Changes of Bacterial Community Structure in Copper Mine Tailings After Colonization of Reed （Phragmites communis）

Soil samples were collected from both bare and vegetated mine railings to study the changes in bacterial communities and soil chemical properties of copper mine tailings due to reed （Phragmites communis） colonization. The structures of bacterial communities were investigated using culture-independent 16S rRNA gene sequencing method. The bacterial diversity in the bare mine tailing was lower than that of the vegetated mine tailing. The former was dominated by sulfur metabolizing bacteria, whereas the latter was by nitrogen fixing bacteria. The bare mine tailing was acidic （pH = 3.78）, whereas the vegetated mine tailing was near neutral （pH ： 7.28）. The contents of organic matter, total nitrogen, and ammonium acetate-extractable potassium in vegetated mine tailings were significantly higher than those in the bare mine railings （P 〈 0.01）, whereas available phosphorus and electrical conductivity were significantly lower than those in the bare mine tailings （P 〈 0.01）. The results demonstrated that 16S rRNA gene sequencing could be successfully used to study the bacterial diversity in mine tailings. The colonization of the mine tailings by reed significantly changed the bacterial community and the chemical properties of tailings. The complex interactions between bacteria and plants deserve further investigation.     

铜尾矿污染土壤几种牧草的重金属抗性及微生物群落功能多样性研究

Copper （Cu） mine tailings, because of their high content of heavy metals, are usually hostile to plant colonization. A pot experiment was conducted to determine the tolerance of four forage grasses to heavy metals in Cu mine tailings and to examine the variation in the microbial functional diversity of soils from the tailing sites in southern China. All the four grass species survived on Cu mine tailings and Cu mine tailing-soil mixture. However, on pure mine tailings, the growth was minimal, whereas the growth was maximum for the control without mine tailings. The tolerance of grasses to heavy metals followed the sequence： Paspalum notatum 〉 Festuea arundinaeea 〉 Lolium perenne 〉 Cynodon daetylon. The planting of forage grasses enhanced the soil microbial biomass. The Biolog data indicated that the soil microbial metabolic profile values （average well color development, community richness, and Shannon index） of the four forage grasses also followed the sequence： P. notatum 〉 F. arundinaeea 〉 L. perenne 〉 C. daetylon. Thus, P. notatum, under the experimental conditions of this study, may be considered as the preferred plant species for revegetation of Cu mine tailing areas.     

利用Illumina高通量测序对复合重金属污染下根际和非根际稻田土壤细菌的研究

There is an increasing concern about rice (Oryza sativa L.) soil microbiomes under the influence of mixed heavy metal contamination.We used the high-throughput Illumina MiSeq sequencing approach to explore the bacterial diversity and community composition of soils in four paddy fields,exhibiting four degrees of mixed heavy metal (Cd,Pb and Zn) pollution,and examined the effects of these metals on the bacterial communities.Our results showed that up to 2 104 to 4 359 bacterial operational taxonomic units (OTUs) were found in the bulk and rhizosphere soils of the paddy fields,with the dominant bacterial phyla (greater than 1％ of the overall community) including Proteobacteria,Actinobacteria,Firmicutes,Acidobacteria,Gemmatimonadetes,Chloroflexi,Bacteroidetes and Nitrospirae.A number of rare and candidate bacterial groups were also detected,and Saprospirales,HOC36,SC-I-84 and Anaerospora were rarely detected in rice paddy soils.Venn diagram analysis showed that 174 bacterial OTUs were shared among the bulk soils with four pollution degrees.Rice rhizosphere soils displayed higher bacterial diversity indices (ACE and Chao 1) and more unique OTUs than bulk soils.Total Cd and Zn in the soils were significantly negatively correlated with ACE and Chao 1,respectively,and the Mantel test suggested that total Pb,total Zn,pH,total nitrogen and total phosphorus significantly affected the community structure.Overall,these results provided baseline data for the bacterial communities in bulk and rhizosphere soils of paddy fields contaminated with mixed heavy metals.     

