Diversity Of Rhizosphere Microbial Communities Research Articles

Effects of micro/nano-ozone bubble nutrient solutions on growth promotion and rhizosphere microbial community diversity in soilless cultivated lettuces.

Due to its high efficacy as a wide-spectrum disinfectant and its potential for the degradation of pollutants and pesticides, ozone has broad application prospects in agricultural production. In this study, micro/nano bubble technology was applied to achieve a saturation state of bubble nutrient solution, including micro-nano oxygen (O2 group) and micro-nano ozone (O3 group) bubble nutrient solutions. The effects of these solutions on lettuce physiological indices as well as changes in the microbial community within the rhizosphere substrate were studied. The application of micro/nano (O2 and O3) bubble nutrient solutions to substrate-cultured lettuce plants increased the amount of dissolved oxygen in the nutrient solution, increased the lettuce yield, and elevated the net photosynthetic rate, conductance of H2O and intercellular carbon dioxide concentration of lettuce plants. Diversity analysis of the rhizosphere microbial community revealed that both the abundance and diversity of bacterial and fungal communities in the substrate increased after plant cultivation and decreased following treatment with micro/nanobubble nutrient solutions. RDA results showed that the microbial community in the S group was positively associated with EC, that in the CK and O2 groups exhibited a positive correlation with SC, and that in the O3 group displayed a positive correlation with CAT and POD. Overall, the implementation of micro/nanobubble generation technology in soilless substrates can effectively increase the lettuce growth and yield, and O3 had a more pronounced effect on lettuce yield and quality and the microbial community structure in the substrate than O2. Our study would provide a reference and theoretical basis for developing sustainable and green technology for promoting lettuce production and can be a promising alternative to conventional methods for improving crop yields.

Characterization of Rhizosphere Microbial Diversity and Selection of Plant-Growth-Promoting Bacteria at the Flowering and Fruiting Stages of Rapeseed.

Plant rhizosphere microorganisms play an important role in modulating plant growth and productivity. This study aimed to elucidate the diversity of rhizosphere microorganisms at the flowering and fruiting stages of rapeseed (Brassica napus). Microbial communities in rhizosphere soils were analyzed via high-throughput sequencing of 16S rRNA for bacteria and internal transcribed spacer (ITS) DNA regions for fungi. A total of 401 species of bacteria and 49 species of fungi in the rhizosphere soil samples were found in three different samples. The composition and diversity of rhizosphere microbial communities were significantly different at different stages of rapeseed growth. Plant-growth-promoting rhizobacteria (PGPRs) have been widely applied to improve plant growth, health, and production. Thirty-four and thirty-one PGPR strains were isolated from the rhizosphere soil samples collected at the flowering and fruiting stages of rapeseed, respectively. Different inorganic phosphorus- and silicate-solubilizing and auxin-producing capabilities were found in different strains, in addition to different heavy-metal resistances. This study deepens the understanding of the microbial diversity in the rapeseed rhizosphere and provides a microbial perspective of sustainable rapeseed cultivation.

Combined application of microbial inoculant and kelp-soaking wastewater promotes wheat seedlings growth and improves structural diversity of rhizosphere microbial community

Industrial processing of kelp generates large amounts of kelp-soaking wastewater (KSW), which contains a large amount of nutrient-containing substances. The plant growth-promoting effect might be further improved by combined application of growth-promoting bacteria and the nutrient-containing KSW. Here, a greenhouse experiment was conducted to determine the effect of the mixture of KSW and Bacillus methylotrophicus M4-1 (MS) vs. KSW alone (SE) on wheat seedlings, soil properties and the microbial community structure in wheat rhizosphere soil. The available potassium, available nitrogen, organic matter content and urease activity of MS soil as well as the available potassium of the SE soil were significantly different (p < 0.05) from those of the CK with water only added, increased by 39.51%, 36.25%, 41.61%, 80.56% and 32.99%, respectively. The dry and fresh weight of wheat seedlings from MS plants increased by 166.17% and 50.62%, respectively, while plant height increased by 16.99%, compared with CK. Moreover, the abundance and diversity of fungi in the wheat rhizosphere soil were significantly increased (p < 0.05), the relative abundance of Ascomycetes and Fusarium spp. decreased, while the relative abundance of Bacillus and Mortierella increased. Collectively, the combination of KSW and the plant growth-promoting strain M4-1 can promote wheat seedlings growth and improve the microecology of rhizosphere microorganisms, thereby solving the problems of resource waste and environmental pollution, ultimately turning waste into economic gain.

