃源农业生态试验站水稻土易地置土长期定位试验，以广东英利(YL，发育于玄武岩风化物)、江西鹰潭(YT，发育于第四纪红黏土)和湖南桃源古市(TYG，发育于河流冲积物)3种母质发育稻田土壤为供试土壤，采用常规土壤农化分析方法测得3种土壤的理化性质、硝化速率，并结合实时荧光定量PCR技术和Illumina MiSeq测序技术，分析了土壤氨氧化古菌(AOA)和氨氧化细菌(AOB)种群丰度及群落结构的异同。结果表明：土壤硝化速率除分蘖期外，均表现为：YT>YL>TYG。YL与YT土壤中AOA数量占主导地位，AOA/AOB比值比值分别在0.72 ~ 3.05、0.98 ~ 1.52；TYG土壤中AOB数量占主导地位，AOA/AOB比值在0.21 ~ 0.75。群落组成方面，不同母质土壤间AOA、AOB群落结构差异显著，3种土壤AOA优势菌属各不相同，AOB优势菌属均为Nitrosospira。冗余分析表明，pH和可溶性有机碳是造成AOA、AOB群落结构差异的核心因子。综上，在环境背景均统一的前提下，不同母质发育稻田土壤理化性质之间依旧存在差异，这种差异影响着氨氧化微生物AOA、AOB的丰度以及群落结构。

Abstract:

Relying on the Long-term Positioning Experiment of Rice Soil Ex-situ Soil of the Taoyuan Agricultural Ecology Experimental Station of the Chinese Academy of Sciences, three paddy soils derived from different parent materials were selected from Yingli in Guangdong Province (YL, basalt weathering material), Yingtan in Jiangxi Province (YT, quaternary red clay material) and Taoyuan in Hunan Province (TYG, river alluvium material), physicochemical properties and nitrification rates were measured using conventional agrochemical soil analysis methods, and the similarities and differences in ammonia-oxidizing archaea(AOA) and ammonia-oxidizing bacteria(AOB)gene abundances and community structure were analyzed using real-time quantitative PCR and Illumina MiSeq sequencing. The results showed nitrification rate was presented as YT>YL>TYG except at tillering stage. And the abundance of AOA dominated in YL and YT, with AOA/AOB ratios between 0.72 and 3.05 and 0.98 and 1.52, respectively. In TYG, the abundance of AOB was dominant, with an AOA/AOB ratios between 0.21 and 0.75. Parent material has a significant influence on AOA and AOB community structure, the predominant genera were different in AOA while Nitrosospira dominant in AOB with three soils. The redundancy analysis (RDA) showed that pH and DOC were the most important factors influencing AOA and AOB community structure. In conclusion, there are differences in the physicochemical properties in paddy soils derived from different parent materials in the same environment, which affects the abundance and community structure of AOA and AOB.