Different genotypes regulate the microbial community structure in the soybean rhizosphere

The soybean rhizosphere has a specific microbial community,but the differences in microbial community structure between different soybean genotypes have not been explained.The present study analyzed the structure of the rhizosphere microbial community in three soybean genotypes.Differences in rhizosphere microbial communities between different soybean genotypes were verified using diversity testing and community composition,and each genotype had a specific rhizosphere microbial community composition.Co-occurrence network analysis found that different genotype plant hosts had different rhizosphere microbial networks.The relationship between rhizobia and rhizosphere microorganisms in the network also exhibited significant differences between different genotype plant hosts.The ecological function prediction found that different genotypes of soybean recruited the specific rhizosphere microbial community.These results demonstrated that soybean genotype regulated rhizosphere microbial community structure differences.The study provides a reference and theoretical support for developing soybean microbial inoculum in the future.

Heavy metal (Pb,Zn) uptake and chemical changes in rhizosphere soils of four wetland plants with different radial oxygen loss

Lead and Zn uptake and chemical changes in rhizosphere soils of four emergent-rooted wetland plants;Aneilema bracteatum,Cyperus alternifolius,Ludwigia hyssopifolia and Veronica serpyllifolia were investigated by two experiments：（1） rhizobag filled with ＂clean＂ or metal-contaminated soil for analysis of Pb and Zn in plants and rhizosphere soils;and （2） applied deoxygenated solution for analyzing their rates of radial oxygen loss （ROL）.The results showed that the wetland plants with different ROL rates had significant effects on the mobility and chemical forms of Pb and Zn in rhizosphere under flooded conditions.These effects were varied with different metal elements and metal concentrations in the soils.Lead mobility in rhizosphere of the four plants both in the ＂clean＂ and contaminated soils was decreased,while Zn mobility was increased in the rhizosphere of the ＂clean＂ soil,but decreased in the contaminated soil.Among the four plants,V.serpyllifolia,with the highest ROL,formed the highest degree of Fe plaque on the root surface,immobilized more Zn in Fe plaque,and has the highest effects on the changes of Zn form （EXC-Zn） in rhizosphere under both ＂clean＂ and contaminated soil conditions.These results suggested that ROL of wetland plants could play an important role in Fe plaque formation and mobility and chemical changes of metals in rhizosphere soil under flood conditions.

Characterization of Bacterial Community Structure and Diversity in Rhizosphere Soils of Three Plants in Rapidly Changing Salt Marshes Using 16S rDNA

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.

Seasonal comparison of bacterial communities in rhizosphere of alpine cushion plants in the Himalayan Hengduan Mountains

Positive associations between alpine cushion plants and other species have been extensively studied.However,almost all studies have focused on the associations between macrofauna.Studies that have investigated positive associations between alpine cushion plants and rhizospheric microbes have been limited to the vegetation growing season.Here,we asked whether the positive effects that alpine cushion plants confer on rhizospheric microbe communities vary with seasons.We assessed seasonal variations in the bacterial diversity and composition in rhizosphere of two alpine cushion plants and surrounding bare ground by employing a high throughput sequencing method targeting the V3 region of bacterial 16 S rRNA genes.Soil properties of the rhizosphere and the bare ground were also examined.We found that cushion rhizospheres harbored significantly more C,N,S,ammonia nitrogen,and soil moisture than the bare ground.Soil properties in cushion rhizospheres were not notably different,except for soil pH.Bacterial diversities within the same microhabitats did not vary significantly with seasons.We concluded that alpine cushion plants had positive effects on the rhizospheric bacterial communities,even though the strength of the effect varied in different cushion species.Cushion species and the soil sulfur content were probably the major factors driving the spatial distribution and structure of soil bacterial communities in the alpine communities dominated by cushion plants.

Application of PCR primer sets for detection of <i>Pseudomonas</i>sp. functional genes in the plant rhizosphere

Plant growth promoting pseudomonads play an important role in disease suppression and there is considerable interest in development of bio-marker genes that can be used to monitor these bacteria in agricultural soils. Here, we report the application ofa PCR primer sets targeting genes encoding the main antibiotic groups. Distribution of the genes was variably distributed across type strains of 28 species with no phylogenetic groupingfor the detected antibioticsgenes, phlD for 2,4-diacetylphloroglucinol (2,4-DAPG) and phzCD for phenazine-1-carboxylic acid or hcnBC for hydrogen cyanide production. Analysis of field soils showed that primer sets for phlD and phzCD detected these genes in a fallowed neutral pH soil following wheat production, but that the copy numbers were below the detection limits in bulk soils having an acidic pH. In contrast, PCR products for the phzCD, pltc and hcnBc genes were detectable in mature root zones following plantingwith wheat. The ability to rapidly characterize populations of antibiotics producers using specific primer sets will improve our ability to assess the impacts of management practices on the functional traits of Pseudomonas spp. populations in agricultural soils.

