This study is aimed at identifying and determining the percentage of occurrence frequency of cellulose decomposing soil fungi. The soil samples were inoculated into culture plates prepared in Sabouraud medium under st...This study is aimed at identifying and determining the percentage of occurrence frequency of cellulose decomposing soil fungi. The soil samples were inoculated into culture plates prepared in Sabouraud medium under sterilized conditions and incubated at 30 ℃ for 4 to 7 d. The identified fungal species were incubated in self-designed cellulose medium for testing their cellulolytic ability. Forty-two species, including2 nova species, representing sixteen genera showed growth and sporulation in the cellulose medium. Most of the isolated species were from genus Aspergillus and Penicillium. Aspergillus niger and Mucor hiemalis showed highest occurrence frequency (45% and 36% respectively), as these species were collected from about 80% of soil samples. Being agar free and cheaper, the new fungal medium designed showed results equivalent to Sabouraud medium.展开更多
Abstract: We assessed soil fungal diversity in the dry deciduous forest ofa Bhadra Wildlife Sanctuary of the Western Ghats (210.31 m a.s.1.; N 13044' and E75°37′). Soil samples were collected by random mixed...Abstract: We assessed soil fungal diversity in the dry deciduous forest ofa Bhadra Wildlife Sanctuary of the Western Ghats (210.31 m a.s.1.; N 13044' and E75°37′). Soil samples were collected by random mixed sampling during winter (November, 2008), summer (March, 2009) and monsoon (August, 2009) seasons, and physico-chemical parameters were recorded. During winter, summer, and monsoon seasons, 49, 45 and 49 of fungal species belongs to 20, 18 and 19 of genera were isolated, respectively. Isolated soil fungi were mainly of the Mitosporic fungi, followed by Zygomycotina, Ascomycotina, Oomycotina and Coelomycetes. Indices of diversity, dominance and fisher alpha during winter, summer and monsoon seasons were 3.756, 3.638 and 3.738 (H), 0.9737, 0.9694 and 0.9726 (I-D) and 18.84, 29.83 and 19.46 (a), respectively. Spear- man's (r) correlation coefficient of fungal population with physicochemical parameters of soils showed significantly positive and negative correlations (p〈0.01) during winter, summer and monsoon seasons. Physico-chemical soil parameters played an important role in the occurrence, diversity, distribution, and relative abundance of fungal species in the tropical dry deciduous forest soil.展开更多
This study aims to investigate the abundance of AMF according to soil properties and altitudes in different cacao plantations of Cameroon. Physico-chemical analyses were made on soil samples collected from three agro-...This study aims to investigate the abundance of AMF according to soil properties and altitudes in different cacao plantations of Cameroon. Physico-chemical analyses were made on soil samples collected from three agro-ecological zones. Soil samples were also used to evaluate directly the AMF abundance following the various altitudes and after trapping by sorghum plant. The results showed that soil properties, AMF spore abundances and colonization fluctuated significantly at different altitudes. The most represented texture was sandy loam. The bimodal zone presented a homogeneous texture (sandy loam) in all its localities. Cacao soil chemical characteristics showed that, the highest nitrogen rate (0.47%;p 0.05, Scott-Knott test) was recorded at Melong in a monomodal zone while Tonga in the Western highlands displayed the lowest rate (0.13%). Soil P concentration was significantly high in monomodal zones (Mbanga and Melong). Soil pH level indicated that the soil from Tonga in the Western highlands was neutral (pH = 6.67), and soils of other localities under study were acidic with the lowest (4.75) pH level recorded at Melong in a monomodal zone. In soil samples, the highest spore density (1.03 spores/g soil) was observed at Ntui in Bimodal zone, while the lowest spore density (0.26 spores/g soil) was observed at Bafang in the Western highlands. Root colonization showed that the sample from Bokito in a bimodal zone displayed the best frequency of mycorrhization (86.11%) while the sample from Bafang in the Western highlands recorded the lowest (27.11%). The PCA analysis highlighted that available phosphorus, pH and altitude all strongly correlated with AMF root colonization ability and can be used as a predictor of AMF colonization ability in cacao rhizosphere.展开更多
In order to optimize polymerase chain reaction(PCR) amplification of the internal transcribed spacer(ITS) rDNA region from fungi found in black soil in North China,an orthogonal experimental design [L16(45)] was...In order to optimize polymerase chain reaction(PCR) amplification of the internal transcribed spacer(ITS) rDNA region from fungi found in black soil in North China,an orthogonal experimental design [L16(45)] was used to evaluate five factors(template,Mg2+,dNTP,Taq DNA polymerase,and primer) from four levels.Subsequently,the optimal annealing temperature,annealing time,extension time and cycle numbers were evaluated.The results showed that the optimized PCR solution for amplification of ITS region comprised 5 μL 10× buffer,30 ng soil DNA template,3.0 mmol·L-1 Mg2+,0.2 mmol·L-1 dNTPs,0.1 μmol·L-1 each forward and reverse primer,and 2.0 U Taq enzyme in 50 μL reaction volume.The optimal thermal cycling protocol consisted of initial melting at 94℃ for 5 min,followed by 35 cycles at 94℃ for 30 s,56℃ for 30 s,72℃ for 90 s,and a final extension of 72℃ for 10 min.展开更多
In semi-arid region of northwestern China, underground mining subsidence often results in decreased vegetation coverage, impoverishment of soil fertility and water stress. In addition, the physical-chemical and biolog...In semi-arid region of northwestern China, underground mining subsidence often results in decreased vegetation coverage, impoverishment of soil fertility and water stress. In addition, the physical-chemical and biological properties of soil also change, resulting in more susceptible to degradation. In particular, subsidence causes disturbance of the symbioses of plant and microbe that can play a beneficial role in the establishment of vegetation communities in degraded ecosystems. The objective of this study was to evaluate the effects of revegetation with exotic arbuscular mycorrhizal fungi(AMF) inoculum on the chemical and biological properties of soil over time in mining subsidence areas. Soils were sampled at a depth up to 30 cm in the adjacent rhizosphere of Amorpha fruticose Linn. from five reclaimed