Effect of Environmental Factors on Rock-inhabiting Fungal Communities from Brazilian Soapstone Samples

The present study aims to evaluate the environmental effect on fungal community composition associated with biodeterioration occurring in stones （soapstone） at two distinct locations in Minas Gerais State, Brazil： Congonhas city and Sanctuary of Cara^a. Four collections of fungal communities over one year were obtained from both research sites from the soapstone block surfaces exposed for over two decades. The molecular diversity profile of the fungal community at the two localities was obtained by DGGE （Denaturing Gradient Gel Electrophoresis）, and the genomes of the most representative population were sequenced. DGGE showed the formation of two clusters with filamentous fungal communities. Sequencing of the most representative bands revealed the presence of fungi associated with the biodeterioration of soapstone. In addition, many of the identified species were associated with photobionts that could generate lichens, indicating that environmental characteristics affect the occurrence of filamentous fungi, which leads to biodeterioration of stones. Authors＇ study focused on an environmental variation of an extreme habitat for fungi associated with soapstone in the state of Minas Gerais, Brazil and identified the presence of interesting rock-inhabiting fungal communities including species related to lichens, which can accelerate the deterioration of stones by the production of organic acids.

High variation of fungal communities and associated potential plant pathogens induced by long-term addition of N fertilizers rather than P, K fertilizers: A case study in a Mollisol field

Nitrogen(N),phosphate(P),and potassium(K)are the three most important nutrients applied into agricultural soils,but the impacts of their single or combined application on soil fungal community structure and stability are still open questions.Using qPCR and Illumina Miseq sequencing,the variation of soil fungal communities in response to long-term addition of N,P,or K fertilization alone and their combinations in a Mollisol field was investigated in this study.In addition,the fungal community resistance indices and network structure were studied.Results showed that N fertilizations(N,NK,NP and NPK treatments)rather than P,K fertilizations(P,K and PK treatments)significantly increased fungal abundance,but decreased fungal diversity and shifted fungal community structures when compared to non-fertilization(NoF).Additionally,N fertilization treatments presented lower resistance of fungal communities to environment disturbances than those of P,K fertilization treatments.More numbers and higher abundances of changed fungal taxa at the genus and OTU levels were induced by N fertilizations rather than by addition of P,K fertilizers.In addition,N fertilizations induced a more changeable fungal network and complex pathogenic subnetwork with many positive interactions among responding plant pathogens(RP,the changeable plant pathogens induced by fertilizers addition compared to NoF)when compared to P,K fertilizations.These RP directly and negatively influenced fungal community resistance examined by structural equation modeling(SEM),which were indirectly detrimental to soybean yields.Our findings revealed that addition of N fertilizers significantly disturbed fungal communities and promoted pathogenic interactions,and provided insights into the optimization of fertilization strategies toward agricultural sustainability.

