Diversity of root-associated fungi of Rhododendron simsii in subtropical forests: fungal communities with high resistance to anthropogenic disturbances

Species of the Ericaceae or heath family are widely distribute in continental ecosystems and their special ericoid mycorrhizas(ERM)are considered benefi cial to their survival and persistence in variable habitats.Currently,increasing anthropogenic disturbances and improper forest management are aff ecting subtropical forests of China where these native species located.These activities not only aff ect plant communities above-ground,but also impose pressures on microbial communities below-ground.In this study,rootassociated fungal communities of Rhododendron simsii in four forest types under diff erent anthropogenic disturbances were identifi ed using an Illumina Miseq platform,i.e.,old growth forests,secondary forests with one cutting(SECⅠ),secondary forests with two cuttings(SECⅡ),and Chinesefi r plantations(PLF).Intra-and inter-annual variations were analyzed by comparing samples taken in diff erent seasons and years.The results show that:(1)over 1000 OTUs were found in hair roots with most from the division Ascomycota and Basidiomycota belonging to diff erent functional groups;(2)while there were a few indicator OTUs specifi c to diff erent forest types,seasons and years,the proportion of shared taxa was quite large,accounting for 44.9–79.4%of the total OTUs;(3)signifi cantly positive correlations were found between disturbance sensitivity and temporal variations in common fungal orders,and both in major fungal orders were signifi cantly diff erent among fungal functional groups in which putative and possible ERM fungi were highly resistant to disturbances and low temporal variations.The high disturbance resistance and temporal persistence of putative ERM fungi may be essential for the successful adaptation of R.simsii in disturbed subtropical forests of China.

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.

Changes in fungal community and diversity in strawberry rhizosphere soil after 12 years in the greenhouse

Soil fungi play a very important role in the soil ecological environment. In agricultural production, long-term monoculture and continuous cropping lead to changes in fungal community diversity. However, the effects of long-term monoculture and continuous cropping on strawberry plant health and fungal community diversity have not been elucidated. In this study, using high-throughput sequencing(HTS), we compared the fungal community and diversity of strawberry rhizosphere soil after various durations of continuous cropping(0, 2, 4, 6, 8, 10 and 12 years). The results showed that soil fungal diversity increased with consecutive cropping years. Specifically, the soil-borne disease pathogens Fusarium and Guehomyces were significantly increased after strawberry continuous cropping, and the abundance of nematicidal(Arthrobotrys) fungi decreased from the fourth year of continuous cropping. The results of correlation analysis suggest that these three genera might be key fungi that contribute to the changes in soil properties that occur during continuous cropping. In addition, physicochemical property analysis showed that the soil nutrient content began to decline after the fourth year of continuous cropping. Spearman's correlation analysis showed that soil pH, available potassium(AK) and ammonium nitrogen(NH_4^+-N) were the most important edaphic factors leading to contrasting beneficial and pathogenic associations across consecutive strawberry cropping systems.

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.

Response of fungal communities to afforestation and its indication for forest restoration

Soil fungi in forest ecosystems have great potential to enhance host plant growth and systemic ecological functions and services.Reforestation at Saihanba Mechanized Forest Farm,the world's largest artificial plantation,has been integral to global forest ecosystem preservation since the 1950s.To better assess the ecological effects of soil microbiology after afforestation,fungal diversity and community structure(using Illumina sequencing)from forests dominated by Larix gmelinii var.principis-rupprechtii,Pinus sylvestris var.mongolica and Picea asperata,and from grassland were surveyed.In total,4,540 operational taxonomic units(OTUs)were identified,with Mortierella and Solicoccozyma being the dominant genera of grassland soil and Inocybe,Cortinarius,Piloderma,Tomentella,Sebacina,Hygrophorus and Saitozyma dominating the plantation soil.Principle coordinate analysis(PCoA)and co-occurrence networks revealed differences in fungal structure after afforestation.Significantly,more symbiotroph guilds were dominated by ectomycorrhizal fungi in plantations under the prediction of FUNGuild.The community composition and diversity of soil fungi were significantly influenced by pH via redundancy analysis(RDA)and the Mantel test(p<0.01).This finding emphasizes that soil pH has a strong effect on the transition of fungal communities and functional taxa from grassland to plantation,providing a novel indicator for forest restoration.

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.

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.

