EGI OpenIR  > 研究系统  > 荒漠环境研究室
极端干旱区几种典型多年生植物根际微生物群落特征研究
高欢欢
学位类型博士
导师曾凡江
2017-05-01
学位授予单位中国科学院大学
学位授予地点新疆乌鲁木齐
学位专业理学博士
关键词极端干旱区 根际微生物 群落多样性 植被修复 垂直空间尺度
摘要根际作为植物-土壤-微生物复合体,在土壤生态系统中最为活跃。植物通过根系与土壤、微生物发生偕同作用,共同作用于生态系统。根际微生物能在土壤-植物之间自由穿梭,参与能量转换与物质运输,在根际微环境中占据重要地位。由于受到气候变化和人类活动等因素的影响,极度干旱区的荒漠生态系统结构极其脆弱,并出现不同程度的退化。退化生态系统修复的主要措施之一是利用多年生优势植物进行植被恢复与重建。因此,系统研究和综合评价极端干旱区多年生植物根际微生物群落特征,对于退化生态系统修复具有重要的科学意义和应用价值。本研究依托中国科学院吐鲁番沙漠植物园和策勒荒漠草地生态系统国家野外研究站,通过自然条件下实验和人工控制实验,利用划线平板法、BIOLOG法、高通量测序、土壤化学元素分析法等相结合的方法,对几种典型多年生优势植物疏叶骆驼刺(Alhagi sparsifolia Shap.)、多枝柽柳(Tamarix ramosissima Ledeb.)、头状沙拐枣(Calligonum caput-medusae Schrenk.)的根际微生物群落特征及对生态系统修复的作用进行定位研究。结果表明:(1)在根际微生物生境特征方面:在自然环境实验中,植物种、土壤深度及其交互作用对根际土壤理化性质各指标都有极显著的影响。根际土壤含水率极低,各样品土壤含水率范围在1.01%~1.12%之间。三种植物根际土壤均呈现弱碱性,pH值范围在7.76~8.37。电导率(EC)大小排序:疏叶骆驼刺>多枝柽柳>头状沙拐枣。疏叶骆驼刺根际土壤C、N、C:P、N:P显著高于多枝柽柳和头状沙拐枣;根际土壤P含量从大到小依次为多枝柽柳>疏叶骆驼刺>头状沙拐枣;根际土壤C:N均值排序为:多枝柽柳>头状沙拐枣>疏叶骆驼刺。土壤深度与根际土壤C、P、C:P、N:P存在极显著相关性。(2)在微生物数量分布方面:研究发现细菌占根际可培养微生物数量中的多大多数。每种植物根际细菌数量、微生物总数在不同土层有相同的波动变化规律。根际真菌、放线菌在不同植物不同土层也呈现差异性分布。根际细菌数量、微生物总数排序为:头状沙拐枣>疏叶骆驼刺>多枝柽柳。根际真菌、放线菌数量排序为:疏叶骆驼刺>多枝柽柳>头状沙拐枣。除多枝柽柳、头状沙拐枣根际细菌、放线菌、微生物总数在0-50 cm和200-250 cm土层呈现负效应,其余样本根际效应均为正效应。(3)在微生物群落结构多样性方面:从所有样品中共获得根际细菌36门、77纲、105目、270科、1133属,获得根际真菌8门、727纲、87目、17科、439属,其中包含很多新的菌属。三种植物在较浅土层优势细菌菌门为放线菌门(Actinobacteria),随土壤深度的增加变形菌门(Proteobacteria)逐渐替代放线菌门(Actinobacteria)成为优势菌门。疏叶骆驼刺根际土壤优势细菌属为Pseudosphingobacterium,多枝柽柳和头状沙拐枣根际土壤优势细菌属均为拟无枝酸菌属(Amycolatopsis)。三种植物根际真菌优势菌门都是子囊菌门(Ascomycota)。疏叶骆驼刺根际真菌优势菌属是赤壳属(Nectria),多枝柽柳为桦褐孔菌属(Inonotus),头状沙拐枣为粉孢革菌属(Coniophora)。(4)在微生物功能多样性方面:根际微生物群落代谢平均颜色变化(AWCD值)排序为:疏叶骆驼刺>多枝柽柳>头状沙拐枣。其中疏叶骆驼刺根际微生物AWCD最高土层为100-150 cm,多枝柽柳为0-50 cm,头状沙拐枣为200-250 cm。AWCD值最高的土层,多样性指数H和多样性指数U值也最大。主成分分析共提取了8个主成分构成根际微生物功能代谢主要碳源,其中包含氨基酸4种、单糖3种、胺类2种、酸类2种、醇类1种共计12种碳源,主要碳源利用类型是氨基酸和单糖。(5)微生物数量与群落功能多样性对植被修复的响应:利用头状沙拐枣植被修复后土壤中细菌、放线菌数量、微生物总数比其他疏叶骆驼刺和多枝柽柳植被修复后多,利用疏叶骆驼刺植被修复后土壤中真菌数量最多。疏叶骆驼刺植被修复后土壤微生物代谢活性(AWCD值)最强,多枝柽柳植被修复后土壤微生物功能多样性最高。疏叶骆驼刺和多枝柽柳植被修复后中间土层微生物数量较多,头状沙拐枣植被修复后较深土层微生物数量较多。疏叶骆驼刺、头状沙拐枣植被修复后较深土层微生物代谢最强,多枝柽柳植被修复后中间土层微生物代谢最强。植被修复后荒漠土壤主要碳源利用类型是酸类与氨基酸类。
其他摘要Rhizosphere is an ecosystem that is involved in a variety of organisms. It is closely related to plant health and environmental sustainability, and is the most active part of the soil ecosystem. Plants act with roots and soil microbial function in the ecological system. Rhizosphere microorganisms play an important role in the rhizosphere microenvironment, which can move freely between the soil and plants, participate in the energy conversion and transport. Due to the influence of climate change and human activities, the structure of the desert ecosystem in the extreme arid region is extremely simple and fragile, and it is degraded to some extent. One of the main measures for the restoration of degraded ecosystems is the use of perennial dominant plants for