Plant-associated fungal communities in the light of meta’omics

Approaches for the cultivation-independent analysis of microbial communities are summarized as meta’omics,which predominantly includes metagenomic,-transcriptomic,-proteomic and-metabolomic studies.These have shown that endophytic,root-associated and soil fungal communities are strongly shaped by associated plant species.The impact of plant identity on the composition of its litterssociated fungal community remains to be disentangled from the impact of litter chemistry.The composition of the plant community also shapes the fungal community.Most strikingly,adjacent plant species may share mycorrhizal symbionts even if the plants usually have different types of mycorrhizal fungi associated with them(ectomycorrhizal,ericoid and arbuscular mycorrhizal fungi).Environmental parameters weakly explain fungal community composition globally,and their effect is inconsistent at local and regional scales.Decrease in similarity among communities with increasing distance(i.e.distance decay)has been reported from local to global scales.This pattern is only exceptionally caused by spatial dispersal limitation of fungal propagules,but mostly due to the inability of the fungi to establish at the particular locality(i.e.environmental filtering or competitive exclusion).Fungal communities usually undergo pronounced seasonal changes and also differ between consecutive years.This indicates that development of the communities is usually not solely cyclic.Meta’omic studies challenge the classical view of plant litter decomposition.They show that mycorrhizal and(previously)endophytic fungi may be involved in plant litter decomposition and only partly support the idea of a succession from an Ascomycota to a Basidiomycota-dominated community.Furthermore,vertical separation of saprotrophic and mycorrhizal species in soil and sequential degradation from easily accessible to‘recalcitrant’plant compounds,such as lignin,can probably not be generalized.The current models of litter decomposition may therefore have to be eventually refined for certain ecosystems and environmental conditions.To gain deeper insights into fungal ecology,a meta’omic study design is outlined which focuses on environmental processes,because fungal communities are usually taxonomically diverse,but functionally redundant.This approach would initially identify dynamics of chemical shifts in the host and/or substrate by metametabolomics.Detected shifts would be subsequently linked to microbial activity by correlation with metatranscriptomic and/or metaproteomic data.A holistic trait-based approach might finally identify factors shaping taxonomic composition in communities against the dynamics of the environmental process(es)they are involved in.

Species richness and species composition of fungal communities associated with cellulose decomposition at different altitudes on the Tibetan Plateau

Aims The aims of this study were to compare the fungal communities developing on cotton strips at three different altitudes on the Tibetan Plateau and to assess the environmental variables influencing them.Methods Cotton strips that had been buried in soil for a year were sampled at three sites at different altitudes(4500,4950 and 5200 m)located on a southeast-facing slope on the Nyainqentanglha Mountains near Damxung.The fungi on the cotton strips were isolated using a modified washing method.The decomposition abilities and colony growth properties of the major species cultured in pure-culture conditions were investigated and compared.Canonical correspondence analysis(CCA)was used to evaluate the relationships between fungal community composition and environmental variables(altitude,soil depth,soil water content[SWC],plant root mass and gravel content).Important Findings A total of 24 species were isolated from the cotton strips,and 12 species occurred frequently and were regarded as major species.The number of fungal species was lower at the 4950-m altitude site than at the other two sites,indicating that not only altitude but also other factors affected the number of species present.All of the major species were able to decompose the cotton strips.In the CCA ordination,automatic forward selection revealed that altitude,SWC and plant root mass significantly affected fungal species composition.Our results suggest thatspecies numberandthecomposition ofcellulolytic fungal communities are highly correlated with environmental variables as well as altitude in the alpine meadow on the Tibetan Plateau.

Contrasting soil fungal communities at different habitats in a revegetated copper mine wasteland

Little is known about the responses of soil fungal communities to revegetation of mine wastelands,representing a major gap in the knowledge needed to improve the performances of revegetation schemes for mine wastelands.To shed some light on this matter,we reestablished 4000 m^(2) of vegetation on an extremely acidic(pH 2.5)copper mine tailings pond and collected soil samples from three different types of habitats:amended layer of the reclaimed tailings(ALRT),unamended layer of the reclaimed tailings(ULRT),and unreclaimed tailings(UT).Soil fungal communities in the 120 samples collected in two consecutive years were characterized via high-throughput sequencing.The fungal diversities at ALRTand ULRT were found to be significantly higher than those at UT.Ascomycota whose relative abundance ranged from 74.5% to 98.4% was the most predominant phylum across all habitats,exhibiting the lowest predominance at ALRT.Two acidophilic fungal genera,Acidomyces and Acidiella,dominated UT with relative abundances being as high as 37.8% and 15.2%,respectively.In contrast,three genera with plant growth-promoting species(Talaromyces,Trichoderma and Penicillium)were abundant at ULRT and ALRT.Remarkably,their relative abundances at ULRTcould be up to 29.0%,26.9% and 9.7%,respectively.The three types of habitats differed considerably in the overall soil fungal community composition at species level,which became more pronounced as time progressed.The abovementioned differences between habitats in soil fungal community features were related to the reduced availability of soil copper and zinc.These results improved our understanding of fungal ecology of mine wastelands.