Analysis of Gut Fungal Community of Cows with Clinical Mastitis

Clinical Mastitis (CM) was one of the most common causes leading health disease in cows. In this article, we gave a new insight to gut fungal community of cows with CM. We chose two cows suffering from CM and four healthy cows from a local cow farm. We classified four healthy cows (H1, H2, H3, H4) into the control group and two cows (CM1, CM2) with CM into the case group. High-throughput sequencing was used to detect the difference of fungal community between the case group and the control group. The difference of gut fungi community was detected both at phylum and genus level. 4 phyla and 98 genera have been detected in the control group and the case group. At the phylum level, we found that the relative abundance of Basidiomycota in the case group was lower than that in the control group. At the genus level, the relative abundance of Saccharomycetales-unclassified and Fungi-unclassified were both higher whereas the relative abundance of Pseudallescheria, Trichosporon, Microascaeae-unclassified, Candida and Scedosprium in the case group was lower compared with the healthy group. Totally, the diversity and abundance of gut fungal community in the case group were lower than the control group. In conclusion, there are some differences of gut fungal community between the control group and the case group and the insights from this study could be used to develop a microbiota-based diagnosis for CM.

Microfungal communities in soil polluted with fluoride

There have been identified three zones according to the degree of soil pollution with fluoride in the impact area of air emissions of the Kandalaksha Aluminium Smelter (Russia): zone of maximum pollution up to 2.5 km from the emission source with the content of fluoride from 5000 to 1200 mg/kg, zone of strong pollution up to 13 km from the plant with the content of fluoride between 1200-400 mg/kg and zone of moderate pollution up to 20 km from the source with content of fluoride between 400-200 mg/kg. Emissions of the aluminium plant have reduced the number and the diversity of fungi and have caused an increase in fungal communities that are potentially pathogenic fungi. The biomass of fungi has decreased in the organic horizon of the maximum polluted soil from 5.4 to 3.6 mg/g. As a whole, emissions from the aluminium plant in the Murmansk region are less toxic for the environment, than emissions of copper-nickel enterprises.

Survey of Annual and Seasonal Fungal Communities in Japanese <i>Prunus mume</i>Orchard Soil by Next-Generation Sequencing

Fungi play a vital role in the management of soil environment. Although various fungal communities are found in soil, it is difficult to determine the fungal community structure in soil. In this study, we conducted a comprehensive survey of fungal communities in Japanese Prunus mume orchard soil from 2010 to 2012 growing seasons using next-generation sequencing technology. Fungal DNA was directly extracted from the soil samples and the internal transcribed spacer 1 region was amplified by PCR and sequenced. We identified 34,826 fungal clone sequences from the soil samples. The fungal clones were sorted into 2132 operational taxonomic units and a majority of the discriminated clone sequences were classified as Ascomycota and Basidiomycota. The number of fungal species belonging to Ascomycota showed increases in June in the three growing seasons. That belonging to Glomeromycota showed increases in August in the three growing seasons. As Ascomycota fungi are wood decomposers and saprotrophs, the results suggested that the number of plant pathogenic fungi increased in Japanese P. mume orchard soil in June. These findings show for the first time the annual and seasonal fungal community structures in Japanese P. mume orchard soil, and are expected to provide valuable clues for improvement when planting new P. mume trees in Japanese orchards.

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.

Significant changes in arbuscular mycorrhizal community and soil physicochemical properties during the saline-alkali grassland vegetation succession

Arbuscular mycorrhizal(AM)fungi are widely distributed in various habitats,and the community composition varies in response to the changing environmental conditions.To explore the response of community composition to the succession of saline-alkali land,soil samples were collected from three succession stages of Songnen saline-alkali grassland.Subsequently,the soil characteristics were determined and the AM fungi in soil samples were analyzed by high-throughput sequencing.Then,the response relationship between community composition and soil characteristics was studied by Canonical correlation and Pearson analyses.The soil properties improved with the succession of saline-alkali grassland.There was no significant difference in alpha diversity between the first and second succession stage(Suaeda glauca and Puccinellia tenuiflora,respectively),and the microbial community had a dense association network at the third stage(Leymus chinensis);in addition,each succession stage had significantly enriched amplicon sequence variants(ASVs)and functional pathways.All the soil properties except cellulase activity had significant effects on community composition.Furthermore,the pH,organic carbon,organic matter,and sucrase activity significantly correlated with alpha diversity indices.These results provide a theoretical basis for realizing the significant changes in AM fungal community and soil properties during the saline-alkali grassland vegetation succession.

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.

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.