Plant species richness,identity and productivity differentially influence key groups of microbes in grassland soils of contrasting fertility

The abundance of microbes in soil is thought to be strongly influenced by plant productivity rather than by plant species richness per se. However, whether this holds true for different microbial groups and under different soil conditions is unresolved. We tested how plant species richness, identity and biomass influence the abundances of arbuscular mycorrhizal fungi (AMF), saprophytic bacteria and fungi, and actinomycetes, in model plant communities in soil of low and high fertility using phospholipid fatty acid analysis. Abundances of saprophytic fungi and bacteria were driven by larger plant biomass in high diversity treatments. In contrast, increased AMF abundance with larger plant species richness was not explained by plant biomass, but responded to plant species identity and was stimulated by Anthoxantum odoratum. Our results indicate that the abundance of saprophytic soil microbes is influenced more by resource quantity, as driven by plant production, while AMF respond more strongly to resource composition, driven by variation in plant species richness and identity. This suggests that AMF abundance in soil is more sensitive to changes in plant species diversity per se and plant species composition than are abundances of saprophytic microbes.     

Diversity and community structure of ectomycorrhizal fungi in a wooded meadow

Wooded meadows are seminatural plant communities that support high diversity of various taxa. Due to changes in land use, wooded meadows have severely declined during the last century. The dominant trees in wooded meadows acquire mineral nutrients via ectomycorrhizal fungi. Using anatomotyping and sequencing of root tips, interpolation and extrapolation methods, we studied the diversity and community structure of ectomycorrhizal fungi in two soil horizons of both managed and forested parts of a wooded meadow in Estonia. Species of Thelephoraceae, Sebacinaceae and the genus Inocybe dominated the whole ectomycorrhizal fungal community of 172 observed species. Forested and managed parts of the wooded meadow harboured different communities of ectomycorrhizal fungi, whereas soil horizon had a negligible effect on the fungal community composition. Diverse soil conditions and host trees likely support the high richness of ectomycorrhizal fungi in the wooded meadow ecosystem. Direct sequencing integrated with interpolation and extrapolation methods are promising to identify the fungi at the species level and to compare species richness between communities of ectomycorrhizal fungi.     

Fungal community composition in neotropical rain forests: the influence of tree diversity and precipitation

Plant diversity is considered one factor structuring soil fungal communities because the diversity of compounds in leaf litter might determine the extent of resource heterogeneity for decomposer communities. Lowland tropical rain forests have the highest plant diversity per area of any biome. Since fungi are responsible for much of the decomposition occurring in forest soils, understanding the factors that structure fungi in tropical forests may provide valuable insight for predicting changes in global carbon and nitrogen fluxes. To test the role of plant diversity in shaping fungal community structure and function, soil (0-20?cm) and leaf litter (O horizons) were collected from six established 1-ha forest census plots across a natural plant diversity gradient on the Isthmus of Panama. We used 454 pyrosequencing and phospholipid fatty acid analysis to evaluate correlations between microbial community composition, precipitation, soil nutrients, and plant richness. In soil, the number of fungal taxa increased significantly with increasing mean annual precipitation, but not with plant richness. There were no correlations between fungal communities in leaf litter and plant diversity or precipitation, and fungal communities were found to be compositionally distinct between soil and leaf litter. To directly test for effects of plant species richness on fungal diversity and function, we experimentally re-created litter diversity gradients in litter bags with 1, 25, and 50 species of litter. After 6?months, we found a significant effect of litter diversity on decomposition rate between one and 25 species of leaf litter. However, fungal richness did not track plant species richness. Although studies in a broader range of sites is required, these results suggest that precipitation may be a more important factor than plant diversity or soil nutrient status in structuring tropical forest soil fungal communities.     

