鄱阳湖湿地剖面土壤微生物群落结构及功能的变化特征
发布时间：2019-06-11 20:10
【摘要】：鄱阳湖湿地是我国最大的天然淡水湖泊湿地,季节性水位动态明显,微地形复杂多变,拥有丰富的自然资源,随着人们对湿地功能性认识的不断高,鄱阳湖区湿地生态系统研究近年来受到学者们的普遍关注。对湿地土壤剖面的研究示,深层土壤中可能蕴含有大量的微生物资源,对湿地生态系统的物质转化和能量循环具有重要影响。然而对于微生物群落的结构组成、功能、代谢活性如何随着深度剖面分布,主要受何种因素影响,我们知之甚少且缺乏系统研究。因此,本研究以鄱阳湖湿地土壤为研究对象,样地选择在蚌湖(BH)、常湖池(CHC)、南矶山(东湖)(NJS)等三个典型区,取样土壤剖面深度为1m,分为5层(0-20cm、20-40cm、40-60cm、60-80cm、80-100cm)。采用16S rRNA高通量测序、q-PCR、Biolog-ECO等多样研究方法,对土壤理化性质、胞外酶活性、碳源代谢活性、微生物生物量以及细菌丰富度和群落结构进行分析。以阐明鄱阳湖湿地土壤微生物群落结构及代谢功能的空间变化,尤其是沿土壤剖面深度的变化特征,为多微生物组学角度示土壤演变机制供一条新的途径。结果表明:(1)鄱阳湖湿地土壤主要优势菌门为绿弯菌门(30.83%),其次是变形菌门(21.37%)和酸杆菌门(18.85%)。在更细的分类层次——科水平,主要的优势物种是Anaerolineaceae(17.49%),其次是Acidobacteriaceae_(Subgroup_1)(9.36%)和HSB_OF53-F07(8.00%)。与此同时,鄱阳湖湿地土壤细菌丰度(1.60×108-7.49×1010 copies/g)和Chao1指数(663-2664)也高于其它淡水湿地生态系统。使用METAGENassist进行基于细菌群落的代谢功能预测,结果显示:表层(0-20cm)土壤中细菌群落的代谢功能主要包括硫酸盐的还原(41.9%),氨氧化(35.8%),亚硝酸盐的还原(33.3%),脱卤(27.7%),硫化物的氧化(25.8%),木聚糖降解(20.1%),氮的固定(11.0%)等;深层(20-100cm)土壤中细菌群落的代谢功能主要包括氨氧化(37.7%),硫酸盐的还原(34.3%),亚硝酸盐的还原(27.8%),硫化物的氧化(25.7%),脱卤(22.9%),甲烷氧化(20.0%),木聚糖降解(18.7%)。(2)鄱阳湖湿地土壤细菌丰度及群落结构沿土壤剖面深度显著改变,且差异性主要表现在表层(0-20cm)土壤和深层(20-100cm)土壤之间,其中绿弯菌门、变形菌门以及酸杆菌门在湿地土壤剖面深度上有显著的差异性。细菌群落代谢功能方面,反硝化功能(7.0%)和储存聚羟基丁酸酯的功能(0.02%)只存在于表层土壤,而萘降解(0.9%)和硒酸盐还原剂功能(0.04%)只存在于深层土壤中。值得注意的是,深层土壤中的甲烷氧化功能(20.00%)明显的高于表层土壤(0.08%)。进一步研究发现,尽管在不同的样地间,土壤细菌群落结构存在显著的差异,但差异性远不及深度上的差异显著。(3)鄱阳湖湿地土壤微生物功能特性(微生物生物量、胞外酶活性、碳源代谢功能)显著受到土壤深度的影响,表层(0-20cm)土壤中微生物活性最高,土壤深度达到60cm以后,微生物活性开始稳定,但深层土壤中仍然进行着由微生物参与的复杂代谢活动。此外,仅微生物碳源代谢活性(AWCD)在样地间存在差异,土壤微生物生物量、胞外酶活性不随样地而发生改变,表明土壤微生物作为环境变化的敏感指标,其群落结构的改变会优先于某些代谢功能的改变,以此来应对外界环境的变化。(4)通过相关性分析以及冗余分析(RDA)发现,鄱阳湖湿地土壤微生物功能特性和细菌群落结构组成主要受到土壤有机质(AFDM)及营养元素(TOC、TN)的影响,除此之外,土壤含水量(SM)也是影响因素之一。其中AFDM、TOC和TN沿土壤剖面深度显著减小是导致鄱阳湖湿地土壤微生物的功能活性以及细菌群落结构随土壤剖面深度变化的主要原因;土壤SM在样地间的差异性,则使得土壤微生物碳源代谢活性及细菌群落结构随样地不同而发生改变。(5)通过相关性分析以及冗余分析发现,Bradyrhizobiaceae、4-29、Xanthobacteraceae与β-木糖苷酶(Bxyl)、过氧化物酶(Pero)、β-葡萄糖苷酶(Bglu)和土壤磷酸酶(Phos)的活性变化存在紧密的联系,Spirochaetaceae与乙酰氨基葡萄糖苷酶(NAG)的活性变化相关。Acidothermaceae、1921-3、HSB_OF53-F07、Cystobacteraceae、sh765B-TzT-35是影响碳源代谢活性的最主要物种。综上所述,鄱阳湖湿地土壤性质、土壤细菌群落结构、细菌丰富度和功能特性均随着深度表现出显著的差异,而在水平距离上差异并不明显。与深层土壤(20-100cm)相比,尽管表层土壤(0-20cm)微生物的功能更为活跃,细菌丰度高,但是深层土壤(甚至到100cm深度)仍然具有复杂的细菌群落组成和较高的代谢功能活性,这一点与其他生态系统中土壤微生物的垂直分布不太一致。这就示我们在湿地生态系统中,不同深度的土壤微生物具有不同的群落组成和代谢功能,深层土壤的微生物在土壤演化中的作用值得关注。本研究的结果初步揭示了鄱阳湖湿地土壤微生物的空间分布规律,深化了我们对于湿地生态系统的认识。全面的、系统的了解湿地生态系统,是湿地环境治理、资源保护、可持续发展的重要科学基础。本项目特色:首次采用较先进的研究手段,系统研究了鄱阳湖湿地土壤微生物群落结构和功能特性的空间分布,为预测鄱阳湖湿地生态系统微生物的演化趋势和功能活性供参考;较早的引入METAGENassist,将16S rRNA的高通量测序结果与群落代谢功能相联系,帮助进一步了解湿地土壤沿剖面变化的土壤微生物的功能多样性和重要性。
[Abstract]:Poyang Lake wetland is the largest natural freshwater lake wetland in China, the seasonal water level is dynamic, the micro-terrain is complex and changeable, has rich natural resources, The study of the wetland ecosystem in the Poyang Lake area has been widely concerned by the scholars in recent years. The study of the wetland soil profile shows that the deep soil may contain a large amount of microbial resources, which has an important effect on the material transformation and energy circulation of the wetland ecosystem. However, for the structure, function and metabolic activity of the microbial community, we know little about the influence of the distribution of the depth profile, and we know little about the system. Therefore, in this study, the soil of Poyang Lake wetland is used as the research object, and three typical areas such as the freshwater mussel (BH), the Changlaway (CHC) and the NJS (NJS) are selected. The depth of the sampling soil is 1 m, which is divided into 5 layers (0-20 cm,20-40 cm,40-60 cm,60-80 cm,80-100 cm). The soil physical and chemical properties, the extracellular enzyme activity, the carbon source metabolic activity, the microbial biomass and the bacterial richness and the community structure were analyzed by a variety of methods such as 16S rRNA high-throughput sequencing, q-PCR, Biolog-ECO and the like. The spatial variation of the structure and the