Long-time precipitation reduction and nitrogen deposition increase alter soil nitrogen dynamic by influencing soil bacterial communities and functional groups

The effects of precipitation reduction and nitrogen deposition increase on soil bacterial communities and functions impact soil nitrogen cycling. Seasonal changes could modify the effects of precipitation reduction and nitrogen deposition increase on bacterial communities and functions by changing soil environments and properties. Understanding soil microbial communities and the seasonal response of functions to precipitation reduction and nitrogen deposition increase may be important for the accurate prediction of changes in the soil nitrogen dynamics. Thus, a long-term field simulation experiment of nitrogen deposition increase and throughfall exclusion was established to investigate soil bacterial communities’ response to nitrogen deposition increase and/or precipitation reduction, with no nitrogen deposition increase and no precipation reduction as a control, in a temperate forest. We examined soil bacterial communities (Illumina sequencing) under different treatments during the winter, freezing-thawing cycle periods (FTCs), and growing season. The bacterial functional groups were predicted by the FAPROTAX database. The results showed that nitrogen deposition increase, precipitation reduction, the combined effect of nitrogen deposition increase and precipitation reduction, and seasonal changes significantly altered the soil bacterial community composition. Interestingly, by combining the result of a previous study in which nitrogen deposition increase increased the nitrous oxide flux in the same experimental system, the loss of soil nitrogen was increased by the decrease in denitrification and increase of nitrification bacteria under nitrogen deposition increase, while ammonification bacteria significantly increased and N-fixing bacteria significantly decreased with precipitation reduction compared to the control. In relation to seasonal changes, the aromatic-degrading, cellulolytic, and ureolytic bacteria were lowest during FTCs, which indicated that FTCs might inhibit biodegradation. Nitrification and nitrite-oxidizing bacteria increased with nitrogen deposition increase or precipitation reduction and in FTCs compared to the control or other seasons. The interaction between treatment and season significantly changed the soil bacterial communities and functions. These results highlight that nitrogen deposition increase, precipitation reduction, seasonal changes, and their interactions might directly alter bacterial communities and indirectly alter the dynamics of soil N.     

盐沼湿地中植物根围土壤细菌群落结构和多样性的16S rDNA分析

The structure and diversity of the bacterial communities in rhizosphere soils of native Phragmites australis and Scirpus rnariqueter and alien Spartina alterniflora in the Yangtze River Estuary were investigated by constructing 16S ribosomal DNA （rDNA） clone libraries. The bacterial diversity was quantified by placing the clones into operational taxonomic unit （OTU） groups at the level of sequence similarity of 〉 97%. Phylogenetic analysis of the resulting 398 clone sequences indicated a high diversity of bacteria in the rhizosphere soils of these plants. The members of Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria of the phylum Proteobacteria were the most abundant in rhizobacteria. Chao 1 nonpaxametric diversity estimator coupled with the reciprocal of Simpson＇s index （l/D） was applied to sequence data obtained from each library to evaluate total sequence diversity and quantitatively compare the level of dominance. The results showed that Phragmites, Scirpus, and Spartina rhizosphere soils contained 200, 668, and 382 OTUs, respectively. The bacterial communities in the Spartina and Phragraites rhizosphere soils displayed species dominance revealed by 1/D, whereas the bacterial community in Scirpus rhizosphere soil had uniform distributions of species abundance. Overall, analysis of 16S rDNA clone libraries from the rhizosphere soils indicates that the changes in bacterial composition may occur concomitantly with the shift of species composition in plant communities.     

不同改良剂对黑麦草在铜矿尾矿砂上生长的影响

Montmorillonite, rice straw, organic manure and chemical fertilizer were used as amendment materials for copper mine tailings, and their effects on mine tailing pH, nutrients and metal availability to ryegrass were investigated. Chemical fertilization was the most effective one in improving ryegrass growth in mine tailings among the amendment materials examined. It was found that montmorillonite raised biomass of ryegrass at the 1st and 2nd cuts, but it did not give further positive effects at the 3rd and 4th cuts. The effect of organic materials on ryegrass growth was not so good as expected, mainly due to their slow decomposition in mine tailings with less soil microorganisms. Available Cu and Zn contents in mine tailings decreased in the presence of montmorillonite but increased when rice straw and organic manure were used as amendments. Cu and Zn contents in ryegrass decreased with increasing the rate of montmorillonite application but increased with the rate of rice straw. Zn showed much stronger mobility from soil to ryegrass than Cu, and almost all the available N and P in mine tailings, except for the treatments with organic manure, were completely consumed after ryegrass had grown in mine tailings for more than four months and been harvested for four times. Owing to its large biomass and high metal uptake, ryegrass is a potential plant for remediation of metal contaminated soils in practice.     