Strong coupling of plant and fungal community structure across western Amazonian rainforests

The Amazon basin harbors a diverse ecological community that has a critical role in the maintenance of the biosphere. Although plant and animal communities have received much attention, basic information is lacking for fungal or prokaryotic communities. This is despite the fact that recent ecological studies have suggested a prominent role for interactions with soil fungi in structuring the diversity and abundance of tropical rainforest trees. In this study, we characterize soil fungal communities across three major tropical forest types in the western Amazon basin (terra firme, seasonally flooded and white sand) using 454 pyrosequencing. Using these data, we examine the relationship between fungal diversity and tree species richness, and between fungal community composition and tree species composition, soil environment and spatial proximity. We find that the fungal community in these ecosystems is diverse, with high degrees of spatial variability related to forest type. We also find strong correlations between α- and β-diversity of soil fungi and trees. Both fungal and plant community β-diversity were also correlated with differences in environmental conditions. The correlation between plant and fungal richness was stronger in fungal lineages known for biotrophic strategies (for example, pathogens, mycorrhizas) compared with a lineage known primarily for saprotrophy (yeasts), suggesting that this coupling is, at least in part, due to direct plant–fungal interactions. These data provide a much-needed look at an understudied dimension of the biota in an important ecosystem and supports the hypothesis that fungal communities are involved in the regulation of tropical tree diversity.     

Can rDNA analyses of diverse fungal communities in soil and roots detect effects of environmental manipulations--a case study from tallgrass prairie

We tested whether fungal communities are impacted by nitrogen deposition or increased precipitation by PCR-amplifying partial fungal rRNA genes from 24 soil and 24 root samples from a nitrogen enrichment and irrigation experiment in a tallgrass prairie at Konza Prairie Biological Station in northeastern Kansas, U.S.A. Obtained fungal sequences represented great fungal diversity that was distributed mainly in ascomycetes and basiodiomycetes; only a few zygomycetes and glomeromycetes were detected. Conservative extrapolated estimates of the fungal species richness suggest that the true richness may be at least twice as high as observed. The effects of nitrogen enrichment or irrigation on fungal community composition, diversity or clone richness could not be unambiguously assessed because of the overwhelming diversity. However, soil communities differed from root communities in diversity, richness and composition. The compositional differences were largely attributable to an abundant, soil-inhabiting group placed as a well-supported sister group to other ascomycetes. This group likely represents a novel group of fungi. We conclude that the great fungal richness in this ecosystem precluded a reliable assessment of anthropogenic impacts on soil or rhizosphere communities using the applied sampling scheme, and that detection of novel fungi in soil may be more a rule than an exception.     

The annual invasive plant Impatiens glandulifera reduces hyphal biomass of soil fungi in deciduous forests

Soil fungi play a crucial role in ecosystem functioning and there is increasing evidence that exotic plants invading forests can affect soil fungal communities. We examined potential effects of the invasive plant Impatiens glandulifera on hyphal biomass of ectomycorrhizal fungi, their genetic diversity and the diversity of other soil fungi in deciduous forests in Switzerland. We compared invaded patches with patches where I. glandulifera had been removed, by establishing pairs of 3-m long transect lines at the edge of seven areas of either type. Along the transects we assessed the length of ectomycorrhizal fungal hyphae using the ‘ingrowth mesh bag method’, and used terminal restriction fragment length polymorphism (T-RFLP) analysis to examine fungal genetic diversity. The invasive plant reduced fungal hyphal biomass by 30–80%: the reduction was largest in the centre of the patch. I. glandulifera did not alter fungal richness, but affected the composition of fungal communities. This is probably the result of a decrease of mycorrhizal fungi, coupled with an increase of saprotrophic fungi. Our findings demonstrate the adverse impacts of an annual invasive plant species on both fungal hyphal biomass and the composition of soil fungal communities. This may negatively affect forest nutrient and carbon cycling, soil stability and the functionality of the fungal community, with major consequences for forest ecosystem functioning.     