Genotypic Difference of Plants in K-Enrichment Capability and the Distribution of K in Plant Rhizosphere

Plant genotypic difference of pot assiu m-enr ich ment capab ility and p ot assi um (K ) d ist rib ut ion at root-soil ioterface of different plant genotypes were studied by using seven plant species and eight varieties oftobacco (Nicotiana tabacum L.). The results indicated that K enrichment capability was: Ethiopian guizotia(Guizotia abyssinica Cass.)>feather cockscomb (Celosia arpentea L.)>alligator alternanthera (Alternantheraphiloxeroides (Mart.) Griseb.)> tobacco>sesbania (Sesbania cannabina (Retz.) Pers.)>wheat (Thticumaestivum L.)>broadbean (Vicia faba L.). Ethiopian guizotia showed very high K-enrichment capability atdifferent soil K levels, and the K content in its dry matter was over 110 mg kg-1 when soil K was fullysupplied, and about 60 mg kg-1 when no K fertilizer was applied. For alligator alternanthera, the capabilityto accumulate K was closely related with its growth medium. When it was grown on soils, both the K contentand K uptake rate of the plant were similar to those of tobacco. Evident K dep1etion was observed in therhizosphere of all plant species, and the depletion rate was related to the capability of K enrichment of plant.

Nitrification intensity and ammonia-oxidizing bacteria and archaea in different wetland plant rhizosphere soils

In order to explore the nitrogen removal process in constructed wetlands(CW s),the moisture,ammonia nitrogen(NH4+-N),nitrate nitrogen(NO3"-N)and nitrification intensity in three wetland plant rhizosphere soils(Acorns calamus,Typha orientalis,Iris pseudacorus)were investigated at a relatively normal temperature range of15to25The relative abundance of ammonia-oxidizing bacteria(AOB)and ammonia-oxidizing archaea(AOA)were also achieved using fluorescence in situ hybridization(FISH).It is found that T.orientalis achieves the highest nitrification intensity of2.03m g(h?kg)while the second is I.pseudacorrs(1.74m g/(h?kg)),and followed by A.calamus(1.65m g/(h?kg))throughout the experiment.FISH reveals that the abundance of bacteria(1010g_1wet soil)is higher than that of archaea(109g_1wet soil),and AOBare the dominant bacteria in the ammonia oxidation process.The abundance of AOB in te rhizosphere soils from high to low T.orientalis(1.88x1010g"1),I pseudacorus(1.23x1010g1),A.calamus(5.07x109g"1)while the abundance of AOA from high to low ae I.pseudacorus(4.00x109g1),A.calamus(3.52x109g"1),T.orientalis(3.48x109g"1).The study provides valuable evidence of plant selection for nitrogen removal in CWs.

Response of nitrogen fractions in the rhizosphere and bulk soil to organic mulching in an urban forest plantation

Nitrogen is an essential component in forest ecosystem nutrient cycling.Nitrogen fractions,such as dissolved nitrogen,ammonium,nitrate,and microbial biomass nitrogen,are sensitive indicators of soil nitrogen pools which affect soil fertility and nutrient cycling.However,the responses of nitrogen fractions in forest soils to organic mulching are less well understood.The rhizosphere is an important micro-region that must be considered to better understand element cycling between plants and the soil.A field investigation was carried out on the effect of mulching soil in a 15-year-old Ligustrum lucidum urban plantation.Changes in total nitrogen and nitrogen fractions in rhizosphere and bulk soil in the topsoil(upper 20 cm)and in the subsoil(20-40 cm)were evaluated following different levels of mulching,in addition to nitrogen contents in fine roots,leaves,and organic mulch.The relationships between nitrogen fractions and other measured variables were analysed.Organic mulching had no significant effect on most nitrogen fractions except for the rhizosphere microbial biomass nitrogen(MBN),and the thinnest(5 cm)mulching layer showed greater effects than other treatments.Rhizosphere MBN was more sensitive to mulching compared to bulk soil,and was more affected by soil environmental changes.Season and soil depth had more pronounced effects on nitrogen fractions than mulching.Total nitrogen and dissolved nitrogen were correlated to soil phosphorus,whereas other nitrogen fractions were strongly affected by soil physical properties(temperature,water content,bulk density).Mulching also decreased leaf nitrogen content,which was more related to soil nitrogen fractions(except for MBN)than nitrogen contents in either fine roots or organic mulch.Frequent applications of small quantities of organic mulch contribute to nitrogen transformation and utilization in urban forests.

