施氮对冬种紫云英不还田条件下稻田土壤微生物数量与结构的影响  

Effects of nitrogen application on the abundance and community of soil microbes in paddy field under the condition of no returning Chinese milk vetch

作　　者：聂江文 王幼娟 吴邦魁 刘章勇[1] 朱波[1] NIE Jiang-wen;WANG You-juan;WU Bang-kui;LIU Zhang-yong;ZHU Bo(Yangtze University,Engineering Research Center of Ecology and Agricultural Use of Wetland,Ministry of Education/Hubei Key Laboratory of Waterlogging Disaster and Wetland Agriculture,Jingzhou 434025,Hubei,China)

机构地区：[1]长江大学湿地生态与农业利用教育部工程研究中心/湖北省涝渍灾害与湿地农业重点实验室,湖北荆州434025

出　　处：《生态学杂志》2018年第12期3617-3624,共8页Chinese Journal of Ecology

基　　金：十三五国家重点研发计划粮食丰产增效工程(2016YFD0300208);国家自然科学基金项目(31501274);湖北省教育厅优秀中青年科技创新团队(T201404);主要粮食作物产业化湖北省协同创新中心开放基金项目(2015MS001);中国科协青年人才托举工程项目(YESS20160040)资助

摘　　要：揭示长期不同施肥制度对稻田土壤微生物的影响,为农田优化施肥和耕作制度提供理论依据。采用Illumina MiSeq高通量测序平台和荧光定量PCR技术,研究湖南省双季稻区连续8年不施肥(CK)以及冬种紫云英不还田条件下3种氮肥水平(N0、N100、N200)对紫云英盛花期土壤微生物群落数量和结构的影响。结果表明,与CK相比,冬种紫云英不还田配施氮肥显著降低土壤pH、硝态氮及土壤碳氮比(C/N),显著提高稻田土壤全氮、有机质和铵态氮含量。稻田土壤微生物数量在1.66×10~8～1.23×10^(10)拷贝数·g^(-1)干土,施肥均增加16S rDNA基因丰度,N0、N100、N200三种施肥水平处理的16S rDNA基因拷贝数分别是CK的1.0、74.4、32.6倍。3种氮肥水平处理的多样性指数(香农指数与辛普森指数)以及物种丰富度指数(Ace与Chao1)均高于CK,其中多样性指数最高的是N200,物种丰富度最高的是N100。不同样品16S rDNA的门水平分类的3个主要类群是变形菌门(Proteobac-teria)、绿弯菌门(Chloroflexi)和硝化螺旋菌门(Nitrospirae),分别占总OTU比例的33%～44.4%、17%～22.3%和9%～10%;N0、N100和N200土壤样品中变形菌门(Proteobacteria)和硝化螺旋菌门(Nitrospirae)的相对丰度均低于CK,而N0、N100和N200土壤样品中绿弯菌门(Chloroflexi)的相对丰度分别是CK的1.2、1.3和1.2倍。相关性分析表明,细菌16SrDNA基因拷贝数与土壤有机质、土壤总氮和铵态氮含量显著相关;土壤细菌菌群与多数土壤化学指标间存在密切的相关性。综上,冬种紫云英不还田施氮肥显著增加水稻产量和紫云英盛花期土壤微生物数量,改变土壤微生物菌群结构,改善了土壤化学性质,对湖南双季稻区科学合理种植绿肥具有指导意义。Understanding the impacts of long-term fertilization regimes on soil microbial ecology in paddy field can provide theoretical basis for optimal fertilization and farming.Here,an 8-year experiment was conducted to examine the effects of N application levels (NO,N100,N200) under the condition of no returning milk vetch in winter on the abundance and structure of soil microbial community during the flowering of milk vetch in a double cropping system in Hunan Province.Soil microbes were quantified using Illumina MiSeq high-throughput sequencing plat- form and fluorescence quantitative PCR technique.The results showed that soil pH,nitrate con- tent and soil C/N ratio significantly decreased with increasing N application level under the con- dition of no returning milk vetch in winter.Moreover,N fertilization significantly increased the contents of total N,soil organic carbon and ammonium N in paddy soil.The microbial quantity in paddy field was 1.66x10S-l.23x10^10copies·g-1 dry soil.N fertilization increased the 16S rDNA gene abundance,and the copy number of 16S rDNA gene in NO,N100and N200fertilization treatments was 1.0,72.4and 32.6times of that in CK,respectively.The diversity index (Shan- non index and Simpson index)and species richness index (Ace and Chaol )of the three N ferti- lization treatments were higher than those of CK,among which N200had the highest diversity in- dex and N100hand the highest species richness.Three major taxonomic groups of 16S rDNA in different samples were Proteobacteria,Chloroflexi and Nitrospirae,which accounted for 33%- 44.4%,17%-22.3%and 9%-10%of the total OTU,respectively.The relative abundance of Proteobacteria and Nitrospirae in NO,N100and N200soil samples was lower than that of CK, while the relative abundance of Chloroflexia in NO,N100and N200was 1.2,1.3and 1.2times of CK,respectively.Correlation analysis showed that the copy number of bacterial 16S rDNA gene was significantly correlated with soil organic carbon,total N and ammonium contents.There was a close correlation betwe

关 键 词：冬种紫云英不还田 氮肥水平 土壤微生物 高通量测序 荧光定量PCR 

分 类 号：S154.3[农业科学—土壤学]