vegetation restoration and reconstruction. Therefore, it is of great scientific significance and application value to systematically study and evaluate the characteristics of rhizosphere microbial community of perennial plants in extreme arid area.This study was based on Turpan Desert Botanical Garden and Cele National Station of Observation and Research for Grassland Ecosystem, Chinese Academy of Sciences. We carried this experiment under natural conditions and artificial control experiments, the method of using the method of streak plate method, BIOLOG method, high throughput sequencing, soil chemical element analysis and so on. We selected three kinds of perennial dominant plants-Alhagi sparsifolia, Tamarix ramosissima, Calligonum caput-medusae. Study on the characteristics of rhizosphere microbial community and its role in ecosystem restoration. The main results were as follows:(1) In the respect of the characteristics of rhizosphere habitat: In the experiment of natural environment, plant species, soil depth and their interaction had significant effects on the physical and chemical properties of rhizosphere soil. The moisture content of rhizosphere soil was very low, and the soil moisture content of each sample was between 1.01%~1.12%. The rhizosphere soil of three plants showed weak alkaline and the pH value was 7.76~8.37. Electrical conductivity (EC) size: A. sparsifolia> T. ramosissima > C. caput-medusae. The C, N, C: P and N: P in the rhizosphere soil of A. sparsifolia, was significantly higher than T. ramosissima and C. caput-medusae. Rhizosphere soil P content from large to small in turn was T. ramosissima > A. sparsifolia > C. caput-medusae, the C: N was T. ramosissima > C. caput-medusae > A. sparsifolia. There was a significant correlation between soil depth and rhizosphere soil C, P, C: P, N: P.(2) In the respect of microbial number distribution: The results showed that bacteria accounted for most of the number of culturable microorganisms in the rhizosphere. The number of bacteria and the total number of microorganisms in the rhizosphere of different plants had the same fluctuation in different soil layers. Rhizosphere fungi and actinomycetes showed different distribution in different soil layers. The number of rhizosphere bacteria, microbial total order: C. caput-medusae > A. sparsifolia > T. ramosissima. Rhizosphere fungi and actinomycetes as follows: A. sparsifolia > T. ramosissima > C. caput-medusae. In addition, the total number of rhizosphere bacteria, actinomycetes and microorganisms in T. ramosissima and C. caput-medusae were negative in 0-50 cm and 200-250 cm soil layers, and the rhizosphere effect was positive in the other samples. (3) In the respect of microbial community structure diversity: All the samples obtained from the