Different responses of soil fauna gut and plant rhizosphere microbiomes to manure applications

Microbial attributes were compared between soil fauna gut and plant rhizosphere.•Manure applications decreased or increased gut or rhizosphere bacterial diversity.•Stochastic or deterministic processes drove gut or rhizosphere bacterial assembly.•Manure applications increased bacterial network complexity of gut and rhizosphere.Diverse microbes inhabit animals and plants,helping their hosts perform multiple functions in agricultural ecosystems.However,the responses of soil fauna gut and plant rhizosphere microbiomes to livestock manure applications are still not well understood.Here we fed Protaetia brevitarsis larvae(PBL)with chicken manure and collected their frass.The frass and manure were applied as fertilizers to lettuce pots.We then compared the changes of microbial diversity,community assembly,and potential functions between the gut group(i.e.,all PBL gut and frass samples)and the rhizosphere group(i.e.,all rhizosphere soil samples).We revealed that manure applications(i.e.,feeding or fertilization)decreased bacterial diversity in the gut group but increased that in the rhizosphere group.Particularly,the proportions of Bacilli in the gut group and Gammaproteobacteria in the rhizosphere group were increased(up to a maximum of 33.8%and 20.4%,respectively)after manure applications.Stochastic and deterministic processes dominated community assembly in the gut and rhizosphere microbiomes,respectively.Manure applications increased the microbial co-occurrence network complexity of both the gut and rhizosphere groups.Moreover,the proportions of functional taxa associated with human/animal pathogens in the gut group and carbon/nitrogen cycling in the rhizosphere group were enhanced(up to 2.6-fold and 24.6-fold,respectively).Our findings illustrate the different responses of microbial diversity,community assembly,and potential functions in soil fauna gut and plant rhizosphere to manure applications.The results could enhance our knowledge on the reasonable utilization of animal and plant microbiomes in agricultural management.

Root Exudates, Rhizosphere Zn Fractions, and Zn Accumulation of Ryegrass at Different Soil Zn Levels

A glasshouse experiment was conducted using a root-bag technique to study the root exudates, rhizosphere Zn fractions, and Zn concentrations and accumulations of two ryegrass cultivars （Lolium perenne L. cvs. Airs and Tede） at different soil Zn levels （0, 2, 4, 8, and 16 mmol kg^-1 soil）. Results indicated that plant growth of the two cultivars was not advérsely affected at soil Zn level ≤ 8 mmol kg^-1. Plants accumulated more Zn as soil Zn levels increased, and Zn concentrations of shoots were about 540 μg g^-1 in Aris and 583.9 μg g^-1 in Tede in response to 16 mmol Zn kg^-1 soil. Zn ratios of shoots to roots across the soil Zn levels were higher in Tede than in Airs, corresponding with higher rhizosphere available Zn fractions （exchangeable, bound to manganese oxides, and bound to organic matter） in Airs than in Tede. Low-molecular-weight （LMW） organic acids （oxalic, tartaric, malic, and succinic acids） and amino acids （proline, threonine, glutamic acid, and aspartic acid, etc.） were detected in root exudates, and the concentrations of LMW organic acids and amino acids increased with addition of 4 mmol Zn kg^-1 soil compared with zero Zn addition. Higher rhizosphere concentrations of oxalic acid, glutamic acid, alanine, phenylalanine, leucine, and proline in Tede than in Airs likely resulted in increased Zn uptake from the soil by Tede than by Airs. The results suggested that genotypic differences in Zn accumulations were mainly because of different root exudates and rhizosphere Zn fractions.

Assessing bacterial communities in the rhizosphere of 8-year-old genetically modified poplar(Populus spp.)