Impact of Norway spruce pre-degradation stages induced by Gloeophyllum trabeum on fungal and bacterial communities

In forest ecosystems, fungi are the key actors in wood decay. They have the capability to degrade lignified substrates and the woody biomass of coniferous forests, with brown rot fungi being common colonizers. Brown rots are typically involved in the earliest phase of lignocellulose breakdown, which therefore influences colonization by other microorganisms. However, few studies have focused on the impact of introducing decayed wood into forest environments to gauge successional colonization by natural bacterial and fungal communities following partial decay. This study aimed to address this issue by investigating the bacterial and fungal colonization of Norway spruce (Picea abies) wood, after intermediate and advanced laboratory-based, pre-decay, by the brown rot fungus Gloeophyllum trabeum. Using Illumina metabarcoding, the in situ colonization of the wood blocks was monitored 70 days after the blocks were placed on the forest floor and covered with litter. We observed significant changes in the bacterial and fungal communities associated with the pre-decayed stage. Further, the wood substrate condition acted as a gatekeeper by reducing richness for both microbial communities and diversity of fungal communities. Our data also suggest that the growth of some fungal and bacterial species was driven by similar environmental conditions.     

Illumina高通量测序揭示艾比湖湿地6种盐生植物根际土壤真菌群落组成及多样性

[目的] 通过研究新疆艾比湖湿地不同盐生植物根际土壤真菌的多样性和群落结构,为艾比湖湿地退化恢复工作和真菌深入研究提供理论支持。[方法] 利用高通量测序技术对真菌扩增子ITS1区进行测定,从而分析艾比湖湿地6种盐生植物根际土壤真菌群落多样性,并结合相关土壤理化因子分析环境与真菌群落多样性和丰富度的关联。[结果] 艾比湖湿地6种盐生植物根际土壤真菌群落多样性及丰富度存在差异,碱蓬根际土壤真菌多样性最高,芦苇根际土壤真菌群落丰富度最高。真菌群落组成分析表明,土壤样品中真菌菌落主要隶属于子囊菌门（Ascomycota）和担子菌门（Basidiomycota）,其中子囊菌门为主要优势菌门;链格孢霉属（Alternaria）是6种植物共有的优势菌属,但是其在不同植物之间的丰度存在差异,在戟叶鹅绒藤中的丰度最高,在准噶尔大戟中的丰度最低。pH与真菌多样性呈显著负相关,全磷（TP）与真菌群落丰富度呈显著正相关,pH、电导率（EC）和有机质（OM）对优势菌属的影响最大。[结论] 艾比湖湿地6种盐生植物根际土壤真菌群落组成及多样性具有显著差异,碱蓬和芦苇根际土壤真菌的多样性和丰度高于其他植物,子囊菌门和链格孢霉属是艾比湖湿地的主要土壤真菌门属。研究结果可为艾比湖湿地的生态修复提供理论指导。     

Wildfire severity reduces richness and alters composition of soil fungal communities in boreal forests of western Canada

Wildfire is the dominant disturbance in boreal forests and fire activity is increasing in these regions. Soil fungal communities are important for plant growth and nutrient cycling postfire but there is little understanding of how fires impact fungal communities across landscapes, fire severity gradients, and stand types in boreal forests. Understanding relationships between fungal community composition, particularly mycorrhizas, and understory plant composition is therefore important in predicting how future fire regimes may affect vegetation. We used an extreme wildfire event in boreal forests of Canada's Northwest Territories to test drivers of fungal communities and assess relationships with plant communities. We sampled soils from 39 plots 1 year after fire and 8 unburned plots. High‐throughput sequencing (MiSeq, ITS) revealed 2,034 fungal operational taxonomic units. We found soil pH and fire severity (proportion soil organic layer combusted), and interactions between these drivers were important for fungal community structure (composition, richness, diversity, functional groups). Where fire severity was low, samples with low pH had higher total fungal, mycorrhizal, and saprotroph richness compared to where severity was high. Increased fire severity caused declines in richness of total fungi, mycorrhizas, and saprotrophs, and declines in diversity of total fungi and mycorrhizas. The importance of stand age (a surrogate for fire return interval) for fungal composition suggests we could detect long‐term successional patterns even after fire. Mycorrhizal and plant community composition, richness, and diversity were weakly but significantly correlated. These weak relationships and the distribution of fungi across plots suggest that the underlying driver of fungal community structure is pH, which is modified by fire severity. This study shows the importance of edaphic factors in determining fungal community structure at large scales, but suggests these patterns are mediated by interactions between fire and forest stand composition.     