中国长江三角洲地区一新石器时代水稻土细菌群落

An ancient irrigated paddy soil from the Neolithic age was excavated at Chuodunshan Site in the Yangtze River Delta, close to Suzhou, China. The soil organic matter (SOM) content in the prehistoric rice soil is comparable to the average SOM content of present rice soils in this region, but it is about 5 times higher than that in the parent materials. As possible biomarkers to indicate the presence of the prehistoric paddy soil, the bacterial communities were investigated using the techniques of aerobic and anaerobic oligotrophic bacteria enumeration, Biolog analysis, and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that in the buried soil layers, the prehistoric paddy soil had the largest number of aerobic and anaerobic oligotrophic bacteria, up to 6.12 and 5.86 log cfu g-1 dry soil, respectively. The prehistoric paddy soil displayed better carbon utilization potential and higher functional diversity compared to the parent materials and a prehistoric loess layer. The Shannon index and richness based on DGGE profiles of bacterial 16S rRNA genes were higher in prehistoric paddy soil than those in the prehistoric loess soil. It might be concluded that the prehistoric irrigated rice cultivation accumulated the SOM in plowed soil layer, and thus increased soil bacterial populations, metabolic activity, functional diversity and genetic diversity. Bacterial communities might be considered as the sensitive indicators of the presence of the prehistoric paddy soil in China’s Yangtze River Delta.     

Revegetation of copper mine tailings with ryegrass and willow

To restore vegetation on metal mine tailings is very difficult because they often contain high concentrations of heavy metals, low nutrient content and low water retention capacity. This study involved 3 experiments that evaluated the effects of 4 treatment amendments: montmorillonite, rice straw, organic manure and chemical fertilizer on the growth of ryegrass (Loliurn perenne L.) and willow (Salix virninalis L.) with Cu and Zn mine tailings from two mining areas. The results showed that ryegrass was the most tolerant of 4 crops to Cu toxicity. Also when organic manure, which contained high concentrations of inorganic salts, was added to the mine tailings, it significantly hindered ryegrass growth (P=0.05).Meanwhile, with ryegrass organic manure significantly increased (P=0.05) the extractable Cu concentration in both mine tallings. When montmorillonite was used as a mine tailings amendment with willow, the height and tress number at the 1st cut were significantly greater (P = 0.05) than a control without montmorillonite. However there was no significant difference for height, tress number, dry weight or root dry weight at the 2nd cut. So, amendment applications to reduce metal toxicity and increase nutrients retention in mine tailings were essential during revegetation of mine tailings.     

Soil properties and habitats determine the response of bacterial communities to agricultural wastewater irrigation

Increasing temperatures and variability of precipitation events due to climate change will lead in the future to higher irrigation demands in agroecosystems.However,the use of secondary treated wasterwater(TWW)could have consequences for the receiving soil environment and its resident microbial communities.The objective of this study was to characterize the importance of soil properties and habitats to the response of soil bacteria and archaea to irrigation with TWW.Two agricultural soils with contrasting textures(loamy sand or silt loam)and,for each,three variants differing in soil organic carbon and nitrogen,as generated by long-term fertilization,were analyzed.For each of these six soils,prokaryotic communities from two habitats,i.e.,root-free bulk soil and the rhizosphere of developing cucumber plants in the greenhouse,were characterized.Communities were analyzed by the quantity and diversity of their polymerase chain reaction(PCR)-amplified 16S rRNA genes.To account for TWW-associated nutrient effects,potable water(PW)served as a control.Amplicon sequence analysis showed that prokaryotic communities mainly consisted of bacteria(99.8%).Upon irrigation,regardless of the water quality,prokaryotic diversity declined,p H increased,and no bacterial growth was detected in bulk soil.In contrast,the growth of cucumbers was stimulated by TWW,indicating that plants were the main beneficiaries.Moreover,strong responses were seen in the rhizosphere,suggesting an indirect effect of TWW by altered rhizodepositions.The main bacterial responders to TWW were Proteobacteria,Bacteroidetes,Actinobacteria,and Planctomycetes.Changes in bacterial communities due to TWW were less pronounced in all variants of the silt loam,indicating the importance of clay and soil organic carbon for buffering effects of TWW on soil bacterial communities.Hence,soil organic carbon and soil texture are important parameters that need to be considered when applying TWW in agriculture.     