metabolic function of the soil microbial community in the wetland of Poyang Lake, especially the change of the depth of the soil profile, is used to illustrate the soil evolution mechanism for a new route. The results showed that: (1) The main dominant bacteria in the wetland of Poyang Lake were the green lobacter (30.83%), followed by the strain (21.37%) and the acid bacteria (18.85%). The main dominant species were Anabaena (17.49%), followed by Acinetobacter _ (Subgroup _ 1) (9.36%) and HSB _ OF53-F07 (8.00%) at a finer level of classification. At the same time, the bacterial abundance (1.60-108-7.49-1010 copies/ g) and Chao1 index (663-2664) of the wetland in Poyang Lake are also higher than other freshwater wetland ecosystems. The results showed that the metabolic function of the bacterial community in the surface layer (0-20 cm) mainly includes the reduction of sulfate (41.9%), the ammonia oxidation (35.8%), the reduction of nitrite (33.3%) and the dehalogenation (27.7%). The oxidation of the sulfide (25.8%), the degradation of the xylan (20.1%), the fixation of nitrogen (11.0%), etc. The metabolic function of the bacterial community in the deep (20-100 cm) soil mainly includes ammoxidation (37.7%), reduction of sulfate (34.3%), reduction of nitrite (27.8%), Sulphide oxidation (25.7%), dehalogenation (22.9%), methane oxidation (20.0%), and xylan degradation (18.7%). (2) The soil bacterial abundance and community structure of the wetland in Poyang Lake are significantly changed along the soil profile, and the difference is mainly between the soil of the surface layer (0-20cm) and the deep layer (20-100 cm), among which, There was a significant difference in the depth of the soil profile of the wetland. In the aspects of bacterial community metabolism, the function of denitrification (7.0%) and the function of storing polyhydroxybutyrate (0.02%) only existed in the surface soil, while the function of microbial degradation (0.9%) and the function of the selenate reducing agent (0.04%) only existed in the deep soil. It is worth noting that the methane oxidation function (20.00%) in the deep soil is significantly higher than the surface soil (0.08%). Further studies have found that, although there is a significant difference in the structure of the soil bacterial community in different plots, the difference is far from that of the depth. (3) The microbial activity (microbial biomass, extracellular enzyme activity and carbon source metabolism) of the wetland in Poyang Lake was significantly affected by the depth of the soil, and the microbial activity was the highest in the surface layer (0-20 cm) and the soil depth reached 60 cm, and the microbial activity started to be stable. However, the deep soil still carries out complex metabolic activities involving the participation of microorganisms. in addition, only that metabolic activity of the microbial carbon source (AWCD) exist in the sample, the microbial biomass of the soil and the activity of the extracellular enzyme do not change with the sample, indicating that the soil microorganism is a sensitive index of environmental change, and the change of the community structure can take precedence over the change of certain metabolic functions, So as to cope with the change of the external environment. (4) The effect of soil organic matter (AFDM) and nutrient elements (TOC, TN) on the soil microbial function and the structure of the bacterial community was found by the correlation analysis and the redundancy analysis (RDA). In addition, Soil moisture content (SM) is also one of the influencing factors. in which the depth of the AFDM, TOC and TN is significantly reduced along the soil profile, resulting in the functional activity of the soil microorganisms in the Poyang Lake wetland and the main cause of the change of the bacterial community structure with the depth of the soil profile; the difference