Tracking Fungal Community Responses to Maize Plants by DNA- and RNA-Based Pyrosequencing

We assessed soil fungal diversity and community structure at two sampling times (t1 = 47 days and t2 = 104 days of plant age) in pots associated with four maize cultivars, including two genetically modified (GM) cultivars by high-throughput pyrosequencing of the 18S rRNA gene using DNA and RNA templates. We detected no significant differences in soil fungal diversity and community structure associated with different plant cultivars. However, DNA-based analyses yielded lower fungal OTU richness as compared to RNA-based analyses. Clear differences in fungal community structure were also observed in relation to sampling time and the nucleic acid pool targeted (DNA versus RNA). The most abundant soil fungi, as recovered by DNA-based methods, did not necessary represent the most “active” fungi (as recovered via RNA). Interestingly, RNA-derived community compositions at t1 were highly similar to DNA-derived communities at t2, based on presence/absence measures of OTUs. We recovered large proportions of fungal sequences belonging to arbuscular mycorrhizal fungi and Basidiomycota, especially at the RNA level, suggesting that these important and potentially beneficial fungi are not affected by the plant cultivars nor by GM traits (Bt toxin production). Our results suggest that even though DNA- and RNA-derived soil fungal communities can be very different at a given time, RNA composition may have a predictive power of fungal community development through time.     

Resorcylic acid lactones from the ginseng pathogen Ilyonectria mors-panacis

Ilyonectria mors-panacis, previously Cylindrocarpon destructans, is the main plant pathogen responsible for the fungal disease ginseng root rot. This economically important disease, also called disappearing root rot, reduces crop yields by an average of 30% at harvest. While the disease is well studied from ecological and genomic perspectives, the role of I. mors-panacis secondary metabolites in the disease process is not well understood. Our previous metabolomics study showed Ilyonectria strains that cause ginseng root rot produce mixtures of putative resorcylic acid lactones, whereas avirulent strains did not, and collectively synthesize fewer metabolites. To confirm these metabolomics findings, we isolated and characterized the secondary metabolites from I. mors-panacis DAOMC 251601, a strain that causes ginseng root rot. From its EtOAc soluble culture filtrate extract, eight resorcylic acid lactones (1-8), including chlorinated and non-chlorinated congeners, were characterized by HRMS and spectroscopic approaches (NMR, OR, UV). The structure of one new metabolite, named radicicol E (1), was elucidated and additional spectroscopic data for the known compound nordinonediol (2) are reported. Further, radicicol (9) production was confirmed by comparison to a standard. The roles that resorcylic acid lactones and the siderophore N,N′,N” triacetylfusarine C have in promoting Ilyonectria ginseng root rot are also discussed.     

Effects of arbuscular mycorrhiza on community composition and seedling recruitment in temperate forest understory

Arbuscular mycorrhizal (AM) fungal communities can influence the species composition of plant communities. This influence may result from effects of AM on seedling recruitment, although the existing evidence is limited to experimental systems. We addressed the impact of AM fungi on the plant community composition and seedling recruitment of two species – Oxalis acetosella and Prunella vulgaris – in a temperate forest understory. We established a field experiment over two years in which soil fertility (using fertilizer to enhance and sucrose to decrease fertility) and the activity of AM fungi (using fungicide) was manipulated in a factorial design. Species richness, diversity and community composition of understory plants were not influenced by soil fertility or AM fungal activity treatments. However, plant community composition was marginally significantly affected by the interaction of these treatments as the effect of AM fungal activity became evident under enhanced soil fertility. Suppression of AM fungal activity combined with decreased soil fertility increased the number of shoots of herbaceous plants. Unchanged activity of AM fungi enhanced the growth of O. acetosella seedlings under decreased soil fertility, but did not influence the growth of P. vulgaris seedlings. We conclude that the role of AM fungi in structuring plant communities depends on soil fertility. AM fungi can have a strong influence on seedling recruitment, especially for those plants that are characteristic of the habitat.     