接种溶磷真菌对玉米和大豆根际细菌群落结构多样性的影响

Application of phosphate-solubilizing microorganisms （PSMs） has been reported to increase P uptake and plant growth. However, no information is available regarding the ecological consequences of the inoculation with PSMs. The effect of inoculation with phosphate-solubilizing fungal （PSF） isolates Aspergillus niger P39 and Penicillium oxalicum P66 on the bacterial communities in the rhizospheres of maize （Zea mays L. ‘Haiyu 6＇） and soybean （Glycine max Merr. ‘Heinong 35＇） was examined using culture-dependent methods as well as a culture-independent method, polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE）. Compared with the control, the number of culturable microbes for soybean was significantly greater with P39, whereas for maize, the same was significantly greater with P66. In addition, a greater number of microbes were found in the rhizosphere of maize compared with soybean. The fingerprint of DGGE for 16S rDNA indicated that inoculation with PSF also increased bacterial communities, with the P66 treatment having higher numbers of DGGE bands and a higher Shannon-Weaver diversity index compared with P39; the composition of the microbial community was also more complex with the P66 treatment. Overall, complex interactions between plant species and exotic PSMs affected the structure of the bacterial community in the rhizosphere, but plant species were more important in determining the bacterial community structure than the introduction of exotic microorganisms.     

Changes of Bacterial Community Structure in Copper Mine Tailings After Colonization of Reed (Phragmites communis)

Soil samples were collected from both bare and vegetated mine tailings to study the changes in bacterial communities and soil chemical properties of copper mine tailings due to reed (Phragmites communis) colonization. The structures of bacterial communities were investigated using culture-independent 16S rRNA gene sequencing method. The bacterial diversity in the bare mine tailing was lower than that of the vegetated mine tailing. The former was dominated by sulfur metabolizing bacteria, whereas the latter was by nitrogen fixing bacteria. The bare mine tailing was acidic (pH = 3.78), whereas the vegetated mine tailing was near neutral (pH = 7.28). The contents of organic matter, total nitrogen, and ammonium acetate-extractable potassium in vegetated mine tailings were significantly higher than those in the bare mine tailings (P< 0.01), whereas available phosphorus and electrical conductivity were significantly lower than those in the bare mine tailings (P< 0.01). The results demonstrated that 16S rRNA gene sequencing could be successfully used to study the bacterial diversity in mine tailings. The colonization of the mine tailings by reed significantly changed the bacterial community and the chemical properties of tailings. The complex interactions between bacteria and plants deserve further investigation.     

不同修复植被类型的三峡库区消落带土壤细菌群落分析

为了探究三峡库区消落带不同修复植被对土壤细菌群落结构的影响,以纯草地(A₁)、纯林地(A₂)和覆草林地(A₃)3种不同样地土壤为研究对象,采用土壤理化因子检测及扩增子测序的研究方法,分析了不同修复植被对三峡库区消落带土壤细菌群落的影响。结果表明:不同样地的pH值、全氮(TN)和全磷(TP)含量无显著性差异,A₁和A₃的土壤有机碳(SOC)含量之间无显著性差异,但均显著高于A₂(p<0.05); 相关分析显示样地土壤细菌群落ACE指数和Shannon指数与土壤SOC和TN含量显著正相关(p<0.05),Chao1指数与土壤SOC含量显著正相关(p<0.05); 不同样地土壤的细菌优势种群无明显区别; 属水平上6个优势种群的相对丰度与土壤SOC和TN含量显著相关(p<0.05); 冗余分析显示SOC是影响三峡库区消落带不同修复植被样地细菌群落的主要显著性因子(p<0.05)。由此可以得出,不同修复植被类型的消落带土壤的细菌优势种群无明显差异,土壤细菌群落结构主要受土壤SOC的影响。     

不同秸秆还田方式对旱地红壤细菌多样性及群落结构的影响

为明确不同秸秆还田方式下土壤细菌群落结构变化特征，以南方典型旱地红壤为研究对象，基于中国科学院鹰潭红壤生态实验站玉米单作系统不同秸秆还田方式的长期试验，利用高通量测序明确了不同秸秆还田方式对土壤细菌多样性及群落结构的影响。结果表明：1）秸秆还田对土壤肥力提升显著，以秸秆猪粪配施（NPKSM）提升效果最佳；2）常规化肥处理（NPK）对细菌多样性无显著影响，但秸秆还田（NPKS）、秸秆猪粪配施（NPKSM）以及生物质炭（NPKB）处理均显著提升土壤细菌多样性；3）速效磷（AP）和土壤有机碳（SOC）变化是影响细菌多样性指数的主要因素，而速效钾（AK）、pH、总磷（TP）以及总氮（TN）均显著驱动细菌群落结构变异。研究结果从培育红壤肥力与微生物多样性的角度，为农业生态系统生物功能和土壤健康的协同提升提供了科学依据。     