vegetation communities in northwestern China. In August 2015, a field trial was set up with five historical revegetation experiments established in 2008(7-year), 2011(4-year), 2012(3-year), 2013(2-year) and 2014(1-year), respectively. Each reclamation experiment included two treatments, i.e., revegetation with exotic AMF inoculum(AMF) and non-AMF inoculum(the control). Root mycorrhizal colonization, glomalin-related soil protein(GRSP), soil organic carbon(SOC), soil nutrients, and enzyme activities were also assessed. The results showed that mycorrhizal colonization of inoculated plants increased by 33.3%–163.0% compared to that of non-inoculated plants(P<0.05). Revegetation with exotic AMF inoculum also significantly improved total GRSR(T-GRSP) and easily extracted GRSP(EE-GRSP) concentrations compared to control, besides the T-GRSP in 1-year experiment and the EE-GRSP in 2-year experiment. A significant increase in SOC content was only observed in 7-year AMF reclaimed soils compared to non-AMF reclaimed soils. Soil total N(TN), Olsen phosphorus(P) and available potassium(K) were significantly higher in inoculated soil after 1–7 years of reclamation(except for individual cases), and increased with reclamation time(besides soil Olsen P). The exotic AMF inoculum markedly increased the average soil invertase, catalase, urease and alkaline phosphatase by 23.8%, 21.3%, 18.8% and 8.6%, respectively(P<0.01), compared with the control. Root mycorrhizal colonization was positively correlated with soil parameters(SOC, TN and soil available K) and soil enzyme activities(soil invertase, catalase, urease and alkaline phosphatase) in both AMF and non-AMF reclaimed soils(P<0.05), excluding availableK in non-AMF reclaimed soils. T-GRSP(P<0.01) and EE-GRSP(P<0.05) were significantly correlated with the majority of edaphic factors, except for soil Olsen P. The positive correlation between root mycorrhizal colonization and available K was observed in AMF reclaimed soils, indicating that the AMF reclaimed soil with a high root mycorrhizal colonization could potentially accumulate available K in soils. Our findings concluded that revegetation with exotic AMF inoculum influenced soil nutrient availability and enzyme activities in the semi-arid ecosystem, suggesting that inoculating AMF can be an effective method to improve soil fertility and support restoration of vegetation communities under poor conditions like soil nutrient deficiency and drought.展开更多
138 soil samples were collected from various loca-tions in Ladakh, a cold desert in the Himalayan region, India and the samples were screened for the presence of keratinophilic fungi using the hair baiting techniques....138 soil samples were collected from various loca-tions in Ladakh, a cold desert in the Himalayan region, India and the samples were screened for the presence of keratinophilic fungi using the hair baiting techniques. 58 isolates were recovered and identified. The cultures were identified based on their macro- and micro-morphological features. A total of six genera and fourteen species were isolated namely Amauroascus kuehnii (0.72%), Aphanoascus keratinophilus (4.34%), Aphanoascus terreus (2.17%), Auxarthron alboluteum (0.72%), Auxarthron conjugatum (0.72%), Chrysosporium articulatum (0.72%), Chrysosporium mephiticum (0.72%), Chrysosporium minutisporosum (2.17%), Chrysosporium siglerae (0.72%), Chrysosporium sp. (1.44%), Chrysosporium tropicum (15.94 %), Chrysosporium submersum (3.62%), Chrysosporium state of Ctenomyces serratus (6.52%) and Geomyces pannorum (1.45%). The present study shows that keratinophilic fungi exist in the cold desert of Ladakh.展开更多
Screening was done for the isolation of effective lignin degraders from the forest soil samples, by providing lignin as a carbon source through the enrichment method, which leads to the isolation of 8 effective fungal...Screening was done for the isolation of effective lignin degraders from the forest soil samples, by providing lignin as a carbon source through the enrichment method, which leads to the isolation of 8 effective fungal isolates among 14 isolates. Submerged fermentation was done for the production of ligninolytic enzymes with the effective microorganisms by providing Guiaicol as a carbon source. The assay of laccase, lignin peroxidise activity and specific activity was done after the incubation intervals of 2, 4, 6, 7, 8, 10 and 12 days at 27±2℃ under shake culture condition. Partially purified protein content was estimated by using Lowry's method. Pleurotus sp. and Phanerochaetae chrysosporium are more effective at the 2nd and 7th days of incubation for the production of laccase and lignin peroxidases among the effective isolates.展开更多
Two compounds were isolated from ethyl acetate extract of the fermentation of fungus 07-11, which obtained from the soil of Yunnan Province. They were identified as N-(4-hydroxy-2-methoxyphenyl) acetamide (1) and ergo...Two compounds were isolated from ethyl acetate extract of the fermentation of fungus 07-11, which obtained from the soil of Yunnan Province. They were identified as N-(4-hydroxy-2-methoxyphenyl) acetamide (1) and ergosta-7,22-diene-3,6-dione (2) respectively on the basis of spectral analyses and physical and chemical identifications. Compound 1 was a new natural product. Compound 2 was firstly isolated from its genus. Spectral data of 1 and complete 1H NMR data of 2 were reported for the first time.展开更多
We examined suitability of arbuscular mycorrhizal fungi (AMF) associated with cool-season nonnative forages on reclaimed surface-mined land in southeast Ohio for establishment of native warm-season grasses. The goal o...We examined suitability of arbuscular mycorrhizal fungi (AMF) associated with cool-season nonnative forages on reclaimed surface-mined land in southeast Ohio for establishment of native warm-season grasses. The goal of establishing these grasses is to diversify a post-reclamation landscape that is incapable of supporting native forest species. A 16-week glasshouse study compared AMF from a 30-year reclaimed mine soil (WL) with AMF from native Ohio tallgrass prairie soil (CL). Four native grasses were examined from seedling through 16 weeks of growth. Comparisons were made between CL and WL AMF on colonized (+AMF) and non-colonized plants (–AMF) at three levels of soil phosphorus (P). Leaves were counted at 4 week intervals. Shoot and root biomass and percent AMF root colonization were measured at termination. We found no difference between WL and CL AMF. Added soil P did not reduce AMF colonization, but did reduce AMF efficacy. Big bluestem (Andropogon gerardii Vitman), Indiangrass (Sorghastrum nutans (L.) Nash), and tall dropseed (Sporobolus asper (Michx.) Kunth) benefited from AMF only at low soil P while slender wheatgrass (Elymus trachycaulus (Link) Gould ex Shinners) exhibited no benefit. Establishment of tallgrass prairie dominants big blue-stem and Indiangrass would be supported by the mine soil AMF. It appears that the non-native forage species have supported AMF equally functional as AMF from a regionally native tallgrass prairie. Tall dropseed and slender wheatgrass were found to be less dependent on AMF than big bluestem or Indiangrass and thus would be useful in areas with little or no AMF inoculum.展开更多