Ectomycorrhizal fungal communities associated with Masson pine (Pinus massoniana Lamb.) in Pb–Zn mine sites of central south China

To advance our understanding of ectomycorrhizal fungal communities in mining areas, the diversity and composition of ectomycorrhizal fungi associated with Masson pine (Pinus massoniana Lamb.) and soil chemistry were investigated in Taolin lead–zinc (Pb–Zn) mine tailings (TLT), two fragmented forest patches in a Huayuan Pb–Zn mineland (HY1 and HY2), and a non-polluted forest in Taolin in central south China. Ectomycorrhizal fungal species were identified by morphotyping and sequence analyses of the internally transcribed spacer regions of ribosomal DNA. The two study sites in the Huayuan mineland (HY1 and HY2) were significantly different in soil Pb, Zn, and cadmium (Cd) concentrations, but no significant difference was observed in ectomycorrhizal colonization, ectomycorrhizal fungal richness, diversity, or rank–abundance. In addition, the similarity of ectomycorrhizal fungal communities between HY1 and HY2 was quite high (S?rensen similarity index?=?0.47). Thus, the concentration of heavy metals may not be determining factors in the structure of these communities. In the tailings, however, significantly lower ectomycorrhizal colonization and ectomycorrhizal fungal richness were observed. The amounts of Pb and Zn in the tailing sand were higher than the non-polluted forest but far lower than in HY1. Thus, these heavy metals did not account for the reduced colonization and ectomycorrhizal fungal richness in TLT. The ectomycorrhizal fungal community in TLT was dominated by four pioneer species (Rhizopogon buenoi, Tomentella ellisii, Inocybe curvipes, and Suillus granulatus), which collectively accounted for 93.2?% of root tip colonization. The immature soil conditions in tailing (low N and P, sand texture, and lack of organic matter) may only allow certain pioneer ectomycorrhizal fungal species to colonize the site. When soil samples from four sites were combined, we found that the occurrences of major ectomycorrhizal fungal taxa were not clearly related to the concentrations of Pb, Zn, and Cd. In conclusion, our results suggest that ectomycorrhizal fungal communities in mining areas are not necessarily affected by heavy metals themselves but could be largely determined by soil maturity.     

Comparison of root-associated communities of native and non-native ectomycorrhizal hosts in an urban landscape

Non-native tree species are often used as ornamentals in urban landscapes. However, their root-associated fungal communities remain yet to be examined in detail. Here, we compared richness, diversity and community composition of ectomycorrhizosphere fungi in general and ectomycorrhizal (EcM) fungi in particular between a non-native Pinus nigra and a native Quercus macrocarpa across a growing season in urban parks using 454-pyrosequencing. Our data show that, while the ectomycorrhizosphere community richness and diversity did not differ between the two host, the EcM communities associated with the native host were often more species rich and included more exclusive members than those of the non-native hosts. In contrast, the ectomycorrhizosphere communities of the two hosts were compositionally clearly distinct in nonmetric multidimensional ordination analyses, whereas the EcM communities were only marginally so. Taken together, our data suggest EcM communities with broad host compatibilities and with a limited numbers of taxa with preference to the non-native host. Furthermore, many common fungi in the non-native Pinus were not EcM taxa, suggesting that the fungal communities of the non-native host may be enriched in non-mycorrhizal fungi at the cost of the EcM taxa. Finally, while our colonization estimates did not suggest a shortage in EcM inoculum for either host in urban parks, the differences in the fungi associated with the two hosts emphasize the importance of using native hosts in urban environments as a tool to conserve endemic fungal diversity and richness in man-made systems.     