Effects of multiple but low pesticide loads on aquatic fungal communities colonizing leaf litter

In the first tier risk assessment（RA） of pesticides, risk for aquatic communities is estimated by using results from standard laboratory tests with algae, daphnids and fish for single pesticides such as herbicides, fungicides, and insecticides. However, fungi as key organisms for nutrient cycling in ecosystems as well as multiple pesticide applications are not considered in the RA. In this study, the effects of multiple low pesticide pulses using regulatory acceptable concentrations（RACs） on the dynamics of non-target aquatic fungi were investigated in a study using pond mesocosm. For that, fungi colonizing black alder（Alnus glutinosa） leaves were exposed to multiple, low pulses of 11 different pesticides over a period of 60 days using a real farmer＇s pesticide application protocol for apple cropping.Four pond mesocosms served as treatments and 4 as controls. The composition of fungal communities colonizing the litter material was analyzed using a molecular fingerprinting approach based on the terminal Restriction Fragment Length Polymorphism（t-RFLP） of the fungal Internal Transcribed Spacer（ITS） region of the ribonucleic acid（RNA） gene（s）. Our data indicated a clear fluctuation of fungal communities based on the degree of leaf litter degradation. However significant effects of the applied spraying sequence were not observed. Consequently also degradation rates of the litter material were not affected by the treatments. Our results indicate that the nutrient rich environment of the leaf litter material gave fungal communities the possibility to express genes that induce tolerance against the applied pesticides. Thus our data may not be transferred to other fresh water habitats with lower nutrient availability.

Contrasting soil fungal communities in Mediterranean pine forests subjected to different wildfire frequencies

Mediterranean forest ecosystems are characterized by various vascular plant groups with their associated mycor-rhizae and free living soil fungi with various ecological functions.Fire plays a major role in Mediterranean ecosystem dynamics and impacts both above-and below-ground community structure and functioning.However,studies on the effects induced by altered disturbance regimes(associated with recent land use and climate extremes)on fire ecology and especially on its below-ground impacts are few.The objectives of this study were to evaluate the effects of different wildfire regimes on soil fungal community structure using two different molecular methods.We investigated the long-term effects of wildfire on soil fungal communities associated with Pinus pinaster forests in central Portugal,by comparing the results of denaturing gradient gel electrophoresis(DGGE)-based profiling with those obtained with 454 pyrosequencing.Four forest stands with differing fire history and fire return interval,and vegetation cover(mature forest,early successional stage of pine regeneration,and forest converted to scrubland)were sampled 6 years after the last fire event.The pyrosequencing-based approach indicated ca.eight-fold higher numbers of taxa than DGGE.However,fungal community fingerprinting data obtained for the different study stands with DGGE were congruent with those obtained with pyrosequencing.Both short(7.6 years)and long(24 years)fire return intervals(indicated by the presence of ericaceous shrubs in the understorey)induced a decrease in the abun-dance ratio between basidiomycetes and ascomycetes and appeared to reduce the frequency of ectomycorrhizal fungal species and saprophytes.Wildfire significantly reduced the frequency of late stage successional taxa(e.g.Atheliaceae and Cantharellales)and known or putative saprophytes belonging to the Clavulinaceae and the Archaeorhizomycetaceae.Conversely,early successional fungal species belonging to the Thelephoraceae were favoured by both fire return inter-vals,while the abundance of Cortinarius and Hebeloma,which include several Cistus-specific species,increased with short wildfire return intervals.This last finding highlights the relationship between postfire vegetation composition and cover(vegetation successional stage),and fungal symbionts.We hypothesise that these changes could,in the long term,exhaust the resilience of Mediterranean pine forest vegetation and associated soil fungal communities by preventing pine regeneration.