Fires are an important factor impacting forest ecosystems of Daxing'anling and have a significant effect on soil microbial community structure.In this study,highthroughput sequencing for 16 S rDNA and ITS rDNA wer...Fires are an important factor impacting forest ecosystems of Daxing'anling and have a significant effect on soil microbial community structure.In this study,highthroughput sequencing for 16 S rDNA and ITS rDNA were applied to analyze the changing characteristics and driving factors of bacterial and fungal community structures in burned areas with different fire severity.PICRUSt2 software was used to predict the functional characteristics of burned areas with different fire severity.The purpose was to unveil the responsive relationships among the structure and function of bacterial and fungal communities,fire severity,and post-disturbance restoration times.After high severity fires,the destruction of surface vegetation and loss of soil nutrients reduced the diversity and abundance of soil bacteria and fungi.The soil bacteria community structure,which was dominated by Acidobacteria,Proteobacteria,and Actinobacteria,changed to be dominated by Proteobacteria and Chloroflexi.As well,soil fungal community changed from domination by Helotiales,Eurotiales and Russulales to domination by Archaeorhizomycetales and Helotiales.Over time,soil bacterial community was gradually restored to prefire levels 30 years after the fire.Soil fungal community changed and failed to restore to pre-fire levels after 30 years.After low/intermediate severity fires,environmental factors were relatively unchanged so that soil bacteria diversity and abundance increased,optimizing community composition.The diversity and abundance of soil fungi decreased and the community structure changed slightly.Over time,both bacterial and fungal communities were gradually restored to pre-fire levels 30 years after the fire.After fire disturbance,with increasing severity,soil carbon fixation,lignin degradation,mineralization of organic nitrogen and hydrolysis of organic phosphorus are enhanced.Denitrification is weakened.Therefore,forest fires have certain positive effects on carbon,nitrogen and phosphorus cycles where soil bacteria and fungi are involved.展开更多
As an arthropod biocide,naphthalene has been used in studies of the ecological functions of soil fauna for decades.However,its potential non-target effects on soil microorganisms may affect soil mineralization and lit...As an arthropod biocide,naphthalene has been used in studies of the ecological functions of soil fauna for decades.However,its potential non-target effects on soil microorganisms may affect soil mineralization and litter decomposition processes.Therefore,we conducted an experiment with naphthalene adding to soil surface at a rate of 100 g·m-2 per month to examine the potential non-target effects of this treatment on soil fungal phospholipid fatty acids(PLFAs),18 S rDNA gene copy numbers and community diversity in a subalpine forest of western Sichuan,China.The results showed that naphthalene addition significantly increased fungal PLFAs but did not significantly alter fungal gene copy numbers.A total of 16 phyla,62 genera and 147 Operational taxonomic units(OTUs)were identified through Illumina Mi Seq sequencing analysis.Basidiomycota and Ascomycota were the most abundant phyla in both the control and naphthalene addition plots.Naphthalene addition did not affect the diversity or structure of the soil fungal community,but the increase in some genera of Basidiomycota might contribute to the increase in fungal PLFAs in the naphthalene addition plots.These results suggest that naphthalene exerts non-target effects on the active fungal abundance by stimulating the abundance of specific taxa in subalpine forest soils.The non-target effects of naphthalene on the fungal community should be taken into consideration when it is used to exclude soil fauna.展开更多
During a survey of soil fungi in Yunnan Province,several isolates of Aspergillus were obtained.Based on morphology and molecular analyses of internal transcribed spacer regions and intervening 5.8S nrRNA gene(ITS),β-...During a survey of soil fungi in Yunnan Province,several isolates of Aspergillus were obtained.Based on morphology and molecular analyses of internal transcribed spacer regions and intervening 5.8S nrRNA gene(ITS),β-tubulin and calmodulin(CaM)genes sequences,two isolates were identified as Aspergillus vadensis(section Nigri).A phylogenetic tree,detailed descriptions,illustrations and scanned electron microscopy morphology are provided for the new isolates.This is the first record of A.vadensis from China.展开更多
A total of 47 isolates of soil dematiaceous hyphomycetes belonging to 29 species in 15 genera were found from the gorge regions of three rivers (the Jinsha River, the Nu River and the Lantsang River) in eastern Tibet....A total of 47 isolates of soil dematiaceous hyphomycetes belonging to 29 species in 15 genera were found from the gorge regions of three rivers (the Jinsha River, the Nu River and the Lantsang River) in eastern Tibet. Most of the genera and species found are new for the regions. Among them Eladia tibetensis is a new species, and Scytalidium acidophilum and S. circinatum are new records to China. Latin description is given for the new species. Brief descriptions and illustrations of the new records are also given based on Chinese isolates. The other 26 species being previously known from China in several genera are also listed. Dried cultures and living cultures studied have been deposited in Herbarium of Shandong Agricultural University: Plant Pathology (HSAUP).展开更多