between the soil SM and the sample ground, The metabolic activity of the soil microbial carbon source and the structure of the bacterial community are changed along with the sample. (5) The activity changes of brayrhizobaiacae,4-29, Xanthomonas campestris (Bxyl), peroxidase (Pero), tomato-grape-glucoamylase (Bglu) and soil phosphatase (Pcos) have a close relationship through the correlation analysis and the redundancy analysis. The activity of Spirochaetacei was related to the activity of glycosaminoglucanase (NAG). Acdothermolaceae,1921-3, HSB _ O53-F07, Cysteobacter, sh765B-TzT-35 are the main species that affect the metabolic activity of the carbon source. In conclusion, the soil properties of the Poyang Lake wetland, the structure of the bacterial community of the soil, the richness of the bacteria and the functional characteristics of the wetland show a significant difference with the depth, and the difference in the horizontal distance is not obvious. Compared with the deep soil (20-100 cm), although the function of the surface soil (0-20cm) is more active and the bacterial abundance is high, the deep soil (even to the depth of 100 cm) still has complex bacterial community composition and higher metabolic function activity, This is not consistent with the vertical distribution of soil microorganisms in other ecosystems. This shows that in the wetland ecosystem, the soil micro-organisms at different depths have different community composition and metabolic functions, and the role of the micro-organisms in the deep soil is of great concern in the soil evolution. The results of this study preliminarily reveal the spatial distribution of soil microorganisms in Poyang Lake wetland and deepen our understanding of the wetland ecosystem. Comprehensive and systematic understanding of wetland ecosystem is an important scientific basis for wetland environmental management, resource protection and sustainable development. This project is characterized by the first use of advanced research means, the spatial distribution of the structure and functional characteristics of the soil microbial community in the wetland of Poyang Lake is systematically studied, and the evolution trend and function activity of the micro-organisms in the wetland ecosystem of Poyang Lake are provided for reference; and the earlier introduction of METAGENE, The high-throughput sequencing results of the 16S rRNA are associated with the community metabolic function to help further understand the functional diversity and importance of the soil microorganisms in the wetland soil along the profile.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S154.3
本文编号：2497418
[Abstract]:Poyang Lake wetland is the largest natural freshwater lake wetland in China, the seasonal water level is dynamic, the micro-terrain is complex and changeable, has rich natural resources, The study of the wetland ecosystem in the Poyang Lake area has been widely concerned by the scholars in recent years. The study of the wetland soil profile shows that the deep soil may contain a large amount of microbial resources, which has an important effect on the material transformation and energy circulation of the wetland ecosystem. However, for the structure, function and metabolic activity of the microbial community, we know little about the influence of the distribution of the depth profile, and we know little about the system. Therefore, in this study, the soil of Poyang Lake wetland is used as the research object, and three typical areas such as the freshwater mussel (BH), the Changlaway (CHC) and the NJS (NJS) are selected. The depth of the sampling soil is 1 m, which is divided into 5 layers (0-20 cm,20-40 cm,40-60 cm,60-80 cm,80-100 cm). The soil physical and chemical properties, the extracellular enzyme activity, the carbon source metabolic activity, the microbial biomass and the bacterial richness and the