Polyphenol from foxtail millet bran alleviates experimental colitis in mice by remodulating intestinal fungal community

Inflammatory bowel disease(IBD)is a chronic relapsing-remitting systemic disease of the gastrointestinal tract,characterized by an inflammatory process.Gut mycobiota community dysbiosis has been reported that is closely related to the development of IBD.Our previous findings indicated that polyphenol of the inner shell(BPIS)from foxtail millet bran could restore the gut microbiome and inhibit the progress of colorectal cancer(CRC).In the present study,we studied the anti-inflammatory potential of BPIS in the dextran sodium sulfate(DSS)-induced mouse colitis model.Data suggested that BPIS alleviated experimental colitis by restoring body weight,colonic length and protecting the epithelial architecture from damage by DSS.Moreover,we found that BPIS strengthened the gut barrier function and inhibited the activation of Wnt1/β-catenin pathway.Gene sequence analysis indicated that BPIS remodeled the overall structure of the gut mycobiota from colitis mice toward that of the normal counterparts,including 1 phylum and 9 genera.Interestingly,BPIS significantly increased the abundance of Aspergillus ruber.It further verified that BPIS significantly promoted the growth of A.ruber in vitro.Collectively,BPIS has great potential to develop into an effective against IBD drug.

Impact of Vegetation Restoration on Soil Fungal Community Structure in Karst Rocky Desertification Areas

In this paper,managed forest(MF)and natural forest(NF)in the Huajiang Demonstration Zone of Guanling,Guizhou were selected as research objects,and cropland(CL)was taken as control.High-throughput sequencing technology was used to study the characteristics of fungal community composition and species diversity in the surface(0-10 cm)soil of each restoration measure,in order to reveal the dominant soil fungal groups and fungal community composition in karst rocky desertification areas,which was conducive to a more comprehensive understanding of the soil conditions of different vegetation restoration measures.Research has shown that vegetation restoration significantly affected the diversity of soil fungal community,with significant increases in Sob index,Ace index,and Chao index.The vegetation restoration has significantly changed the composition of fungal community.The dominant fungi in the CL topsoil are Sordariomycetes(62.28%),Dothideomycetes(12.34%),and Eurotiomycetes(9.12%);the dominant fungi in the MF soil are Sordariomycetes(45.05%),Dothideomycetes(14.74%),and Mortierellomycetes(10.40%);the dominant fungi in the NF soil are unclassified fungal community(26.38%),Sordariomycetes(19.78%),and Agaricomycetes(13.82%).Vegetation restoration has changed the key fungal groups in the soil.Sordariomycetes,Fusarium,and Setophoma are the key dominant fungal groups in CL soil;Dioszegia is key dominant fungal group in MF soil;c_unclassified_k_Fungi,p_unclassified_k_Fungi,o_unclassified_k_Fungi,f_unclassified_k_Fungi,g_unclassified_k_Fungi,Teichospora,and Diaporthe are key dominant fungal groups in NF soil.

Conversion of pure Chinese fir plantation to multi-layered mixed plantation enhances the soil aggregate stability by regulating microbial communities in subtropical China