In the context of climate change, precipitation is predicted to become more intense at the global scale. Such change may alter soil microbial communities and the microbially mediated carbon and nitrogen dynamics. In t...In the context of climate change, precipitation is predicted to become more intense at the global scale. Such change may alter soil microbial communities and the microbially mediated carbon and nitrogen dynamics. In this study, we experimentally repackaged precipitation patterns during the growing season(from June to September) of 2012 in a semi-arid temperate steppe of the Xilin River Basin in Inner Mongolia of China, based on the 60-year growing season precipitation data. Specifically, a total amount of 240 mm simulated precipitation was assigned to experimental plots by taking the following treatments:(1) P6(6 extreme precipitation events, near the 1^(st) percentile);(2) P10(10 extreme precipitation events, near the 5^(th) percentile);(3) P16(16 moderate precipitation events, near the 50^(th) percentile); and(4) P24(24 events, 60-year average precipitation, near the 50^(th) percentile). At the end of the growing season, we analyzed soil microbial community structure and biomass, bacterial abundance, fungal abundance and bacterial composition, by using phospholipid fatty acid(PLFA), real-time quantitative polymerase chain reaction(RT-qPCR) and 16S rRNA gene clone library methods. The extreme precipitation events did not change soil microbial community structure(represented by the ratio of PLFA concentration in fungi to PLFA concentration in bacteria, and the ratio of PLFA concentration in gram-positive bacterial biomass to PLFA concentration in gram-negative bacterial biomass). However, the extreme precipitation events significantly increased soil microbial activity(represented by soil microbial biomass nitrogen and soil bacterial 16S rRNA gene copy numbers). Soil fungal community showed no significant response to precipitation events. According to the redundancy analysis, both soil microbial biomass nitrogen and soil ammonium nitrogen(NH_4-N) were found to be significant in shaping soil microbial community. Acidobacteria, Actinobacteria and Proteobacteria were the dominant phyla in soil bacterial composition, and responded differently to the extreme precipitation events. Based on the results, we concluded that the extreme precipitation events altered the overall soil microbial activity, but did not impact how the processes would occur, since soil microbial community structure remained unchanged.展开更多
A total of 103 isolates of soil dematiaceous hyphomycetes belonging to 27 species in 15 genera were obtained from soil samples of Mount Taibai and its surrounding area, Shaanxi Province, China. Among them Eladia pachy...A total of 103 isolates of soil dematiaceous hyphomycetes belonging to 27 species in 15 genera were obtained from soil samples of Mount Taibai and its surrounding area, Shaanxi Province, China. Among them Eladia pachyphialis and Gliomastix pallescens are new species, while Acremoniula sarcinellae, Allescheriella crocea, Chrysosporium merdarium, Chrysosporium pannorum are new records to China. The main distinction between E. pachyphialis and its similar species E. saccula is that the phialide of the former is wider and the conidia are smaller than those of the latter. Gliomastix pallescens is characterized by having light colored, long and unbranched conidiophores by which it can be separated from its similar species, G. cerealis. Latin descriptions are given for the new species. Brief descriptions and illustrations of the new records are also provided based on Chinese isolates. The other 21 species being previously known from China in several genera are also listed. All specimens (dried cultures and slides) and living cultures studied have been deposited in the Herbarium of Shandong Agricultural University: Plant Pathology (HSAUP).展开更多
A total of 50 isolates of soil dematiaceous hyphomycetes belonging to 39 species in 18 genera were found from the area of Dahingganling Mountain Range. Among them, Monodictys arxanensis is a new species. Chrysosporium...A total of 50 isolates of soil dematiaceous hyphomycetes belonging to 39 species in 18 genera were found from the area of Dahingganling Mountain Range. Among them, Monodictys arxanensis is a new species. Chrysosporium fastidium, Exserohilum pedicellatum, Monodictys asperospora, Papulaspora brachiata, Scolecobasidium anelli, Scolecobasidium verruculosum and Ulocladium tuberculatum are new to China. The other 31 taxa which have been previously reported from China are also listed. Specimens (dried cultures) and living cultures of all fungi studied have been deposited in the Herbarium of Shandong Agricultural University: Plant Pathology (HSAUP).展开更多
A total of 66 isolates of soil dematiaceous hyphomycetes belonging to 28 species in 22 genera was found from 22 soil samples in tropical primordial rain forest of Jianfengling in Hainan Island. Among them, the genera ...A total of 66 isolates of soil dematiaceous hyphomycetes belonging to 28 species in 22 genera was found from 22 soil samples in tropical primordial rain forest of Jianfengling in Hainan Island. Among them, the genera Beltraniopsis, Domingoella and Phaeoisaria are recorded for the first time in China, while Acrophialophora fusispora, Beltraniopsis esenbeckiae, Domingoella asterinarum, Phaeoisaria clematidis and Stachybotrys nephrospora are new record species to China. Descriptions and illustrations are given based on Chinese isolates. Dried cultures and living cultures studied have been deposited in Herbarium of Shandong Agricultural University: Plant Pathology (HSAUP).展开更多
Biochar is a potential micro-environment for soil microorganisms but evidence to support this suggestion is limited. We explored imaging techniques to visualize and quantify fungal colonization of habitable spaces in ...Biochar is a potential micro-environment for soil microorganisms but evidence to support this suggestion is limited. We explored imaging techniques to visualize and quantify fungal colonization of habitable spaces in a biochar made from a woody feedstock. In addition to characterization of the biochar, it was necessary to optimize preparation and observation methodologies for examining fungal colonization of the biochar. Biochar surfaces and pores were investigated using several microscopy techniques. Biochar particles were compared in soilless media and after deposition in soil. Scanning electron microscopy (SEM) observations and characterization of the biochar demonstrated structural heterogeneity within and among biochar particles. Fungal colonization in and on biochar particles was observed using light, fluorescence and electron microscopy. Fluorescent brightener RR 2200 was more effective than Calcofluor White as a hyphal stain. Biochar retrieved from soil and observed using fluorescence microscopy exhibited distinct hyphal networks on external biochar surfaces. The extent of hyphal colonization of biochar incubated in soil was much less than for biochar artificially inoculated with fungi in a soilless medium. The location of fungal hyphae was more clearly visible using SEM than with fluorescence microscopy. Observations of biochar particles colonized by hyphae from soil posed a range of difficulties including obstruction by the presence of soil particles on biochar surfaces and inside pores. Extensive hyphal colonization of the surface of the biochar in the soilless medium contrasted with limited hyphal colonization of pores within the biochar. Both visualization and quantification of hyphal colonization of surfaces and pores of biochar were restricted by two-dimensional imaging associated with uneven biochar surfaces and variable biochar pore structure. There was very little colonization ofbiochar from hyphae in the agricultural soil used in this study.展开更多