球等鞭金藻三级培养过程中细菌群落多样性分析

球等鞭金藻三级培养过程中生长差异明显,在完全灭菌的一级培养中生长最佳,在未灭菌的三级培养中生长最差。为揭示培养过程中藻际细菌群落多样性与其生长差异的相关性,以球等鞭金藻(Isochrysis galbana)为研究对象,利用Illumina HiSeq平台通过高通量测序的方法对球等鞭金藻三级培养过程中细菌群落多样性进行研究。结果表明,一、二、三级培养组之间的藻际细菌群落组成差异明显。Shannon和Simpson指数分析说明,一级培养组中细菌群落多样性显著低于二级和三级培养组。MetaStat分析发现,一级和三级培养组之间存在两株丰度显著差异的细菌,其中麦氏交替单胞菌(Alteromonas macleodii)在三级培养下丰度显著高于一级,而红球菌(Rhodococcus erythropolis)相反。进一步通过2216E平板涂布法分离并鉴定了麦氏交替单胞菌等17株球等鞭金藻藻际环境细菌;系统进化树构建结果显示,整个进化树分成13个分支,分别对应13个属,包括交替单胞属(Alteromonas)、假交替单胞属(Pseudoalteromonas)、海杆菌属(Marinobacter)等。本研究结果为探索藻菌互作机理奠定了基础,有助于提高水产养殖过程中球等鞭金藻的产量和质量。     

甘蔗宿根矮化病感病与非感病株根际土壤生物学性状及细菌群落结构特征

[目的]比较甘蔗宿根矮化病(ratoon stunting disease,RSD)感病植株与非感病植株根际土壤的生物学性状及细菌群落结构特征,旨在为构建甘蔗健康的根际微环境,筛选高效RSD生防细菌提供参考。[方法]通过田间调查和实验室鉴定,以甘蔗RSD感病植株为试材,非感病植株为对照,采集甘蔗RSD感病植株和非感病植株的根际土壤,并基于传统和现代高通量测序技术,分析了甘蔗RSD感病植株和非感病植株根际土壤的生物学性状和细菌群落结构特征。[结果]与甘蔗RSD非感病植株相比,感病植株根际土壤中指示土壤肥力与健康状况的生物学性状指标β-葡糖苷酶、磷酸酶和氨肽酶活性,以及微生物生物量碳、氮、磷显著降低;同时,指示细菌丰富度的Chao1指数和指示细菌多样性的Shannon指数显著下降。门分类水平与非感病甘蔗植株相比,RSD感病植株根际土壤中Proteobacteria(变形杆菌门)、Actinobacteria(放线菌门)、Gemmatimonadetes(芽单胞菌门)和Nitrospirae(硝化螺旋菌门)等优势门类细菌占比呈倍级降低,但Chloroflexi(绿弯菌门)、Acidobacteria(酸杆菌门)、Firmicutes(厚壁菌门)、Cyanobacteria(蓝细菌门)、Planctomycetes(浮霉菌门)、Bacteroidetes(拟杆菌门)等优势门类细菌占比呈倍级增加;在属分类水平,与非感病甘蔗植株相比,RSD感病植株根际土壤中Xanthobacteraceae(黄色杆菌属)、Acidothermus、Gaiellales、Roseiflexus(玫瑰菌属)、Micromonosporaceae(小单孢菌属)和Nitrospira(硝化螺旋菌属)细菌占比呈倍级降低,但Acidobacteria(嗜酸菌属)细菌及部分未知菌属却呈倍级提高。[结论]甘蔗RSD感病植株根际微环境中指示土壤肥力的生物学指标显著降低,细菌丰富度和多样性显著下降,部分优势细菌门属占比发生剧变可能是导致甘蔗RSD发生的重要原因。     