Biochar Amendment Suppressed Fusarium Wilt and Altered the Rhizosphere Microbial Composition of Tomatoes

The effectiveness of biochar application to promote plant growth and suppress plant diseases is usually dependent on the application dose of the biochar. Here, we evaluated the effects of biochar supplied at 0%, 1%, 2%, and 3% (w/w) on tomato growth, Fusarium wilt disease severity, and rhizosphere microbial community diversity. We found that biochar applied at 1% and 2% promoted tomato growth and decreased the severity of Fusarium wilt disease. High-throughput amplicon sequencing indicated that 1% biochar decreased the alpha diversity and altered the composition of the bacterial and fungal community in the tomato rhizosphere, increasing the abundance of potential plant-beneficial microorganisms. Quantitative PCR confirmed that all doses of biochar increased the abundance of rhizosphere bacteria; biochar applied at 1% and 2% decreased the abundance of rhizosphere fungi and Fusarium oxysporum f. sp. Lycopersici (FOL), while biochar applied at 3% increased abundance of FOL. Our results indicated that biochar applied at 1% and 2% suppressed tomato Fusarium wilt disease, which might be linked to the change of the rhizosphere microbial community structure and increased the abundance of potential plant-beneficial microorganisms such as Pseudomonas sp. within the microbiome.

Metal uptake and translocation by Chinese brake fern (Pteris vittata) and diversity of rhizosphere microbial communities under single and combined arsenic and cadmium stress.

Chinese brake fern (Pteris vittata) can increase tolerance to arsenic (As) and cadmium (Cd) toxicity by regulating rhizosphere microbial diversity. However, effects of combined As-Cd stress on microbial diversity and plant uptake and transport remain poorly understood. Therefore, effects of different concentrations of As and Cd on Pteris vittata (P. vittata) metal uptake and translocation and rhizosphere microbial diversity were examined in a pot experiment. The results indicated that As primarily accumulated aboveground in P. vittata (bioconcentration factor (BCF) ≤ 51.3; translocation factor (TF) ≈ 4), whereas Cd primarily accumulated belowground (BCF ≤ 39.1; TF < 1). Under single As, single Cd, and As-Cd combined stress, the most dominant bacteria and fungi were Burkholderia-Caballeronia-P (6.62-27.92%) and Boeremia (4.61-30.42%), Massilia (8.07-11.51%) and Trichoderma (4.47-22.20%), and Bradyrhizobium (2.24-10.38%) and Boeremia (3.16-45.69%), respectively, and their abundance ratios had a significant impact on the efficiency of P. vittata for As and Cd accumulation. However, with increasing As and Cd concentrations, abundances of plant pathogenic bacteria such as Fusarium and Chaetomium (the highest abundances were 18.08% and 23.72%, respectively) increased, indicating that As and Cd concentrations reduced P. vittata resistance to pathogens. At high soil concentrations of As-Cd, although plant As and Cd contents increased and microbial diversity was highest, enrichment efficiency and transportability of As and Cd decreased substantially. Therefore, pollution intensity should be considered when evaluating P. vittata suitability for phytoremediation of combined As-Cd contaminated soils.