A pot experiment was conducted to study the effects of arbuscular mycorrhizal (AM) fungi (from contaminated or uncontaminated soils) on arsenic (As) uptake of tobacco (Nicotiana tabacurn L.) in As-contaminated...A pot experiment was conducted to study the effects of arbuscular mycorrhizal (AM) fungi (from contaminated or uncontaminated soils) on arsenic (As) uptake of tobacco (Nicotiana tabacurn L.) in As-contaminated soil. Mycorrhizal colonization rate, dry weight, As and P uptake by plants, concentrations of water-extractable As and As fractions were determined. A low mycorrhizal colonization rate (〈 25%) was detected. Our research indicated that AM fungi isolated from polluted soils were no more effective than those from unpolluted soils when grown in symbiosis with tobacco. No significant differences were observed in roots and stalks dry weights among all treatments. Leaves and total plant dry weights were much higher in Glomus versiforme treatment than that in control treatment. As contents in roots and stalks from mycorrhizal treatments were much lower than that from control treatment. Total plant As content exhibited the same trend. P concentrations in tobacco were not affected by colonization, nor were stalks, leaves and total plant P contents. Roots P contents were remarkably lower in HN treatments than in other treatments. Meanwhile, decreased soil pH and lower water-extractable As concentrations and higher levels of As fraction bound to well-crystallized hydrous oxides of Fe and AI were found in mycorrhizal treatments than in controls. The protective effect of mycorrhiza against plant As uptake may be associated with changes in As solubility mediated by changing soil pH. These results indicated that under As stress, proper mechanisms employed by AM fungi can protect tobacco against As uptake. Results confirmed that AM fungi can play an important role in food quality and safety.展开更多
Studies were conducted to identify candidate soil microbes responsible for observed differences in strawberry vigour at a small spatial scale, which was not associated with visual disease symptoms. Samples were obtain...Studies were conducted to identify candidate soil microbes responsible for observed differences in strawberry vigour at a small spatial scale, which was not associated with visual disease symptoms. Samples were obtained from the soils close to the rhizosphere of ‘big' and ‘small' plants from small plots which exhibited large local heterogeneity in plant vigour. A metabarcoding approach was used to profile bacterial and fungal compositions, using two primer pairs for 16 S ribosomal RNA genes(16S r DNA) and one for the fungal internal transcribed spacer(ITS) region. Of the two 16 S r DNA primer sets, the 341F/805 R resulted in sequences of better quality. A total 28 operational taxonomic units(OTUs) had differential relative abundance between samples from ‘big' and ‘small' plants. However, plausible biological explanation was only possible for three fungal OTUs. Two were possible phytopathogens: Verticillium spp. and Alternaria alternata although the latter has never been considered as a main pathogen of strawberry in the UK. For samples from ‘small' plants, the abundance of these OTUs was much greater than from ‘big' plants. The opposite was true for a mycorrhizal OTU. These results suggest that soil microbes related to crop production can be identified using metabarcoding technique. Further research is needed to assess whether A. alternata and Verticillium spp. could affect strawberry growth in the field.展开更多
文摘This study is aimed at identifying and determining the percentage of occurrence frequency of cellulose decomposing soil fungi. The soil samples were inoculated into culture plates prepared in Sabouraud medium under sterilized conditions and incubated at 30 ℃ for 4 to 7 d. The identified fungal species were incubated in self-designed cellulose medium for testing their cellulolytic ability. Forty-two species, including2 nova species, representing sixteen genera showed growth and sporulation in the cellulose medium. Most of the isolated species were from genus Aspergillus and Penicillium. Aspergillus niger and Mucor hiemalis showed highest occurrence frequency (45% and 36% respectively), as these species were collected from about 80% of soil samples. Being agar free and cheaper, the new fungal medium designed showed results equivalent to Sabouraud medium.
文摘Abstract: We assessed soil fungal diversity in the dry deciduous forest ofa Bhadra Wildlife Sanctuary of the Western Ghats (210.31 m a.s.1.; N 13044' and E75°37′). Soil samples were collected by random mixed sampling during winter (November, 2008), summer (March, 2009) and monsoon (August, 2009) seasons, and physico-chemical parameters were recorded. During winter, summer, and monsoon seasons, 49, 45 and 49 of fungal species belongs to 20, 18 and 19 of genera were isolated, respectively. Isolated soil fungi were mainly of the Mitosporic fungi, followed by Zygomycotina, Ascomycotina, Oomycotina and Coelomycetes. Indices of diversity, dominance and fisher alpha during winter, summer and monsoon seasons were 3.756, 3.638 and 3.738 (H), 0.9737, 0.9694 and 0.9726 (I-D) and 18.84, 29.83 and 19.46 (a), respectively. Spear- man's (r) correlation coefficient of fungal population with physicochemical parameters of soils showed significantly positive and negative correlations (p〈0.01) during winter, summer and monsoon seasons. Physico-chemical soil parameters played an important role in the occurrence, diversity, distribution, and relative abundance of fungal species in the tropical dry deciduous forest soil.