community structure were analyzed by a variety of methods such as 16S rRNA high-throughput sequencing, q-PCR, Biolog-ECO and the like. The spatial variation of the structure and the metabolic function of the soil microbial community in the wetland of Poyang Lake, especially the change of the depth of the soil profile, is used to illustrate the soil evolution mechanism for a new route. The results showed that: (1) The main dominant bacteria in the wetland of Poyang Lake were the green lobacter (30.83%), followed by the strain (21.37%) and the acid bacteria (18.85%). The main dominant species were Anabaena (17.49%), followed by Acinetobacter _ (Subgroup _ 1) (9.36%) and HSB _ OF53-F07 (8.00%) at a finer level of classification. At the same time, the bacterial abundance (1.60-108-7.49-1010 copies/ g) and Chao1 index (663-2664) of the wetland in Poyang Lake are also higher than other freshwater wetland ecosystems. The results showed that the metabolic function of the bacterial community in the surface layer (0-20 cm) mainly includes the reduction of sulfate (41.9%), the ammonia oxidation (35.8%), the reduction of nitrite (33.3%) and the dehalogenation (27.7%). The oxidation of the sulfide (25.8%), the degradation of the xylan (20.1%), the fixation of nitrogen (11.0%), etc. The metabolic function of the bacterial community in the deep (20-100 cm) soil mainly includes ammoxidation (37.7%), reduction of sulfate (34.3%), reduction of nitrite (27.8%), Sulphide oxidation (25.7%), dehalogenation (22.9%), methane oxidation (20.0%), and xylan degradation (18.7%). (2) The soil bacterial abundance and community structure of the wetland in Poyang Lake are significantly changed along the soil profile, and the difference is mainly between the soil of the surface layer (0-20cm) and the deep layer (20-100 cm), among which, There was a significant difference in the depth of the soil profile of the wetland. In the aspects of bacterial community metabolism, the function of denitrification (7.0%) and the function of storing polyhydroxybutyrate (0.02%) only existed in the surface soil, while the function of microbial degradation (0.9%) and the function of the selenate reducing agent (0.04%) only existed in the deep soil. It is worth noting that the methane oxidation function (20.00%) in the deep soil is significantly higher than the surface soil (0.08%). Further studies have found that, although there is a significant difference in the structure of the soil bacterial community in different plots, the difference is far from that of the depth. (3) The microbial activity (microbial biomass, extracellular enzyme activity and carbon source metabolism) of the wetland in Poyang Lake was significantly affected by the depth of the soil, and the microbial activity was the highest in the surface layer (0-20 cm) and the soil depth reached 60 cm, and the microbial activity started to be stable. However, the deep soil still carries out complex metabolic activities involving the participation of microorganisms. in addition, only that metabolic activity of the microbial carbon source (AWCD) exist in the sample, the microbial biomass of the soil and the activity of the extracellular enzyme do not change with the sample, indicating that the soil microorganism is a sensitive index of environmental change, and the change of the community structure can take precedence over the change of certain metabolic functions, So as to cope with the change of the external environment. (4) The effect of soil organic matter (AFDM) and nutrient elements (TOC, TN) on the soil microbial function and the structure of the bacterial community was found by the correlation analysis and the redundancy analysis (RDA). In addition, Soil moisture content (SM) is also one of the influencing factors. in which the depth of the AFDM, TOC and TN is significantly reduced along the soil profile, resulting in the functional