Poly-γ-glutamic acid promoted maize root development by affecting auxin signaling pathway and the abundance and diversity of rhizosphere microbial community

BackgroundThe root systems of higher plants play an important role in plant growth and development. In our present study, it was found that poly-γ-glutamic acid (γ-PGA), an environmentally friendly biomacromolecule, significantly improved root development in maize.ResultsAfter treatment with γ-PGA for 7 days, the fresh weight of maize roots was significantly increased and the differences between γ-PGA treated group and control group were mainly caused by the number (higher by 71.87% compared to the control) and length of lateral roots. RNAseq and RT-PCR analyses showed that γ-PGA treatment upregulated the expression of genes related to the synthesis of auxins and auxin signal in maize roots. In addition, γ-PGA promoted the accumulation of plant growth-promoting bacteria, such as Azospirillum, Azohydromonas, Ramlibacter, and Sphingobium (Proteobacteria), Streptomyces (Actinobacteria), Parasegetibacter (Bacteroidetes), and Gemmatimonas (Gemmatimonadetes) in rhizosphere soil and the secretion of auxins. The results of this study deepened our understanding of the effects and mechanism of γ-PGA on maize root development, and as well as highlighted the possibility of using γ-PGA to improve crop growth and soil environment.Conclusionsγ-PGA promotes early growth and development of maize roots by inducing the secretion and accumulation of auxin in roots and in rhizosphere soil, and increasing the abundance of plant growth promoting bacteria.

Composition and Structural Characteristics of Rhizosphere Microorganisms of Polygonum sibiricum (Laxm.) Tzvelev in the Yellow River Delta

The Polygonum sibiricum (Laxm.) Tzvelev, an important herbal species used to protect seawalls, has a solid resistance to salinity and alkali and can grow on alkali spots in saline–alkali soils. So far, the composition, population, and characteristics of its rhizosphere biological community related to the adaptation salt–alkali environment were still unknown. In the present study, rhizosphere and non-rhizosphere soil samples from the P. sibiricum on Chenier Island were collected. High-throughput sequencing was conducted to obtain the structural diversity of rhizosphere microbial communities. Our results showed that the dominant bacteria groups in the rhizosphere and non-rhizosphere were Proteobacteria, Actinobacteriota, Gemmatimonadota, and Actinobacteriota. The dominant fungi groups in the rhizosphere and non-rhizosphere soil samples were Ascomycota, Basidiomycota, Chytridiomycota, and Mortierellomycota. The results of the ASVs (amplicon sequence variants) showed that fungi have more ASVs in common. The PERMANOVA analysis showed that the bacteria among different groups were significantly different. The PCoA (principal coordinates analysis) study also showed that the structures of the bacterial and fungal communities between the rhizosphere and non-rhizosphere were distinct. Function results showed that the relative abundance in COG (Clusters of Orthologous Groups of proteins) functional annotation was significantly different between the two groups. In addition to the general function prediction and carbohydrate transport and metabolism, the COG of the non-rhizosphere was higher than that of the rhizosphere. Our findings benefited the knowledge for studying and conserving the molecule-level adaptive mechanisms of P. sibiricum.

Maize stalk rot caused by Fusarium graminearum alters soil microbial composition and is directly inhibited by Bacillus siamensis isolated from rhizosphere soil.

Maize stalk rot caused by Fusarium graminearum can reduce the yield of maize and efficiency of mechanized harvesting. Besides, deoxynivalenol and zearalenone toxins produced by F. graminearum can also affect domestic animals and human health. As chemical fungicides are expensive and exert negative effects on the environment, the use of biological control agents has become attractive in recent years. In the present study, we collected rhizosphere soil with severe stalk rot disease (ZDD), the rhizosphere soil with disease-free near by the ZDD (ZDH), and measured rhizosphere microbial diversity and microbial taxonomic composition by amplicon sequencing targeting either bacteria or fungi. The results showed that Fusarium stalk rot caused by the Fusarium species among which F. graminearum is frequent and can reduce the abundance and alpha diversity of rhizosphere microbial community, and shift the beta diversity of microorganisms. Furthermore, a bacterial strain, Bacillus siamensis GL-02, isolated from ZDD, was found to significantly affect growth of F. graminearum. In vitro and in vivo assays demonstrated that B. siamensis GL-02 had good capability to inhibit F. graminearum. These results revealed that B. siamensis GL-02 could be a potential biocontrol agent for the control of maize stalk rot.