Microbe communities in rhizosphere ecosystems are important for plant health but there is limited knowledge of them in the rhizospheres of genetically modified（GM） plants, especial for tree species. We used the amplitude sequencing method to analyze the V4 regions of the 16 S r RNA gene to identify changes in bacterial diversity and community structure in two GM lines（D520 and D521）, one non-genetically modified（nonGM） line and in uncultivated soil. After chimera filtering,468.133 sequences in the domain Bacteria remained. There were ten dominant taxonomic groups（with [1 % of all sequences） across the samples. 241 of 551 genera（representing a ratio of 97.33 %） were common to all samples.A Venn diagram showed that 1.926 operational taxonomic units（OTUs） were shared by all samples. We found a specific change, a reduction in Chloroflexi, in the microorganisms in the rhizosphere soil planted with poplars. Taken together, the results showed few statistical differences in the bacterial diversity and community structure between the GM line and non-GM line, this suggests that there was no or very limited impact of this genetic modification on the bacterial communities in the rhizosphere.

How do nitrogen-limited alpine coniferous forests acquire nitrogen?A rhizosphere perspective

Background:Alpine coniferous forest ecosystems dominated by ectomycorrhizal(ECM)tree species are generally characterized by low soil nitrogen(N)availability but stabilized plant productivity.Thus,elucidating potential mechanisms by which plants maintain efficient N acquisition is crucial for formulating optimized management practices in these ecosystems.Methods:We summarize empirical studies conducted at a long-term field monitoring station in the alpine coniferous forests on the eastern Tibetan Plateau,China.We propose a root-soil interaction-based framework encompassing key components including soil N supply,microbial N transformation,and root N uptake in the rhizosphere.Results:We highlight that,(i)a considerable size of soil dissolved organic N pool mitigates plant dependence on inorganic N supply;(ii)ectomycorrhizal roots regulate soil N transformations through both rhizosphere and hyphosphere effects,providing a driving force for scavenging soil N;(iii)a complementary pattern of plant uptake of different soil N forms via root-and mycorrhizal mycelium-pathways enables efficient N acquisitions in response to changing soil N availability.Conclusions:Multiple rhizosphere processes abovementioned collaboratively contribute to efficient plant N acquisition in alpine coniferous forests.Finally,we identify several research outlooks and directions to improve the understanding and prediction of ecosystem functions in alpine coniferous forests under on-going global changes.

间作黄芪对当归根际土壤微生物的影响

目的:探讨根际土壤微生物对中药材种植模式的响应方式。方法:以间作黄芪及单作下当归根际土壤为研究对象,基于高通量测序技术,分析土壤微生物在不同季节及种植模式下群落组成及功能的差异。结果:间作下Chao1指数、ACE指数高于单作,变形菌门、放线菌门、酸杆菌门、绿弯菌门和芽单胞菌门为间作下的优势菌门,芽单胞菌门的相对丰度在间作下高于单作。11月间作下γ变形菌纲、7月间作下全噬菌纲的丰度显著高于单作。KEGG功能预测表明,在不同时间及间作下根际土壤细菌与细胞过程、环境信息处理、遗传信息处理、代谢功能下属的23类二级功能基因的相对丰度存在显著差异;参与氮循环的功能基因K00371(narH/narY/nxrB)、(K00374 narI/narV)等OTU数在间作下显著高于单作;不同门、纲在间作下的共生网络比单作下连接紧密且更复杂。结论:当归间作黄芪影响土壤细菌群落组成,增加其丰富度及功能的丰富性,影响土壤氮循环能力,促进土壤微生物间的交互作用。

