
植物营养与肥料学报2013,19(1):82-92 Plant Nutrition and Fertilizer Science
doi: 10. 11674/zwyf. 2013. 0110
太湖地区长期不同施肥水稻土N,和CO,
固定细菌群落结构的特征与差异
靳振江12,潘根兴1*,刘晓雨",李恋卿(1南京农业大学农业资源与生态环境研究所,江苏南京210095; 2桂林理工大学环境科学与工程学院,广西桂林541004)
摘要:土壤N,固定细菌和CO,固定细菌是土壤碳氮循环重要的微生物群落,不同施肥下土壤有机碳积累与这两类微生物群落结构及活性的关系有助于了解施肥对农田碳氮循环的影响特点。本文研究了太潮地区自1987年开始的水稍土长期施肥试验,选取不施肥(NF)、氮磷钾(NPK)肥(CF)、NPK肥与猪类配施(CFM)和NPK肥与秸秆还田配施(CFS)小区,采集(0—20cm)表层样本,以nijH和cbbLR基因分别作为N,和CO,固定细菌的指示基因,用 PCR-DGGE和荧光定量PCR的方法研究二者的群落结构,并用平板菌落计数法测定土壤自生周氮细菌数量和用乙炔还原法测定土壤固氮酶活性。结果表明,与CF处理相比,CF、CFM和CFS处理下的自生固氮细菌数量分别提高了58%、66%和106%;CF、CFM和CFS处理下的nj/H基因丰度分别提高了213%、1079%和344%。CF与CFM 处理的土壤固氮酶活性显著高于NF和CFS处理。因此,施肥提高了cbbLR基因的多样性。与NF处理相比,CF、 CFM和CFS处理下的cb6LR基因率度分别提高了465%、1827%和758%。相关性分析表明,土壤自生固氮菌数量与土壤有机碳含量呈显著正相关,cbLR和nijH基因丰度均与归一化的土壤养分量极其显著正相关。研究表明,有
机/无机肥配施下土壤养分平衡对维持N,和CO,固定细菌较高的丰度具有重要的作用。关键词:施肥;N,固定;CO,围定;细菌群落;养分平衡;有机碳
中图分类号:S154.3
文献标识码:A
文章编号:1008505X(2013)01008211
Community structure characters and differences of N,-fixing and CO,-fixing bacteria under long-term fertilization in paddy soils of Taihu Lake region, China
JIN Zhen-jiang'-2, PAN Gen-xing', LIU Xiao-yu', LI Lian-qing
(I Institute of Agricultural Resoturces, Ecosystem and Enrironment, Nanjing Agricultural University, Nanjing 210095, China 2 Cllege of Enrironmental Engineering and Science, Guilin Unitersity of Technology, Guilin, Guangxi 541004, China)
Abstract: Both CO,-fixing and N,-fixing bacteria are important microbes involved in soil carbon and nitrogen cycles, respectively. It is helpful for us to know the effect of fertilization on carbon and nitrogen cycles in farmland soils and to analyze the relationship between the soil organic carbon (SOC) and community structures of N,-fixing and CO,-fixing bacteria. The topsoil (O20 cm) samples were collected from a paddy field under a long-tem different fertilization trials initiated in 1987 from Taihu Lake region, China. There were four treatments, no fertilizer application (NF), application of NPK fertilizers only (CF), combined application of NPK fertilizers and pig manure (CFM) and combined application of NPK fertilizers and straw retum (CFS). Community structures were analyzed using PCR-DGGE and real-time PCR with nifH gene and cbLR gene as indicators of N,-fixing and CO,-fixing bacteria, respectively. Cloning forming unit (CFU) of autotrophic azotobacter was evaluated using plating colony-counting method. Nitrogenase activity was detected using acetylene reduction method as well. The results show that the abundances of njfH gene in the CF treatment, CFM treatment and CFS treatment are increased
收稿日期:2012-0716
接受日期:20120926
基金项目:国家自然科学基金重点项目(40830528);国家自然科学基金委国际合作重大项目(40710019002)资助。作者简介:新频江(1974一),男,山西长治人,博士研究生,副教投,主要从事生态学和环境微生物学方面的研究。
E-mail: zhenjiangjinjin@163, com。
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+ 通信f作者 E-mail: pangernxing yahoo. com, cn, E-mail; gxpan@ sjau. edu. cn