rhizosphere bacteria of 36 phyla, 77 classes, 105 orders, 270 families and 1133 genera, obtain rhizosphere fungi of 8 door, 727 classes, 87 orders, 17 families and 439 genera, which contains many unnamed and newly discovered bacteria. The three species of the dominant bacteria in the shallow soil layer of the door for Actinobacteria. Along with the increase of soil depth, Proteobacteria gradually replaced the Actinobacteria as the dominant bacteria. Dominant bacteria of A.sparsifolia rhizosphere soil was Pseudosphingobacterium. Dominant soil bacteria of T. ramosissima and C. caput-medusae rhizosphere was Amycolatopsis. Dominant soil fungi of three plants rhizosphere was Ascomycota. Dominant genera of A. sparsifolia rhizosphere fungi was Nectria, Inonotus and Coniophora were dominant genera of T. ramosissima and C. caput-medusae respectively.(4) In the respect of microbial functional diversity: Rhizosphere AWCD value order: A. sparsifolia>T. ramosissima >C. caput-medusae. The highest AWCD value of the A. sparsifolia rhizosphere soil was 100-150 cm, 0-50 cm in T. ramosissima rhizosphere, and 200-250 cm in C. caput-medusae rhizosphere. The highest layer, diversity index H and diversity index U value is also the largest. Rhizosphere microbial metabolism mainly use 12 kinds of carbon sources, among them: 4 kinds of amino acids, 3 kinds of monosaccharide, 2 kinds of amines, 2 kinds of acids and 2 kind of alcohols. (5) Response of microbial quantity and community functional diversity to vegetation restoration: Afer vegetation restoration, the number of bacteria and actinomycetes and total microbial in C. caput-medusae culture pond were most, and soil in A. sparsifolia culture pond had the largest number of fungi. Value of soil microbial AWCD was the highest after vegetation restoration using A. sparsifolia and value of diversity index H and U index was highest after vegetation restoration using T. ramosissima. Microbial number in middle layer after vegetation restoration using A. sparsifolia and T. ramosissima was most, however, in the deepest layer using C. caput-medusae. The metabolic intensity functional diversity was highest in deeper layer after vegetation restoration using A. sparsifolia and C. caput-medusae, and in middle layer after vegetation restoration using T. ramosissima. The main types of soil carbon sources were acids and amino acids.
学科领域植物学
语种中文
文献类型学位论文
条目标识符http://ir.xjlas.org/handle/365004/14778
专题研究系统_荒漠环境研究室
作者单位中国科学院新疆生态与地理研究所
推荐引用方式
GB/T 7714
高欢欢. 极端干旱区几种典型多年生植物根际微生物群落特征研究[D]. 新疆乌鲁木齐. 中国科学院大学,2017.
条目包含的文件
条目无相关文件。
个性服务
推荐该条目
保存到收藏夹
查看访问统计
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[高欢欢]的文章
百度学术
百度学术中相似的文章
[高欢欢]的文章
必应学术
必应学术中相似的文章
[高欢欢]的文章
相关权益政策
暂无数据
收藏/分享
所有评论 (0)
暂无评论
 

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。