Rhizosphere Microbial Community Diversity and Function Analysis of Cut Chrysanthemum During Continuous Monocropping.

As an ornamental flower crop, the long-term continuous monocropping of cut chrysanthemum causes frequent occurrence of diseases, seriously affecting the quality of cut chrysanthemum. The rhizosphere microbial community plays an important role in maintaining the healthy growth of plants, whereas the composition and dynamics of rhizosphere microbial community under continuous monocropping of cut chrysanthemum have not been fully revealed. In this study, the Illumina MiSeq high-throughput sequencing platform was used to monitor the dynamic changes of rhizosphere microbial communities in four varieties of cut chrysanthemum during 0–3 years of monocropping, and the soil physicochemical properties were also determined. Results showed that continuous monocropping significantly increased the fungal community richness and altered the profiles of the bacterial and fungal communities, leading to variation of community beta-diversity. With the increase of continuous cropping time, biocontrol bacteria decreased, while some plant pathogenic fungi were enriched in the rhizosphere of cut chrysanthemum. FAPROTAX-based functional prediction showed that the abundance of gene related to nitrogen and sulfur metabolism and chitin lysis was reduced in the rhizosphere of cut chrysanthemum. FUNGuild-based fungal function prediction showed that plant pathogenic fungal taxa were increasing in the rhizosphere of cut chrysanthemum, mainly Acremonium, Plectosphaerellaceae, Fusarium, and Cladosporium. Continuous cropping also reduced the content of ammonium nitrogen and increased soil salinity, resulting in deterioration of soil physical and chemical properties, which, together with the transformation of rhizosphere microbial community, became part of the reasons for the continuous cropping obstacle of cut chrysanthemum.

Effects of Plant Fine Root Functional Traits and Soil Nutrients on the Diversity of Rhizosphere Microbial Communities in Tropical Cloud Forests in a Dry Season

The composition and diversity of rhizosphere microbial communities may be due to root–soil–microbial interactions. The fine root functional traits and rhizosphere soil environmental factors of 13 representative plants in the Bawangling tropical cloud forest of Hainan Island were measured, to assess the key factors driving plant rhizosphere microbial communities. Illumina MiSeq sequencing technology was used to sequence the v3-V4 region of the 16SrDNA gene of 13 plant rhizosphere soil bacteria and the ITS1 region of the fungal ITSrDNA gene. Results showed that there were 355 families, 638 genera, and 719 species of rhizosphere soil bacteria as well as 29 families, 31 genera, and 31 species of rhizosphere soil fungi in the tropical cloud forests. The fine root traits, such as root phosphorus content, the specific root length and specific root area, were significantly negatively correlated with the Faith-pd indices of the bacterial community but were not correlated with the diversity of fungi communities. The soil pH was significantly and positively correlated with the Chao1 index, OTUs, Faith-pd and Simpson indices of the bacteria and fungi communities. The soil available phosphorus content was significantly and negatively correlated with the bacteria Simpson and the fungus Faith-pd indices. ABT analysis showed that soil pH and soil available phosphorus were the most important environmental conditions contributing to the rhizosphere bacterial and fungi communities, respectively. Our findings demonstrate that the soil environments had more influence on rhizosphere soil microbial diversity than the fine root functional traits.

Diversity and structure of the rhizosphere microbial communities of wild and cultivated ginseng