Background:Soil aggregates are the basic units of soil structure,and their stability is a key indicator of soil quality and capacity to support ecosystem functions.The impacts of various environmental factors on soil aggregates have been widely studied.However,there remains elusive knowledge on the synergistic effects of changing forest stand structure on soil aggregate stability(SAS),particularly in subtropical China where soil erosion remains a critical issue.Methods:We investigated variations in the components of soil humus(HS),including humic acids(HAs),fulvic acids(FAs),and humins(HMs),under pure Chinese fir(Cunninghamia lanceolata)plantation(PP)and multilayered mixed plantation(MP)comprising C.lanceolata,Castanopsis hystrix,and Michelia hedyosperma.The state of soil aggregate stability,was determined by three separate methods,i.e.,dry-sieving,wet-sieving,and the Le Bissonnais.High-throughput sequencing was used to determine the diversity and composition of microbial communities under PP and MP.We then built partial least squares path models(PLS-PM)for assessing the responses of SAS to the variations in soil microorganisms and HS components.Results:The MP stands had significantly greater SAS(P<0.05),higher content of HAs and more rapid organic matter humification within aggregates,than the PP stands.High-throughput sequencing confirmed that the Pielou andα-diversity index values(Chao1 and Shannon)for fungi were all significantly higher under MP than under PP,while no marked difference was found in bacterialα-diversity between the two plantation types.Moreover,there were markedly greater abundance of three bacterial phyla(Verrucomicrobia,Chloroflexi,and Gemmatimonadetes)and three fungal phyla(Ascomycota,Kickxellomycota,and Glomeromycota),and significantly less abundance of two bacterial phyla(Planctomycetes and Firmicutes)and four fungal phyla(Basidiomycota,Mortierellomycota,Mucoromycota,and Rozellomycota)under MP than under PP.The Chloroflexi and Ascomycota phyla appeared to be the primary drivers of soil aggregate distribution.Our findings revealed that the promotion of SAS under MP was mainly driven by increased soil organic matter(SOM)content,which altered bacterial communities and enhanced fungal diversity,thereby increasing HAs content and the rate of organic matter humification.Conclusions:Considering the combined effects of enhanced soil quality,productivity,and relevant economic costs,introducing broadleaved tree species into Chinese fir plantations can be an effective strategy for stabilizing soil structure against erosion in subtropical China.Our study elucidated the controls on variations of SAS in Chinese fir-dominated plantations and demonstrated the benefit of converting pure Chinese fir plantation to multi-layered mixed plantations in increasing soil structural stability and improving site quality.

Effects of Consecutively Monocultured Rehmannia glutinosa L.on Diversity of Fungal Community in Rhizospheric Soil

Continuous monoculture problems, or replanting diseases, are one of the key factors affecting productivity and quality of Chinese medicinal plants. The underlying mechanism is still being explored. Most of the studies on continuous monoculture ofRehmannia glutinosa L. are focused on plant nutritional physiology, root exudate, and its autotoxieity. However, the changes in the diversity of microflora in the rhizosphere mediated by the continuous monoculture pattern have been remained unknown. In this study, terminal restriction fragment length polymorphism （T-RFLP） technique was used for fingerprinting fungal diversity in the rhizosphere soil sampled from the fields ofR. glutinosa monocultured for 1 and 2 yr. The results showed that the structure of fungal community in consecutively moncultured rhizosphere soil was different from that in control soil （no cropping soil）, and varied with the consecutive monoeulture years （1 and 2 yr）. The comprehensive evaluation index （D） of fungal community estimated by principal component analysis of fragment number, peak area, Shannon-Weiner index, and Margalef index was higher in 1 yr monoculture soil than that in 2 yr monoculture soil, suggesting that consecutive monoculture of R. glutinosa could be a causative agent to decrease the diversity of fungal community in the rhizosphere soil.

Response of soil fungal community to long-term chromium contamination

To further study the fungal community in heavy metal contaminated ecosystems,soil samples were collected from an abandoned chromium(Cr)factory,and fungal community was analyzed by Illumina sequencing of Internal Transcribed Spacer(ITS)amplicons.The results showed that Cr contamination changed the composition and structure of soil fungal community,but didn’t change the diversity.Fungus showed various responses to Cr contamination.LEfSe analysis revealed that the biomarker changed a lot in the Cr-contaminated samples in comparison with that in the control samples.The changes in fungal community may be caused by the direct toxic effects on fungi by high concentration of Cr and the significant change in soil properties resulting from Cr contamination.Among all the Cr fractions,organic matter-bound Cr and exchangeable Cr showed significant effects on the fungal community and organic matter also showed a significant effect on soil fungal community.