生物刺激素对烤烟根际微生态及烟叶品质的影响

【目的】探究生物刺激素在烤烟栽培上的应用效果,为植烟土壤改良及烟叶品质改善提供新的思路。【方法】采用大田试验,以常规施肥为对照(CK),在CK基础上设施用海藻酸(BS1)、古生物源生物刺激素(BS2)和矿源黄腐酸(BS3)3个生物刺激素处理,于烤烟盛花期取烟株根围土壤测定土壤理化性质(pH、阳离子交换量及有机质、碱解氮、速效磷、速效钾含量)、酶(蔗糖酶、硝酸还原酶、过氧化氢酶、脲酶)活性及微生物群落多样性;于烤烟成熟时调查农艺性状(株高、茎围、有效叶片数、最大腰叶长、最大腰叶宽、顶叶长、顶叶宽、叶面积),并对上部叶(倒数第5~6片烟叶)进行标识,调制后进行化学成分(总糖、还原糖、烟碱、总氮、钾、氯、淀粉含量,糖碱比、氮碱比、钾氯比)测算,分析3种生物刺激素对植烟土壤微生态环境及烟叶品质的影响。【结果】与CK相比,BS1和BS3处理不同程度提高了植烟土壤氮、磷、钾速效养分含量及阳离子交换量,极显著提高了土壤蔗糖酶和脲酶活性;明显提高土壤优势菌门奇古菌门(Thaumarchaeota)和根肿黑粉菌门(Entorrhizomycota)的相对丰度,以及优势菌属根肿黑粉菌属(Entorrhiza)的相对丰度,而降低子囊菌门(Ascomycota)和镰刀菌属(Fusarium)的相对丰度;BS3处理土壤细菌、真菌群落的丰富度和多样性及其功能代谢途径丰度均高于CK、BS1和BS2处理;施用生物刺激素可促进烤烟生长发育和烟叶开片,其中BS3处理有利于提高烟叶化学成分适宜性和协调性。【结论】矿源黄腐酸处理改良土壤、促进烤烟生长及提升烟叶品质的综合效应较优,是适合烤烟施用的生物刺激素。

番茄疫霉根腐病菌拮抗细菌HP8-1的鉴定及生物防治潜力

【目的】探究HP8-1在番茄上的生物防治潜力,为番茄疫霉根腐病的生物防治提供优良生物防治资源。【方法】通过形态学观察、生理生化特性检测并结合16S rRNA序列分析鉴定HP8-1菌株,探讨其对植物病原菌的抑菌效果和生物学功能及在番茄根际的定殖能力,并通过盆栽试验测定其对番茄疫霉根腐病的防治效果和对番茄生长的影响。【结果】HP8-1为多粘类芽孢杆菌(Paenibacillus polymyxa),对多种植物病原菌具有抑菌效果,具有解磷、分解蛋白、分解纤维素、产嗜铁素和产吲哚乙酸等生物学功能;HP8-1在番茄根系和根际土壤具有稳定的定殖能力,尤其是在接种疫霉菌的条件下其定殖量趋于增加并显著高于未接种疫霉菌的条件;HP8-1处理对番茄疫霉根腐病具有明显的防治效果,防治效果达到57.41%;同时,HP8-1处理显著促进番茄植株生长、提高叶绿素含量和根系活力。【结论】HP8-1菌株稳定定殖在番茄根系和根际土壤,防治番茄疫霉根腐病,促进番茄生长,是对番茄疫霉根腐病具有生物防治潜力的资源。

垄作栽培提升黄花菜产量及改善根际土壤环境

[目的]本研究旨在提高黄花菜的产量,探索适宜大同地区黄花菜的有效栽培模式。[方法]于2022-2023年,以‘大同黄花’为试验材料,采用垄作、平作和沟栽3种栽培方式,通过测定分析黄花菜根际土壤理化属性、根系活力与生物量等指标,探究栽培方式对黄花菜产量的影响。[结果](1)垄作能显著降低0~20 cm土层土壤容重和土壤含水量,提高0~20 cm土层土壤孔隙度。垄作下0~10、10~20 cm土层土壤容重较平作分别降低4.88%和3.37%,土壤含水量分别显著降低17.03%和19.04%,土壤孔隙度分别提高8.28%和7.33%,而沟栽下0~10 cm土层土壤含水量较平作显著提高11.46%;(2)垄作提高0~20 cm土层土壤温度,尤其是表层0~5 cm温度变化幅度最大。(3)垄作提高0~30 cm土层土壤蔗糖酶和脲酶活性,其中0~10 cm土层酶活性最高。(4)在黄花菜展叶期、初花期和盛花期,垄作下的土壤碱解氮含量分别显著提高81.12%、111.42%、40.64%。(5)垄作提高根系活力,在黄花菜抽薹期较平作显著提高21.36%,随着生育进程的推进,根系干物质逐渐增加,在盛花期垄作较平作提高27.63%。(6)在产量方面,垄作较平作显著提高28.89%。[结论]垄作可提高土壤温度、孔隙度、土壤酶活性及土壤养分含量,为黄花菜创造良好的生态环境,利于根系生长,实现黄花菜高产,因此垄作是适合大同地区黄花菜的高效栽培模式。

Rhizosphere microbial markers (micro-markers): A new physical examination indicator for traditional Chinese medicines