activity of the soil microorganisms in the Poyang Lake wetland and the main cause of the change of the bacterial community structure with the depth of the soil profile; the difference between the soil SM and the sample ground, The metabolic activity of the soil microbial carbon source and the structure of the bacterial community are changed along with the sample. (5) The activity changes of brayrhizobaiacae,4-29, Xanthomonas campestris (Bxyl), peroxidase (Pero), tomato-grape-glucoamylase (Bglu) and soil phosphatase (Pcos) have a close relationship through the correlation analysis and the redundancy analysis. The activity of Spirochaetacei was related to the activity of glycosaminoglucanase (NAG). Acdothermolaceae,1921-3, HSB _ O53-F07, Cysteobacter, sh765B-TzT-35 are the main species that affect the metabolic activity of the carbon source. In conclusion, the soil properties of the Poyang Lake wetland, the structure of the bacterial community of the soil, the richness of the bacteria and the functional characteristics of the wetland show a significant difference with the depth, and the difference in the horizontal distance is not obvious. Compared with the deep soil (20-100 cm), although the function of the surface soil (0-20cm) is more active and the bacterial abundance is high, the deep soil (even to the depth of 100 cm) still has complex bacterial community composition and higher metabolic function activity, This is not consistent with the vertical distribution of soil microorganisms in other ecosystems. This shows that in the wetland ecosystem, the soil micro-organisms at different depths have different community composition and metabolic functions, and the role of the micro-organisms in the deep soil is of great concern in the soil evolution. The results of this study preliminarily reveal the spatial distribution of soil microorganisms in Poyang Lake wetland and deepen our understanding of the wetland ecosystem. Comprehensive and systematic understanding of wetland ecosystem is an important scientific basis for wetland environmental management, resource protection and sustainable development. This project is characterized by the first use of advanced research means, the spatial distribution of the structure and functional characteristics of the soil microbial community in the wetland of Poyang Lake is systematically studied, and the evolution trend and function activity of the micro-organisms in the wetland ecosystem of Poyang Lake are provided for reference; and the earlier introduction of METAGENE, The high-throughput sequencing results of the 16S rRNA are associated with the community metabolic function to help further understand the functional diversity and importance of the soil microorganisms in the wetland soil along the profile.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S154.3
【参考文献】
相关期刊论文 前10条
1 隋心;张荣涛;杨立宾;许楠;钟海秀;王继丰;倪红伟;;三江平原不同类型小叶章湿地土壤细菌群落功能多样性[J];环境科学研究;2016年10期
2 王鹏;陈波;张华;;基于高通量测序的鄱阳湖典型湿地土壤细菌群落特征分析[J];生态学报;2017年05期
3 陈熙;刘以珍;李金前;葛刚;吴兰;李永绣;;稀土尾矿土壤细菌群落结构对植被修复的响应[J];生态学报;2016年13期
4 马晓飞;楚新正;马倩;;艾比湖地区融雪期梭梭和柽柳林地土壤酶活性研究[J];中国农学通报;2016年14期
5 李艳红;葛刚;王茂林;周晓岚;胡春华;;垂向归纳模型下鄱阳湖丰、枯水期初级生产力特征及与环境因子相关性分析[J];湖泊科学;2016年03期
6 韩晓君;;三江平原湿地生态系统保护研究进展[J];黑龙江水利科技;2016年04期
7 杨英;耿玉清;黄桂林;赵恒毅;周红娟;;青海小泊湖区沼泽化草甸、草甸和沙地的土壤酶活性[J];湿地科学;2016年01期
8 王金爽;胡泓;李甜甜;李正炎;吕向梨;;环境因素对湿地土壤微生物群落影响研究进展[J];湿地科学与管理;2015年04期
9 蒋绍妍;王文星;薛向欣;徐坤;;利用PCR-DGGE分析茂名油页岩矿区土壤细菌群落组成[J];中南大学学报(自然科学版);2015年12期
10 隋心;张荣涛;钟海秀;许楠;王继丰;刘应竹;袁海峰;倪红伟;;利用高通量测序对三江平原小叶章湿地土壤细菌多样性的研究[J];土壤;2015年05期
相关博士学位论文 前2条
1 陈伟;纳帕海高原湿地微生物多样性研究[D];昆明理工大学;2016年
2 贾玉华;坡面土壤水分时空变异的试验研究[D];中国科学院研究生院（教育部水土保持与生态环境研究中心）;2013年
相关硕士学位论文 前5条
1 张祖芳;鄱阳湖湿地生态功能重要性分区研究[D];南昌大学;2014年
2 国春菲;土壤盐分和pH对滨海盐土土壤微生物多样性的影响[D];浙江农林大学;2013年
3 陈会海;三江湿地土壤微生物群落结构的多样性分析[D];东北农业大学;2013年
4 胡维;鄱阳湖南矶山湿地土壤微生物群落结构的时空变化特点研究[D];南昌大学;2012年
5 孟晗;长三角地区土壤不同发育阶段微生物群落结构的变化[D];复旦大学;2011年
，本文编号：2497418
本文链接：https://www.wllwen.com/kejilunwen/nykj/2497418.html