覆盖模式对旱作农田土壤微生物多样性及群落结构的影响

土壤微生物是表征土壤质量的敏感指标，采用Illumina HiSep技术分析不同覆盖方式对半湿润易旱区农田土壤微生物群落结构及多样性的影响，以期从微生物的角度评价农田不同覆盖措施对土壤质量的影响。设3种覆盖模式：平作塑料薄膜覆盖（P）、平作秸秆覆盖（S）和垄膜沟播覆盖（R），以平作不覆盖为对照（CK），研究不同覆盖模式下土壤微生物群落变化，分析各土壤理化因子与微生物群落之间的关系。研究结果表明各覆盖处理显著改变了土壤微生物的群落结构和多样性。所有土壤样品中，细菌群落的优势菌门是变形菌门（Proteobacteria）、酸杆菌门（Acidobacteria）、放线菌门（Actinobacteria），丰度分别为29.69%、28.28%和20.76%，CK处理下较高的土壤pH和低NO₃-N含量抑制了土壤中酸杆菌门（Acidobacteria）的生长繁殖，而放线菌门（Actinobacteria）相对丰度为所有处理中最高。真菌群落的优势菌门是子囊菌门（Ascomycota）、担子菌门（Basidiomycota），丰度分别为59.65%和20.96%，S处理下过低的土壤温度抑制了担子菌门（Basidiomycota）生长和繁殖，其相对丰度为所有处理中最低。与CK相比，P和R处理显著提高土壤细菌的多样性和丰富度；S和R处理下土壤真菌多样性和丰富度显著增加，而P处理的土壤真菌多样性和丰富度均无显著差异。斯皮尔曼相关分析表明土壤细菌多样性主要受土壤含水量（SM）和硝态氮含量（NO₃-N）影响，而土壤真菌多样性主要受土壤温度（ST）、全氮（TN）和硝态氮含量（NO₃-N）影响；RDA分析表明微生物群落结构的变化主要受SM、ST、NO₃-N和TN含量的影响。总的来说，R处理下土壤细菌和真菌的多样性和丰富度较CK处理显著提高，该处理下土壤中担子菌门（Basidiomycota）和球囊菌（Glomeromycota）相对丰度为所有处理中最高，两者分别形成的外生菌根和从生菌根不但促进了根部养分的吸收，而且提高了作物的抗逆性，且结果证明该处理的作物产量为最高，因此在半湿润旱作区推荐采用垄膜沟播覆盖种植方式。     

Soil pH determines fungal diversity along an elevation gradient in Southwestern China

Fungi play important roles in ecosystem processes, and the elevational pattern of fungal diversity is still unclear. Here, we examined the diversity of fungi along a 1,000 m elevation gradient on Mount Nadu, Southwestern China. We used MiSeq sequencing to obtain fungal sequences that were clustered into operational taxonomic units(OTUs) and to measure the fungal composition and diversity. Though the species richness and phylogenetic diversity of the fungal community did not exhibit significant trends with increasing altitude, they were significantly lower at mid-altitudinal sites than at the base. The Bray-Curtis distance clustering also showed that the fungal communities varied significantly with altitude. A distance-based linear model multivariate analysis(DistLM) identified that soil pH dominated the explanatory power of the species richness(23.72%),phylogenetic diversity(24.25%) and beta diversity(28.10%) of the fungal community. Moreover, the species richness and phylogenetic diversity of the fungal community increased linearly with increasing soil pH(P0.05). Our study provides evidence that pH is an important predictor of soil fungal diversity along elevation gradients in Southwestern China.     

Fungal diversity living in the root and sporophore of the endemic Korean fern Mankyua chejuense

Ferns represent the basal group of vascular plants and are known to have fungal interactions with arbuscular mycorrhizal fungi, but diversity of endophytic fungi from ferns is rarely studied. Moreover, fungal diversity associated with ferns is likely underestimated as most studies have been performed based on a microscopic or culture-dependent approach. In this study, we investigated the endophytic fungal diversity within roots and sporophore of an endangered Korean fern (Mankyua chejuense), and compared it to fungi in surrounding soil using a metabarcoding approach. A high diversity of endophytic fungi (236 OTUs), mostly belonging to Ascomycota, was detected and fungal richness and composition were significantly different between habitats. Indicator species analysis showed that endophytic fungi have similar ecological characteristics to fungal species found from other land plants. Our results suggest that various fungal species are associated with ferns, thus understanding fern-associated fungal diversity can have a great implication for fern biology and conservation.     