文摘This study aims to investigate the abundance of AMF according to soil properties and altitudes in different cacao plantations of Cameroon. Physico-chemical analyses were made on soil samples collected from three agro-ecological zones. Soil samples were also used to evaluate directly the AMF abundance following the various altitudes and after trapping by sorghum plant. The results showed that soil properties, AMF spore abundances and colonization fluctuated significantly at different altitudes. The most represented texture was sandy loam. The bimodal zone presented a homogeneous texture (sandy loam) in all its localities. Cacao soil chemical characteristics showed that, the highest nitrogen rate (0.47%;p 0.05, Scott-Knott test) was recorded at Melong in a monomodal zone while Tonga in the Western highlands displayed the lowest rate (0.13%). Soil P concentration was significantly high in monomodal zones (Mbanga and Melong). Soil pH level indicated that the soil from Tonga in the Western highlands was neutral (pH = 6.67), and soils of other localities under study were acidic with the lowest (4.75) pH level recorded at Melong in a monomodal zone. In soil samples, the highest spore density (1.03 spores/g soil) was observed at Ntui in Bimodal zone, while the lowest spore density (0.26 spores/g soil) was observed at Bafang in the Western highlands. Root colonization showed that the sample from Bokito in a bimodal zone displayed the best frequency of mycorrhization (86.11%) while the sample from Bafang in the Western highlands recorded the lowest (27.11%). The PCA analysis highlighted that available phosphorus, pH and altitude all strongly correlated with AMF root colonization ability and can be used as a predictor of AMF colonization ability in cacao rhizosphere.
基金Supported by National Natural Science Foundation of China (30571264)Nation Key Technology Program (2006BAD07B03)
文摘In order to optimize polymerase chain reaction(PCR) amplification of the internal transcribed spacer(ITS) rDNA region from fungi found in black soil in North China,an orthogonal experimental design [L16(45)] was used to evaluate five factors(template,Mg2+,dNTP,Taq DNA polymerase,and primer) from four levels.Subsequently,the optimal annealing temperature,annealing time,extension time and cycle numbers were evaluated.The results showed that the optimized PCR solution for amplification of ITS region comprised 5 μL 10× buffer,30 ng soil DNA template,3.0 mmol·L-1 Mg2+,0.2 mmol·L-1 dNTPs,0.1 μmol·L-1 each forward and reverse primer,and 2.0 U Taq enzyme in 50 μL reaction volume.The optimal thermal cycling protocol consisted of initial melting at 94℃ for 5 min,followed by 35 cycles at 94℃ for 30 s,56℃ for 30 s,72℃ for 90 s,and a final extension of 72℃ for 10 min.
基金funded by the National Natural Science Foundation of China (51574253)the National High Technology Research and Development Program of China (2013AA102904)the Open Research Project of the State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology (Beijing) (SKLCRSM16KFA01)
文摘In semi-arid region of northwestern China, underground mining subsidence often results in decreased vegetation coverage, impoverishment of soil fertility and water stress. In addition, the physical-chemical and biological properties of soil also change, resulting in more susceptible to degradation. In particular, subsidence causes disturbance of the symbioses of plant and microbe that can play a beneficial role in the establishment of vegetation communities in degraded ecosystems. The objective of this study was to evaluate the effects of revegetation with exotic arbuscular mycorrhizal fungi(AMF) inoculum on the chemical and biological properties of soil over time in mining subsidence areas. Soils were sampled at a depth up to 30 cm in the adjacent rhizosphere of Amorpha fruticose Linn. from five reclaimed vegetation communities in northwestern China. In August 2015, a field trial was set up with five historical revegetation experiments established in 2008(7-year), 2011(4-year), 2012(3-year), 2013(2-year) and 2014(1-year), respectively. Each reclamation experiment included two treatments, i.e., revegetation with exotic AMF inoculum(AMF) and non-AMF inoculum(the control). Root mycorrhizal colonization, glomalin-related soil protein(GRSP), soil organic carbon(SOC), soil nutrients, and enzyme activities were also assessed. The results showed that mycorrhizal colonization of inoculated plants increased by 33.3%–163.0% compared to that of non-inoculated plants(P<0.05). Revegetation with exotic AMF inoculum also significantly improved total GRSR(T-GRSP) and easily extracted GRSP(EE-GRSP) concentrations compared to control, besides the T-GRSP in 1-year experiment and the EE-GRSP in 2-year experiment. A significant increase in SOC content was only observed in 7-year AMF reclaimed soils compared to non-AMF reclaimed soils. Soil total N(TN), Olsen phosphorus(P) and available potassium(K) were significantly higher in inoculated soil after 1–7 years of reclamation(except for individual cases), and increased with reclamation time(besides soil Olsen P). The exotic AMF inoculum markedly increased the average soil invertase, catalase, urease and alkaline phosphatase by 23.8%, 21.3%, 18.8% and 8.6%, respectively(P<0.01), compared with the control. Root mycorrhizal colonization was positively correlated with soil parameters(SOC, TN and soil available K) and soil enzyme activities(soil invertase, catalase, urease and alkaline phosphatase) in both AMF and non-AMF reclaimed soils(P<0.05), excluding availableK in non-AMF reclaimed soils. T-GRSP(P<0.01) and EE-GRSP(P<0.05) were significantly correlated with the majority of edaphic factors, except for soil Olsen P. The positive correlation between root mycorrhizal colonization and available K was observed in AMF reclaimed soils, indicating that the AMF reclaimed soil with a high root mycorrhizal colonization could potentially accumulate available K in soils. Our findings concluded that revegetation with exotic AMF inoculum influenced soil nutrient availability and enzyme activities in the semi-arid ecosystem, suggesting that inoculating AMF can be an effective method to improve soil fertility and support restoration of vegetation communities under poor conditions like soil nutrient deficiency and drought.
文摘138 soil samples were collected from various loca-tions in Ladakh, a cold desert in the Himalayan region, India and the samples were screened for the presence of keratinophilic fungi using the hair baiting techniques. 58 isolates were recovered and identified. The cultures were identified based on their macro- and micro-morphological features. A total of six genera and fourteen species were isolated namely Amauroascus kuehnii (0.72%), Aphanoascus keratinophilus (4.34%), Aphanoascus terreus (2.17%), Auxarthron alboluteum (0.72%), Auxarthron conjugatum (0.72%), Chrysosporium articulatum (0.72%), Chrysosporium mephiticum (0.72%), Chrysosporium minutisporosum (2.17%), Chrysosporium siglerae (0.72%), Chrysosporium sp. (1.44%), Chrysosporium tropicum (15.94 %), Chrysosporium submersum (3.62%), Chrysosporium state of Ctenomyces serratus (6.52%) and Geomyces pannorum (1.45%). The present study shows that keratinophilic fungi exist in the cold desert of Ladakh.