A comprehensive analysis of the response of the fungal community structure to long-term continuous cropping in three typical upland crops

Certain agricultural management practices are known to affect the soil microbial community structure;however,knowledge of the response of the fungal community structure to the long-term continuous cropping and rotation of soybean,maize and wheat in the same agroecosystem is limited.We assessed the fungal abundance,composition and diversity among soybean rotation,maize rotation and wheat rotation systems and among long-term continuous cropping systems of soybean,maize and wheat as the effect of crop types on fungal community structure.We compared these fungal parameters of same crop between long-term crop rotation and continuous cropping systems as the effect of cropping systems on fungal community structure.The fungal abundance and composition were measured by quantitative real-time PCR and Illumina MiSeq sequencing.The results revealed that long-term continuous soybean cropping increased the soil fungal abundance compared with soybean rotation,and the fungal abundance was decreased in long-term continuous maize cropping compared with maize rotation.The long-term continuous soybean cropping also exhibited increased soil fungal diversity.The variation in the fungal community structure among the three crops was greater than that between long-term continuous cropping and rotation cropping.Mortierella,Guehomyces and Alternaria were the most important contributors to the dissimilarity of the fungal communities between the continuous cropping and rotation cropping of soybean,maize and wheat.There were 11 potential pathogen and 11 potential biocontrol fungi identified,and the relative abundance of most of the potential pathogenic fungi increased during the long-term continuous cropping of all three crops.The relative abundance of most biocontrol fungi increased in long-term continuous soybean cropping but decreased in long-term continuous maize and wheat cropping.Our results indicate that the response of the soil fungal community structure to long-term continuous cropping varies based upon crop types.

Soil Cellulase Activity and Fungal Community Responses to Wetland Degradation in the Zoige Plateau, China

Four soil types(peat, marsh, meadow, and sandy) in the Zoige Plateau of China are associated with the severity of wetland degradation. The effects of wetland degradation on the structure and abundance of fungal communities and cellulase activity were assessed in these 4 soil types at 3 depths using DGGE(Denatured Gradient Gel Electrophoresis), q PCR(Quantitative Real-time PCR),and 3,5-dinitrosalicylic acid assays. Cellulase activity and abundance of the fungal community declined in parallel to the level of wetland degradation(from least to most disturbed). DGGE analysis indicated a major shift in composition of fungal communities among the4 soil types consistent with the level of degradation.Water content(WC), organic carbon(OC), total nitrogen(TN), total phosphorus(TP), available nitrogen(AN), and available phosphorus(AP) were strongly correlated with cellulase activity and the structure and abundance of the fungal community.The results indicate that soil physicochemical properties(WC, OC, TN, TP, AN, and AP), cellulase activity, and diversity and abundance of fungal communities are sensitive indicators of the relative level of wetland degradation. WC was the major factorinvolved in Zoige wetland degradation and lower WC levels contributed to declines in the abundance and diversity of the fungal community and reduction in cellulase activity.

Soil Fungal Diversity and Community Composition in Response to Continuous Sweet Potato Cropping Practices

Soil fungi are extremely important for maintaining soil health and plant production in agricultural systems.Currently,the effect of continuous cropping of sweet potato on soil fungal communities and physiochemical parameters has not been well documented.In the present study,four sweet potato fields consecutively monocultured for 1,2,3,and 4 years were selected to investigate the effect of monoculture on soil fungal communities through Illumina MiSeq sequencing.Continuous cropping of sweet potatoes dramatically altered the fungal community composition,whereas fungal diversity was almost unchanged.Ascomycota and Basidiomycota were the most abundant phyla in all soil samples,accounting for 32.59%and 21.14%of the average relative abundance,respectively.The abundance of some potential pathogens,such as Ascobolus spp,specifically Ascobolus stercorarius,and some unknown fungi increased significantly as the sweet potato monoculture period increased,and their presence were highly positively correlated with disease incidence.In contrast,Basidiomycota,Bullera,Fusarium and Trichocladium most likely play roles as antagonists of sweet potato disease development,as their relative abundance decreased significantly over time and were negatively correlated with disease incidence.Redundancy and correlation analyses revealed that soil pH and organic carbon content were the most important factors driving these changes.Our findings provided a dynamic overview of the fungal community and presented a clear scope for screening beneficial fungi and pathogens of sweet potato.