Background The resources of wild ginseng have been reducing sharply, and it is mainly dependent on artificial cultivation in China, Korea and Japan. Based on cultivation modes, cultivated ginseng include understory wild ginseng (the seeds or seedlings of cultivated ginseng were planted under the theropencedrymion without human intervention) and farmland cultivated ginseng (grown in farmland with human intervention). Cultivated ginseng, can only be planted on the same plot of land consecutively for several years owing to soilborne diseases, which is mainly because of the variation in the soil microbial community. In contrast, wild ginseng can grow for hundreds of years. However, the knowledge of rhizosphere microbe communities of the wild ginseng is limited.ResultIn the present study, the microbial communities in rhizosphere soils of the three types of ginseng were analyzed by high-throughput sequencing of 16 S rRNA for bacteria and internal transcribed spacer (ITS) region for fungi. In total, 4,381 bacterial operational taxonomic units (OTUs) and 2,679 fungal OTUs were identified in rhizosphere soils of the three types of ginseng. Among them, the shared bacterial OTUs was more than fungal OTUs by the three types of ginseng, revealing fungal communities were to be more affected than bacterial communities. In addition, the composition of rhizosphere microbial communities and bacterial diversity were similar between understory wild ginseng and wild ginseng. However, higher bacterial diversity and lower fungal diversity were found in rhizosphere soils of wild ginseng compared with farmland cultivated ginseng. Furthermore, the relative abundance of Chloroflexi, Fusarium and Alternaria were higher in farmland cultivated ginseng compared to wild ginseng and understory wild ginseng.ConclusionsOur results showed that composition and diversity of rhizosphere microbial communities were significantly different in three types of ginseng. This study extended the knowledge pedigree of the microbial diversity populating rhizospheres, and provided insights into resolving the limiting bottleneck on the sustainable development of P. ginseng crops, and even the other crops of Panax.

Impact of cropping systems on the functional diversity of rhizosphere microbial communities associated with maize plant: a shotgun approach.

Understanding the functions carried out by rhizosphere microbiomes will further explore their importance in biotechnological improvement and agricultural sustainability. This study presents one of the foremost attempts to understand the functional diversity of the rhizosphere microbiome in mono-cropping and crop rotation farming sites using shotgun metagenomic techniques. We hypothesized that the functional diversity would vary in the cropping sites and more abundant in the rotational cropping site. Hence, we carried out complete DNA extraction from the bulk and rhizospheric soils associated with maize plant cultivated on the mono-cropping farm (LT and LTc) and the crop rotation farm (VD and VDc), respectively, and sequenced employing shotgun approach. Using the SEED subsystem, our result revealed that a total of 24 functional categories dominated the rotational cropping site, while four functional categories dominated the mono-cropping sites. Alpha diversity assessment showed that no significant difference (p > 0.05) was observed across the cropping sites, while beta diversity assessment revealed a significant difference. Going by the high abundance of functional groups observed in the samples from the crop rotational site, it is evident that cropping systems influenced the functions of soil microbiomes. Worthy of note is the high abundance of unknown functions associated with these maize rhizosphere microbiomes. This is an indication that there are still some under-investigated functional genes associated with the maize rhizosphere microbiome. It is, therefore, imperative that further studies explore these functional genes for their agricultural and biotechnological potentials.

Comparison and interpretation of characteristics of Rhizosphere microbiomes of three blueberry varieties

BackgroundStudies on the rhizosphere microbiome of various plants proved that rhizosphere microbiota carries out various vital functions and can regulate the growth and improve the yield of plants. However, the rhizosphere microbiome of commercial blueberry was only reported by a few studies and remains elusive. Comparison and interpretation of the characteristics of the rhizosphere microbiome of blueberry are critical important to maintain its health.ResultsIn this study, a total of 20 rhizosphere soil samples, including 15 rhizosphere soil samples from three different blueberry varieties and five bulk soil samples, were sequenced with a high-throughput sequencing strategy. Based on these sequencing datasets, we profiled the taxonomical, functional, and phenotypic compositions of rhizosphere microbial communities for three different blueberry varieties and compared our results with a previous study focused on the rhizosphere microbiome of blueberry varieties. Our results demonstrated significant differences in alpha diversity and beta diversity of rhizosphere microbial communities of different blueberry varieties and bulk soil. The distribution patterns of taxonomical, functional, and phenotypic compositions of rhizosphere microbiome differ across the blueberry varieties. The rhizosphere microbial communities of three different blueberry varieties could be distinctly separated, and 28 discriminative biomarkers were selected to distinguish these three blueberry varieties. Core rhizosphere microbiota for blueberry was identified, and it contained 201 OTUs, which were mainly affiliated with Proteobacteria, Actinobacteria, and Acidobacteria. Moreover, the interactions between OTUs of blueberry rhizosphere microbial communities were explored by a co-occurrence network of OTUs from an ecological perspective.ConclusionsThis pilot study explored the characteristics of blueberry’s rhizosphere microbial community, such as the beneficial microorganisms and core microbiome, and provided an integrative perspective on blueberry’s rhizosphere microbiome, which beneficial to blueberry health and production.