文摘Screening was done for the isolation of effective lignin degraders from the forest soil samples, by providing lignin as a carbon source through the enrichment method, which leads to the isolation of 8 effective fungal isolates among 14 isolates. Submerged fermentation was done for the production of ligninolytic enzymes with the effective microorganisms by providing Guiaicol as a carbon source. The assay of laccase, lignin peroxidise activity and specific activity was done after the incubation intervals of 2, 4, 6, 7, 8, 10 and 12 days at 27±2℃ under shake culture condition. Partially purified protein content was estimated by using Lowry's method. Pleurotus sp. and Phanerochaetae chrysosporium are more effective at the 2nd and 7th days of incubation for the production of laccase and lignin peroxidases among the effective isolates.
基金The present work was supported by Foundation of State Key Basic Research and Development Project (G1998051100)
文摘Two compounds were isolated from ethyl acetate extract of the fermentation of fungus 07-11, which obtained from the soil of Yunnan Province. They were identified as N-(4-hydroxy-2-methoxyphenyl) acetamide (1) and ergosta-7,22-diene-3,6-dione (2) respectively on the basis of spectral analyses and physical and chemical identifications. Compound 1 was a new natural product. Compound 2 was firstly isolated from its genus. Spectral data of 1 and complete 1H NMR data of 2 were reported for the first time.
文摘We examined suitability of arbuscular mycorrhizal fungi (AMF) associated with cool-season nonnative forages on reclaimed surface-mined land in southeast Ohio for establishment of native warm-season grasses. The goal of establishing these grasses is to diversify a post-reclamation landscape that is incapable of supporting native forest species. A 16-week glasshouse study compared AMF from a 30-year reclaimed mine soil (WL) with AMF from native Ohio tallgrass prairie soil (CL). Four native grasses were examined from seedling through 16 weeks of growth. Comparisons were made between CL and WL AMF on colonized (+AMF) and non-colonized plants (–AMF) at three levels of soil phosphorus (P). Leaves were counted at 4 week intervals. Shoot and root biomass and percent AMF root colonization were measured at termination. We found no difference between WL and CL AMF. Added soil P did not reduce AMF colonization, but did reduce AMF efficacy. Big bluestem (Andropogon gerardii Vitman), Indiangrass (Sorghastrum nutans (L.) Nash), and tall dropseed (Sporobolus asper (Michx.) Kunth) benefited from AMF only at low soil P while slender wheatgrass (Elymus trachycaulus (Link) Gould ex Shinners) exhibited no benefit. Establishment of tallgrass prairie dominants big blue-stem and Indiangrass would be supported by the mine soil AMF. It appears that the non-native forage species have supported AMF equally functional as AMF from a regionally native tallgrass prairie. Tall dropseed and slender wheatgrass were found to be less dependent on AMF than big bluestem or Indiangrass and thus would be useful in areas with little or no AMF inoculum.
基金funded by the National Key Research and Development Program of China (Grant No.2017 YFC0504003)Inner Mongolia Natural Science Foundation(No.2018MS03049)Young Teacher Research Fund Project of Forestry College of Inner Mongolia Agricultural University。
文摘Fires are an important factor impacting forest ecosystems of Daxing'anling and have a significant effect on soil microbial community structure.In this study,highthroughput sequencing for 16 S rDNA and ITS rDNA were applied to analyze the changing characteristics and driving factors of bacterial and fungal community structures in burned areas with different fire severity.PICRUSt2 software was used to predict the functional characteristics of burned areas with different fire severity.The purpose was to unveil the responsive relationships among the structure and function of bacterial and fungal communities,fire severity,and post-disturbance restoration times.After high severity fires,the destruction of surface vegetation and loss of soil nutrients reduced the diversity and abundance of soil bacteria and fungi.The soil bacteria community structure,which was dominated by Acidobacteria,Proteobacteria,and Actinobacteria,changed to be dominated by Proteobacteria and Chloroflexi.As well,soil fungal community changed from domination by Helotiales,Eurotiales and Russulales to domination by Archaeorhizomycetales and Helotiales.Over time,soil bacterial community was gradually restored to prefire levels 30 years after the fire.Soil fungal community changed and failed to restore to pre-fire levels after 30 years.After low/intermediate severity fires,environmental factors were relatively unchanged so that soil bacteria diversity and abundance increased,optimizing community composition.The diversity and abundance of soil fungi decreased and the community structure changed slightly.Over time,both bacterial and fungal communities were gradually restored to pre-fire levels 30 years after the fire.After fire disturbance,with increasing severity,soil carbon fixation,lignin degradation,mineralization of organic nitrogen and hydrolysis of organic phosphorus are enhanced.Denitrification is weakened.Therefore,forest fires have certain positive effects on carbon,nitrogen and phosphorus cycles where soil bacteria and fungi are involved.
基金funded by the National Natural Science Foundation of China(31870602,31700542 and 31500509)the National Key R&D Program of China(2017YFC0503906)the Special Fund for Key Program of Science and Technology of Sichuan Province(2018SZDZX0030)。
文摘As an arthropod biocide,naphthalene has been used in studies of the ecological functions of soil fauna for decades.However,its potential non-target effects on soil microorganisms may affect soil mineralization and litter decomposition processes.Therefore,we conducted an experiment with naphthalene adding to soil surface at a rate of 100 g·m-2 per month to examine the potential non-target effects of this treatment on soil fungal phospholipid fatty acids(PLFAs),18 S rDNA gene copy numbers and community diversity in a subalpine forest of western Sichuan,China.The results showed that naphthalene addition significantly increased fungal PLFAs but did not significantly alter fungal gene copy numbers.A total of 16 phyla,62 genera and 147 Operational taxonomic units(OTUs)were identified through Illumina Mi Seq sequencing analysis.Basidiomycota and Ascomycota were the most abundant phyla in both the control and naphthalene addition plots.Naphthalene addition did not affect the diversity or structure of the soil fungal community,but the increase in some genera of Basidiomycota might contribute to the increase in fungal PLFAs in the naphthalene addition plots.These results suggest that naphthalene exerts non-target effects on the active fungal abundance by stimulating the abundance of specific taxa in subalpine forest soils.The non-target effects of naphthalene on the fungal community should be taken into consideration when it is used to exclude soil fauna.