Promoting the Growth of Pinus sylvestris var.mongolica Seedlings and Improving Rhizosphere Fungal Community Structure through Interaction between Trichoderma and Ectomycorrhizal Fungi

In this study,pot experiments were conducted on the seedlings of Pinus sylvestris var.mongolica to study the influence of Trichoderma(Trichoderma harzianum E15)and Ectomycorrhizal fungi(Suillus luteus N94)on the growth of these seedlings.In particular,the effects of these fungi on the fungal community structure in the rhizosphere soil of the seedlings were investigated.Inoculation with Trichoderma harzianum E15 and Suillus luteus N94 significantly(P<0.05)promoted the growth of the Pinus sylvestris seedlings.The non-metric multidimensional scaling(NMDS)results indicated a significant difference(P<0.05)between the fungal community structures in the rhizosphere soil of the annual and biennial seedlings.In the rhizosphere soil of annual seedlings,the main fungi were Ascomycota,Basidiomycota,Zygomycota.Ascomycota,Basidiomycota,Mortierellomycota,and p-unclassified-k-Fungi were the main fungi in the rhizosphere soil of biennial seedlings.The dominant genus in the rhizosphere soil and a key factor promoting the growth of the annual and the biennial seedlings was Trichoderma,Suillus,respectively.Both of them were negatively correlated with the relative abundance of microbial flora in the symbiotic environment.Trichoderma had a significant promoting effect on the conversion of total phosphorus,total nitrogen,ammonium nitrogen,nitrate nitrogen,and the organic matter in the rhizosphere soil of the seedlings,while Suillus significantly promoted the conversion of organic matter and total phosphorus.

Soil pH and dissolved organic carbon shape microbial communities in wetlands with two different vegetation types in Changdu area,Tibet

Soil microorganisms play pivotal roles in element biogeochemical cycling and ecological functions in wetland ecosystem,which may affect global climate change.Variations in biotic and abiotic factors are known to affect soil microbial diversity,community structure and the corresponding functions.However,the relative importance of these biotic and abiotic factors on wetland soil microbial diversity and community structure on the QinghaiTibet Plateau remains poorly understood.In this study,we explored soil bacterial and fungal diversity and composition of five wetlands under two vegetation types(herbs vs Hippophae thibetana)in Changdu area,Tibet,through Illumina high throughput sequencing analysis of 16S rRNA for bacteria and internal transcribed spacer(ITS)for fungi.Results showed that soil bacterial alpha diversity was higher in H.thibetana dominated wetlands and was significantly and positively correlated with soil pH.No difference was detected in the soil fungal alpha diversity among samples and between vegetation types.The dominant soil bacterial phyla were Proteobacteria,Actinobacteria,Acidobacteria,and Firmicutes.While Ascomycota,Basidiomycota and Mucoromycota were the dominant fungal phyla.Soil bacterial and fungal community structures were significantly distinct by vegetation types.In addition,redundancy analysis indicated that soil pH was the key factor shaping soil bacterial community structure.Nevertheless,soil p H showed no effect on fungal community.Instead,soil dissolved organic carbon was the major factor contributing to soil fungal community structure.This study emphasized that wetland soil microbial communities were distinct by vegetation types and the driving factors of microbial beta diversity between bacterial and fungal community were also different in wetlands in Changdu area.