Fungal community diversity and soil health in intensive potato cropping systems of the east Po valley, northern Italy

An ecological approach was used to investigate the relationship between diversity of soil fungal communities and soil‐borne pathogen inoculum in a potato growing area of northern Italy affected by yield decline. The study was performed in 14 sites with the same tillage management practices: 10 named ‘potato sites’, that for many years had been intensely cultivated with potatoes, and 4 named ‘rotation sites’, subject to a 4‐year rotation without potatoes or any recurrent crop for many years. Fungal communities were recorded using conventional (soil fungi by plate count and endophytic fungi as infection frequency on pot‐grown potato plant roots in soil samples) and molecular approaches [Basidiomycetes and Ascomycetes with specific and denaturing gradient gel electrophoresis (DGGE) analysis]. Diversity of fungal communities in potato sites was significantly lower than that in rotation sites. In addition, fungal communities in rotation sites showed lower Berger–Parker dominance than those in the potato sites, suggesting that rotation sites had a higher diversity as well as a better fungal community balance than potato sites. The ANalysis Of SIMilarity test of soil fungi and root endophytic fungi revealed that the two cropping systems differed significantly for species composition. Root endophytic fungal communities showed a greater ability to colonise potato roots in soil samples from potato sites than those from rotation sites. Moreover, the majority of endophytic root fungal community species in potato sites belonged to the potato root rot complex and storage disease (Colletotrichum coccodes, Fusarium solani and Fusarium oxysporum), while those in rotation sites were mainly ubiquitous or saprobic fungi. Soil rDNA analyses showed that Ascomycetes were much more frequent than Basidiomycetes in all the soils examined. DGGE analysis, with the Ascomycete‐specific primer (ITS1F/ITS4A), did not reveal distinctions between the communities found at the potato and rotation sites, although the same analysis showed differences between the communities of Basidiomycetes (specific primer ITS1F/ITS4B). These findings showed that recurrent potato cropping affected diversity and composition of soil fungal communities and induced a shift in specialisation of the endophytic fungi towards potato.     

Illumina-based analysis of the rhizosphere microbial communities associated with healthy and wilted Lanzhou lily (<Emphasis Type="Italic">Lilium davidii</Emphasis> var. <Emphasis Type="Italic">unicolor</Emphasis>) plants grown in the field

Lanzhou lily (Liliumdavidii var. unicolor) is the best edible lily as well as a traditional medicinal plant in China. The microbes associated with plant roots play crucial roles in plant growth and health. However, little is known about the differences of rhizosphere microbes between healthy and wilted Lanzhou lily (Lilium davidii var. unicolor) plants. The objective of this study was to compare the rhizosphere microbial community and functional diversity of healthy and wilted plants, and to identify potential biocontrol agents with significant effect. Paired end Illumina Mi-Seq sequencing of 16S rRNA and ITS gene amplicons was employed to study the bacterial and fungal communities in the rhizosphere soil of Lanzhou lily plants. BIOLOG technology was adopted to investigate the microbial functional diversity. Our results indicated that there were major differences in the rhizosphere microbial composition and functional diversity of wilted samples compared with healthy samples. Healthy Lanzhou lily plants exhibited lower rhizosphere-associated bacterial diversity than diseased plants, whereas fungi exhibited the opposite trend. The dominant phyla in both the healthy and wilted samples were Proteobacteria and Ascomycota, i.e., 34.45 and 64.01 %, respectively. The microbial functional diversity was suppressed in wilted soil samples. Besides Fusarium, the higher relative abundances of Rhizoctonia, Verticillium, Penicillium, and Ilyonectria (Neonectria) in the wilted samples suggest they may pathogenetic root rot fungi. The high relative abundances of Bacillus in Firmicutes in healthy samples may have significant roles as biological control agents against soilborne pathogens. This is the first study to find evidence of major differences between the microbial communities in the rhizospheric soil of healthy and wilted Lanzhou lily, which may be linked to the health status of plants.