Effects of inorganic and organic treatments on the microbial community of maize rhizosphere by a shotgun metagenomics approach

PurposeThe main drivers of biogeochemical cycling of nutrients, plant growth promotion, and disease suppression are microbes. Organic manure increases soil quality and plant productivity; the same is true of inorganic fertilizer. In this study, we explored shotgun metagenomics study to investigate how maize (Zea mays everta) rhizosphere microbial community diversity is shaped following the application of both compost manure and inorganic fertilizer.MethodsWe used high throughput next-generation sequencing—metagenomics studies to examine the rhizosphere microbial community of maize plants grown in an organic compost manure (8 tons/ha and 4 tons/ha) and inorganic (120 kg/ha NPK and 60 kg/ha NPK chemical) fertilized soils. An unfertilized soil was used as a control.ResultsThe taxonomic analysis of the soil revealed that regardless of the fertilization regimes, Proteobacteria and Bacteroidetes are distributed across all the samples, but in varying populations. Higher quantities of organic manure (8 tons/ha) and lower (60 kg/ha) nitrogen fertilizer, as well as the untreated control, supports the selection and enrichment of Proteobacteria and Actinobacteria, while lower quantities of organic compost (4 tons/ha) manure boost the population of Bacteroidetes. Firmicutes, on the other hand, were most abundant in low organic manure (4 tons/ha) and higher inorganic (120 kg/ha) fertilized soil. Fungi were selected and enriched by higher (8 tons/ha) and lower (4 tons/ha) compost manure, while archaea were mostly supported by higher doses of inorganic fertilizers (120 kg/ha) and high compost manure (8 tons/ha) treatments.ConclusionTherefore, comprehending the effects of compost and chemical fertilizers (NPK—20% nitrogen, 7% phosphorus, 3% potassium) on the community structure, dynamics, and abundance of rhizosphere microbiome will help in the manipulation of soil microbial community to increase microbial diversity in the agroecosystem.

Initial microbial status modulates mycorrhizal inoculation effect on rhizosphere microbial communities.

Arbuscular mycorrhizal fungi (AMF) play a central role in rhizosphere functioning as they interact with both plants and soil microbial communities. The conditions in which AMF modify plant physiology and microbial communities in the rhizosphere are still poorly understood. In the present study, four different plant species, (clover, alfalfa, ryegrass, tall fescue) were cultivated in either sterilized (γ ray) or non-sterilized soil and either inoculated with a commercial AMF (Glomus LPA Val 1.) or not. After 20weeks of cultivation, the mycorrhizal rate and shoot and root biomasses were measured. The abundance and composition of bacteria, archaea, and fungi were analyzed, respectively, by quantitative PCR (qPCR) and fingerprinting techniques. Whilst sterilization did not change the AMF capacity to modify plant biomass, significant changes in microbial communities were observed, depending on the taxon and the associated plant. AMF inoculation decreases both bacterial and archaeal abundance and diversity, with a greatest extent in sterilized samples. These results also show that AMF exert different selections on soil microbial communities according to the plant species they are associated with. This study suggests that the initial abundance and diversity of rhizosphere microbial communities should be considered when introducing AMF to cultures.