Fungal community structure analysis of peanut pod rot in soil in Hebei Province,China

In recent years,peanut yield and quality are more seriously affected by pod rot disease in China.However,managing this disease has proven challenging due to the wide host range of its pathogens.In this study,four soil samples were collected from fields with pod rot disease in Hebei Province,and 454 pyrosequencing was used to analyze the fungal communities structure within them.All 38490 ITS high-quality sequences were grouped into 1203 operational taxonomic units,the fungal community diversity of four soil samples was evaluated and compared using Shannon index and Simpson index.The results showed that members of Ascomycota were dominant,followed by Basidiomycota.According to the BLAST results at the species level,Guehomyces had the highest abundance,accounting for about 7.27%,followed by Alternaria,Fusarium,and Davidiella.The relative abundance of Fusarium oxysporum isolated from rotting peanuts in soil with peanut rot was higher than that in the control,indicating that Fusarium oxysporum might be one of the main pathogenic fungus of peanut rot in this area.This study delved into the broader fungal community associated with peanut pod rot,providing a theoretical foundation for preventing and treating this disease in agriculture.

Effects of Tillage Depth on Nutrients and Microbial Communities in Tobacco-Planting Soil

The implementation of appropriate tillage practices is of great significance for agricultural production. However, the effects of different tillage depths on soil nutrients content and microbial communities in tobacco-planting soils are still lacking systematic research. In this study, three different tillage depths of 15 cm (T1), 20 cm (T2), and 30 cm (T3) were set up for field experiments in Liupanshui, Guizhou Province, to explore the effects of tillage depth on tobacco-planting soil nutrients and bacterial and fungal communities based on 16S rRNA and ITS sequencing and figure out the key factors affecting soil microbial communities. The results showed that T2 and T3 increased the contents of organic matter, total nitrogen, total phosphorus, available phosphorus, and available potassium in tobacco-planting soil, and increased the diversity of bacterial communities compared with T1. There was no significant difference in the structure of bacterial and fungal communities in different tillage depth treatments, but some dominant genera were significantly enriched in T2 and T3. Desulfobacter, Setophoma, Humicola, and Acremonium were significantly enriched in T2. Chthonomonas and Fusarium were significantly enriched in T3. These genera favor the decomposition of organic matter and the cycling of nutrients, and control soil pests and diseases. Redundancy analysis indicated that TP and AK were the key factors influencing the dominant genera of bacteria and fungi. This study provides a scientific basis for the selection of soil tillage depth for tobacco production in this region.

Spore production in the solid-state fermentation of stevia residue by Trichoderma guizhouense and its effects on corn growth

Trichoderma is an important and widely used plant growth-promoting fungus(PGPF).In this study,stevia residue amended with amino acids hydrolyzed from animal carcasses was used for the production of Trichoderma guizhouense NJAU 4742 by solid-state fermentation,and then its potential to promote corn plant growth was evaluated in combination with chemical fertilizer(CF)or organic fertilizer(OF).The highest spore number of 7×10^(9) CFU g^(–1) fresh weight was obtained under the following optimal parameters:material ratio of 50%(stevia residue:rice bran=1:1),pH value of 3.0(amended with 6.67%amino acids),initial moisture content of 60%,inoculum size of 10%,material thickness of 3 cm and an incubation time of 4 days.The aboveground corn plant biomass obtained with T.guizhouense applied alone and with CF treatments were slightly higher than those of no fertilizer control and CF treatments,respectively.However,T.guizhouense applied with OF significantly(P<0.05)increased aboveground biomass compared to OF and yielded the highest aboveground biomass among all the treatments.Moreover,T.guizhouense applications primarily influenced the fungal bulk soil community composition,among which three OTUs(OTU_(2) and OTU_(9) classified as Chaetomium,and OTU_(4)classified as Trichoderma)were stimulated in both bulk and rhizosphere soil.Notably,a specific OTU_(3)(Phymatotrichopsis)was only stimulated by T.guizhouense applied with OF,possibly leading to high soil productivity.These results show that it is feasible to employ stevia residue in the eco-friendly fermentation of T.guizhouense,which is strongly suggested for enhancing OF applications.