Rhizosphere microorganisms,as one of the most important components of the soil microbiota and plant holobiont,play a key role in the medicinal plant-soil ecosystem,which are closely related to the growth,adaptability,nutrient absorption,stress tolerance and pathogen resistance of host plants.In recent years,with the wide application of molecular biology and omics technologies,the outcomes of rhizosphere microorganisms on the health,biomass production and secondary metabolite biosynthesis of medicinal plants have received extensive attention.However,whether or to what extent rhizosphere microorganisms can contribute to the construction of the quality evaluation system of Chinese medicinal materials is still elusive.Based on the significant role of rhizosphere microbes in the survival and quality formation of medicinal plants,this paper proposed a new concept of rhizosphere microbial markers(micro-markers),expounded the relevant research methods and ideas of applying the new concept,highlighted the importance of micro-markers in the quality evaluation and control system of traditional Chinese medicines(TCMs),and introduced the potential value in soil environmental assessment,plant pest control and quality assessment of TCMs.It provides reference for developing ecological planting of TCMs and ensuring the production of high quality TCMs by regulating rhizosphere microbial communities.

AMF和PGPR单独或“跨界”互作促进植物耐盐性的研究进展

盐碱地改良和利用对拓展我国后备耕地资源及保障国家粮食安全具有重要意义。根际微生物作为植物的“第二基因组”,在提高作物抗盐碱胁迫能力,促进作物“以种适地”方面具有巨大潜力。其中,丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)和植物根际促生细菌(plant growth promoting rhizobacteria,PGPR)均为重要的根际有益微生物,能显著提高植物耐盐性。本文分别总结了AMF和PGPR提高植物抗盐能力的相关研究进展,并进一步梳理了两者协同提高植物耐盐的机制,包括提高养分效率、调节激素内稳态、提高植物诱导抗性以及调控转录因子表达等,最后提出了基于两者跨界组合的改良方向。旨在充分理解盐胁迫条件下微生物耐盐促生的作用机制,为充分挖掘微生物资源潜力和发展生物技术治理盐碱地提供重要的科学支撑。

德兴矿区原生植物根际土壤真菌群落结构和多样性分析

为了解德兴废石堆场原生植物根际土壤真菌群落组成、分析群落结构与土壤理化性质之间的关系,本研究采用高通量测序技术分析矿区的金星蕨(Parathelypteris glanduligera)、紫金牛(Ardisia japonica)、太平莓(Rubus pacificus)和芒草(Miscanthus sinensis)根际真菌群落多样性。结果表明,4种原生植物根际土壤理化性质差异显著。4种植物根际土壤的优势真菌属于担子菌门和子囊菌门。主成分分析显示,4种原生植物根际土壤真菌群落结构存在差异,造成差异的指示属主要有金星蕨的红菇属,紫金牛的古根菌属和毛舌菌属,芒草的棉革菌属和色孢菌属。芒草的根际真菌群落丰富度和多样性最高。相关性分析表明,铅Pb和速效磷是影响根际真菌群落变化的主要环境因子。共生营养型真菌是金星蕨和太平莓根际土壤中的优势功能菌群。研究结果有助于了解德兴铜矿原生植物根际真菌生态功能,为废石堆场生态重建和植被恢复及筛选修复菌群提供了理论依据。

植物克隆整合生态效应及潜在应用

克隆植物因特殊的克隆整合和空间拓展特性,在异质生境下展示出较高的生态适应性及适合度,这是其广泛存在于各类生态系统的一个重要原因。目前对克隆整合在个体或种群水平的生态学效应已有较深认识,而对群落及生态系统的影响及作用机制则明显关注不足。前期研究表明,克隆整合对土壤理化性质、根际微生物及个体竞争力均有显著影响,从而有利于克隆植物的成功入侵、生境修复及植被重建等。对群落及生态系统水平的克隆整合生态学效应的研究进行归纳和总结,分析了克隆整合对植物群落结构和生产力、根际微生物和土壤动物、生态系统碳固持、养分循环等的影响;阐释了克隆整合及空间拓展特性对退化生态系统的修复及作用机制,并指出今后克隆整合的研究应同时考虑微观(根际过程)和宏观(群落及生态系统)层次的效应以及短期与长期的效应。可将克隆整合与植物-土壤反馈等其他生态过程相联系,综合探究克隆整合的生态学意义。