川西北不同沙化程度草地土壤细菌群落特征

研究川西北不同沙化程度草地（未沙化草地、轻度沙化草地、中度沙化草地、重度沙化草地）土壤细菌多样性和群落结构特征,利用Illumina二代高通量测序技术MiSeq对土壤细菌的16 SrRNA V₃—V₄可变区进行测序,研究土壤细菌多样性、物种组成和丰富度,并结合土壤理养分探讨影响细菌群落结构的环境因素,对发挥土壤潜在肥力,了解土壤健康状况,实现该区植被的管理与可持续利用有着重要的意义。结果表明:（1）不同沙化草地土壤养分具有明显差异,依次表现为:随着沙化程度的增加,土壤pH值逐渐增加,而土壤有机碳、全氮、全钾、碱解氮和速效磷逐渐降低;（2）不同沙化程度草地土壤样品中共检测到细菌的32个门,65个纲,169个目,优势菌门为变形菌门（Proteobacteria）、放线菌门（Actinobacteria）、酸杆菌门（Acidobacteria）、绿弯菌（Chloroflexi）、浮霉菌门（Planctomycetes）,主要的优势菌纲为放线杆菌纲（Actinobacteria）、α-变形菌纲（α-Proteobacteria）、酸杆菌纲（Acidobacteria）、β-变形菌纲（β-Proteobacteria）、浮霉菌纲（Planctomycetacia）,与沙化草地相比,未沙化草地优势菌主要是变形菌门（Proteobacteria）和放线菌门（Actinobacteria）;（3）随着沙化程度的增加,OUT数目、Chao指数、Ace指数、Shannon指数逐渐减小,其中不同沙化草地土壤细菌覆盖率和Simpson指数差异不显著（p > 0.05）;（4）冗余分析和Pearson相关性分析表明,土壤pH值、土壤有机碳（SOC）和全氮（TN）是土壤细菌群落结构和多样性的主要影响因子。     

枣园生草处理对土壤养分和细菌群落的影响

为了明确枣园种植长柔毛野豌豆(Vicia villosa Roth.)对土壤养分和细菌群落的影响,本试验以5年生金丝4号(Zizyphus jujuba Mill.)为试材,研究了枣园不同生草处理(清耕、自然生草、长柔毛野豌豆)对土壤基本理化指标和土壤细菌群落的影响.结果表明,与清耕(对照)相比,枣园生草提高了 土壤含...     

Alphaproteobacteria communities depend more on soil types than land managements

Soil properties and agricultural practices take a joint effect on the communities of soil bacteria. The aim of the present study was to survey Alphaproteobacterial communities as possible indicators of soil quality considering clay, loamy and sandy soils under conventional and organic farming. Alphaproteobacteria community composition were analysed by 16S rRNA gene with nested-PCR (polymerase chain reaction) and denaturing gradient gelelectrophoresis (DGGE). Sequencing of partial 16S rRNA gene from the DGGE bands were performed. Conventional and organic farming resulted in significant differences in chemical properties of soils. According to the results community fingerprints were separated into groups depending on soil types and farming systems. This separation can be attributed mostly to soil pH, AL-P₂O₅,-K₂O. The analysed sequences were identified as soil bacteria which could play the main role in nitrogen fixing, mineralisation and denitrification. The highest diversity index was revealed from the organic farming at sandy texture site, where mainly Mesorhizobium sp. and Rhizobium sp. were detected. The soil type and actual crop could have a stronger impact on the soil bacterial composition than the management.     

连作对再植枸杞根际细菌群落多样性和群落结构的影响研究

受枸杞道地产区土地资源等因素限制,连作障碍已成为影响枸杞产业发展的重要原因之一,导致严重的经济损失.研究连作条件下枸杞农田土壤生态系统微生物群落的演替规律对枸杞产业的可持续发展具有重要的理论意义.以宁夏银川市南梁农场连作多年的枸杞地为研究对象,利用Illumina MiSeq测序技术分析了连作对再植枸杞根际/非根际细菌群落的影响.结果表明,连作地显著抑制再植枸杞苗地径的增加,且其土壤pH较对照样地显著降低(p<0.05).测序结果证实,与对照样地相比,连作地再植枸杞根际土壤细菌物种数显著降低(p<0.05),细菌群落α多样性下降(p>0.05).主坐标分析表明,连作和对照样地间枸杞非根际细菌群落结构无明显差异,但连作显著改变再植枸杞根际细菌的群落结构.对细菌群落丰度的统计分析发现,连作地枸杞根际浮霉菌门、非根际假单胞菌门的相对丰度较对照样地显著降低(p<0.05).此外,冗余分析结果表明:枸杞园土壤pH和有效磷含量是影响枸杞非根际土壤细菌群落结构变化的主要因素,分别解释了41.8%和35.4%的群落结构变化(p<0.05),其他土壤因子无统计学意义,但土壤理化因子对再植枸杞根际细菌群落结构变化的影响均未达显著水平.这些结果证实连作能够显著抑制再植枸杞生长、影响再植枸杞根际细菌群落结构和多样性,干扰枸杞与土壤细菌群落间的互作关系.这些研究结果将为解析枸杞连作障碍机制提供理论基础.