Effects of Bentonite on Chemical Forms and Bioavailability of Heavy Metals in Different Types of Farmland Soils

A pot experiment was conducted to evaluate the effects of bentonite on the physicochemical properties of soil; chemical forms of Cd, As, V, and Cr; pakchoi (Brassica chinensis L.) growth; metal uptake; and rhizosphere microbial community in three different types of farmland soils. The results showed that bentonite decreased the exchangeable Cd in the sequence of Yellow earths (Gy, 19.44%) > Yellow-cinnamon soils (Sy, 13.85%) > Fluvo-aquic soils (Bf, 5.03%), and the content of Cd in shoots of pakchoi declined in the sequence of Gy (34.81%) > Bf (23.91%) > Sy (11.11%), compared with the controls. Compared with the controls, the exchangeable As in Bf and Sy decreased by 4.53% and 25.16%, respectively, while the exchangeable As in Gy increased by 0.57%. The exchangeable Cr was increased in the sequence of Sy (31.30%) > Gy (2.91%) > Bf (0.58%). The residual As, V, and Cr increased (except for Cr in Sy), and their uptake was also reduced in different degrees. The addition of bentonite significantly promoted the growth of pakchoi in the three soil types, especially in Bf. pakchoi biomass, root surface area, and number of root tips increased by 147.55%, 80.71%, and 124.31%, respectively, in Bf, compared with the control. In addition, bentonite reduced the content of available nitrogen, phosphorus, and organic matter; increased the content of available potassium; and increased the diversity of rhizosphere microbial community in all three soils. Therefore, bentonite could be highly recommended as a safe stabilizer in these three types of soil.

Structural and metabolic diversity of rhizosphere microbial communities of Phragmites karka in a tropical coastal lagoon

The structural and metabolic diversity of rhizosphere microbial communities of Phragmites karka, a perennial reed, was examined through high-throughput sequencing of 16S rRNA genes, taxonomic-to-metabolic mapping, and the BIOLOG® community level physiological profiling. Rhizosphere sediments were collected from P. karka stands along the shoreline of Chilika Lagoon during the year 2014–2015. At the genus level, bacterial communities were largely composed of Thiobacillus, Methylotenera, Bacillus, Steroidobacter and Escherichia/Shigella whereas Methanomassiliicoccus was one of the most abundant genus in the archaeal communities. In general, rhizosphere communities of samples from the same locations were more similar in their composition than from other sites. Salinity played an important role in driving the community composition along with ‘rhizosphere effect’. Carbon substrate utilization profiles of rhizosphere communities were highly diverse and the highest utilization was recorded in wells containing tween 40 (polymer), D-mannitol (carbohydrates), L-asparagine (amino acids), 4-hydroxybenzoic acid (phenols), putrescine (amines), and D-galacturonic acid (carboxylic acids). Of these, L-asparagine and D-mannitol were preferentially utilized by all rhizosphere communities. Metabolic mapping suggested that rhizosphere microbial communities could play a critical role in maintaining the ecological health of coastal wetlands through cycling of carbon, nitrogen, and sulfur, and degradation of hydrocarbon and xenobiotic compounds. Overall, this study demonstrated a high variability in the community structure and carbon metabolic profiles of rhizosphere communities of P. karka and suggested that nutrient cycling related ecosystem services that are mediated by the rhizosphere microbial communities of reeds must be included in the management and conservation plan of wetlands.

黄萎病不同发生程度棉田中土壤微生物多样性

PDF HTML阅读 XML下载 导出引用 引用提醒 黄萎病不同发生程度棉田中土壤微生物多样性 DOI: 10.5846/stxb201702060218 作者: 作者单位: 中国农业大学植物保护学院，新疆农业科学院植物保护研究所,新疆农业科学院植物保护研究所,新疆农业科学院植物保护研究所,新疆农业科学院植物保护研究所,新疆农业大学农学院,中国农业大学植物保护学院 作者简介: 通讯作者: 中图分类号: 基金项目: 新疆自治区重点研发计划项目（2016B01001-6）；国家棉花产业技术体系岗位科学家项目（CARS-18）；公益性行业（农业）科研专项经费项目（201503112-6） Analysis of soil microbial diversity in cotton fields differing in occurrence of cotton Verticillium wilt in Xinjiang Author: Affiliation: College of Plant Protection,China Agricultural University,Institute of Plant Protection,Xinjiang Academy of Agricultural Sciences,Institute of Plant Protection,Xinjiang Academy of Agricultural Sciences,Institute of Plant Protection,Xinjiang Academy of Agricultural Sciences,College of Agronomy,Xinjiang Agricultural University,College of Plant Protection,China Agricultural University;Institute of Plant Protection,Xinjiang Academy of Agricultural Sciences;College of Agronomy,Xinjiang Agricultural University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:作物根际土壤微生物群落对土壤生态及作物健康至关重要。以棉花黄萎病不同发生程度棉田的土壤为研究对象，采用理化分析、微生物纯培养及高通量测序技术对土壤理化性质及微生物数量、细菌丰度多样性进行综合分析。结果表明：在纯培养条件下，大丽轮枝菌无菌发酵滤液对细菌生长有明显的抑制作用；棉田接种大丽轮枝菌对土壤中细菌、真菌、放线菌的数量及细菌菌群丰度多样性未产生明显影响，不同采样时间的土壤中细菌菌群结构差异更大。土壤中大丽轮枝菌微菌核数量与棉花黄萎病的发生程度呈显著正相关。土壤肥力对土壤中微生物数量起主导作用，而水稻-棉花轮作能够使棉田有效降盐、减病、改善土壤肥力。通过生物防治、作物轮作、深翻等调控措施增加土壤中有益菌群数量、改善土壤生态、降低棉田土壤中大丽轮枝菌菌源数量是减轻棉花黄萎病危害的基础。 Abstract:Soil microbial community composition of crop rhizosphere is very important in soil ecology and crop health. In this paper, the soil with different levels of cotton Verticillium wilt is the research object. Moreover, physical and chemical properties of soil, and rhizosphere microbial community diversity were analyzed with the technique of microbial pure culture, physical and chemical analysis and high-throughput sequencing. The results indicate that sterile fermentation liquor of Verticillium dahliae has obvious inhibitory effect on bacterial growth in pure culture conditions. After inoculation with V. dahliae, the quantity of bacteria, fungi, and actinomycetes in the cotton soil show little change compared to that in the control. High-throughput sequencing analysis indicates that bacterial genetic relationship in soil shows no significant change, and sampling time has a bigger impact on the bacterial population structure. Soil fertility plays a key role in determining the quantity of bacteria, fungi, and actinomycetes in continuous cotton cropping soil, in which Verticillium wilt occurrence is severe and significantly higher than that in the control field. Rice-cotton rotation cropping has a strong effect on reducing salt, plant diseases, and improving soil fertility. Microsclerotia content in soil has significant positive correlation with the incidence of cotton Verticillium wilt. Soil fertility, culture measures, and crop varieties mainly influence soil microorganism quantity; however, Verticillium wilt occurrence does not cause significant change in microbial quantity. Reducing the quantity of microsclerotia in soil is the fundamental method of controlling Verticillium wilt. 参考文献 相似文献 引证文献

大庆盐碱地九种植物根际土壤微生物群落结构和功能多样性

大庆盐碱地九种植物根际土壤微生物群落结构和功能多样性

Metabolic activity and genetic diversity of microbial communities inhabiting the rhizosphere of halophyton plants

A preliminary study was conducted to compare the community level physiological profile (CLPP) and genetic diversity of rhizosphere microbial communities of four plant species growing nearby Kiskunság soda ponds, namely Böddi-szék, Kelemen-szék and Zab-szék. CLPP was assessed by MicroResp method using 15 different substrates while Denaturing Gradient Gel Electrophoresis (DGGE) was used to analyse genetic diversity of bacterial communities. The soil physical and chemical properties were quite different at the three sampling sites. Multivariate statistics (PCA and UPGMA) revealed that Zab-szék samples could be separated according to their genetic profile from the two others which might be attributed to the geographical location and perhaps the differences in soil physical properties. Böddi-szék samples could be separated from the two others considering the metabolic activity which could be explained by their high salt and low humus contents. The number of bands in DGGE gels was related to the metabolic activity, and positively correlated with soil humus content, but negatively with soil salt content. The main finding was that geographical location, soil physical and chemical properties and the type of vegetation were all important factors influencing the metabolic activity and genetic diversity of rhizosphere microbial communities.