基金This research was funded by Key Research Project“Agroforestry Systems for Restoration and Bio-industry Technology Development”,Grant No.2017YFC0505101S.Khan,S.Tibpromma and D.Wanasinghe are thankful to the CAS President’s International Fellowship Initiative(PIFI Grant Nos.2019PC0011,2020PC0009 and 2019PC0008)+2 种基金S.Tibpromma is thankful to the International Postdoctoral Exchange Fellowship Program(No.Y9180822S1)China Postdoctoral Science Foundation,Yunnan Human Resources and Social Security Department Foundation.D.Wanasinghe is thankful to the 64th batch of China Postdoctoral Science Foundation(Grant No.Y913083271)P.Mortimer is thankful to the National Science Foundation of China(NSFC),Project Codes 41761144055 and 41771063.
文摘During a survey of soil fungi in Yunnan Province,several isolates of Aspergillus were obtained.Based on morphology and molecular analyses of internal transcribed spacer regions and intervening 5.8S nrRNA gene(ITS),β-tubulin and calmodulin(CaM)genes sequences,two isolates were identified as Aspergillus vadensis(section Nigri).A phylogenetic tree,detailed descriptions,illustrations and scanned electron microscopy morphology are provided for the new isolates.This is the first record of A.vadensis from China.
基金Supported by the National Natural Science Foundation of China (NSFC) (No. 30670014 & 30499340)
文摘A total of 47 isolates of soil dematiaceous hyphomycetes belonging to 29 species in 15 genera were found from the gorge regions of three rivers (the Jinsha River, the Nu River and the Lantsang River) in eastern Tibet. Most of the genera and species found are new for the regions. Among them Eladia tibetensis is a new species, and Scytalidium acidophilum and S. circinatum are new records to China. Latin description is given for the new species. Brief descriptions and illustrations of the new records are also given based on Chinese isolates. The other 26 species being previously known from China in several genera are also listed. Dried cultures and living cultures studied have been deposited in Herbarium of Shandong Agricultural University: Plant Pathology (HSAUP).
基金financially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA19030202)the International Cooperation and Exchange of National Natural Science Foundation of China (31761123001, 31761143018)
文摘In the context of climate change, precipitation is predicted to become more intense at the global scale. Such change may alter soil microbial communities and the microbially mediated carbon and nitrogen dynamics. In this study, we experimentally repackaged precipitation patterns during the growing season(from June to September) of 2012 in a semi-arid temperate steppe of the Xilin River Basin in Inner Mongolia of China, based on the 60-year growing season precipitation data. Specifically, a total amount of 240 mm simulated precipitation was assigned to experimental plots by taking the following treatments:(1) P6(6 extreme precipitation events, near the 1^(st) percentile);(2) P10(10 extreme precipitation events, near the 5^(th) percentile);(3) P16(16 moderate precipitation events, near the 50^(th) percentile); and(4) P24(24 events, 60-year average precipitation, near the 50^(th) percentile). At the end of the growing season, we analyzed soil microbial community structure and biomass, bacterial abundance, fungal abundance and bacterial composition, by using phospholipid fatty acid(PLFA), real-time quantitative polymerase chain reaction(RT-qPCR) and 16S rRNA gene clone library methods. The extreme precipitation events did not change soil microbial community structure(represented by the ratio of PLFA concentration in fungi to PLFA concentration in bacteria, and the ratio of PLFA concentration in gram-positive bacterial biomass to PLFA concentration in gram-negative bacterial biomass). However, the extreme precipitation events significantly increased soil microbial activity(represented by soil microbial biomass nitrogen and soil bacterial 16S rRNA gene copy numbers). Soil fungal community showed no significant response to precipitation events. According to the redundancy analysis, both soil microbial biomass nitrogen and soil ammonium nitrogen(NH_4-N) were found to be significant in shaping soil microbial community. Acidobacteria, Actinobacteria and Proteobacteria were the dominant phyla in soil bacterial composition, and responded differently to the extreme precipitation events. Based on the results, we concluded that the extreme precipitation events altered the overall soil microbial activity, but did not impact how the processes would occur, since soil microbial community structure remained unchanged.
基金Supported by the National Natural Science Foundation of China (NSFC) (No.30570005 & 30499340)
文摘A total of 103 isolates of soil dematiaceous hyphomycetes belonging to 27 species in 15 genera were obtained from soil samples of Mount Taibai and its surrounding area, Shaanxi Province, China. Among them Eladia pachyphialis and Gliomastix pallescens are new species, while Acremoniula sarcinellae, Allescheriella crocea, Chrysosporium merdarium, Chrysosporium pannorum are new records to China. The main distinction between E. pachyphialis and its similar species E. saccula is that the phialide of the former is wider and the conidia are smaller than those of the latter. Gliomastix pallescens is characterized by having light colored, long and unbranched conidiophores by which it can be separated from its similar species, G. cerealis. Latin descriptions are given for the new species. Brief descriptions and illustrations of the new records are also provided based on Chinese isolates. The other 21 species being previously known from China in several genera are also listed. All specimens (dried cultures and slides) and living cultures studied have been deposited in the Herbarium of Shandong Agricultural University: Plant Pathology (HSAUP).
基金Supported by the National Natural Science Foundation of China (NSFC) (No. 30570012 & 30499340)
文摘A total of 50 isolates of soil dematiaceous hyphomycetes belonging to 39 species in 18 genera were found from the area of Dahingganling Mountain Range. Among them, Monodictys arxanensis is a new species. Chrysosporium fastidium, Exserohilum pedicellatum, Monodictys asperospora, Papulaspora brachiata, Scolecobasidium anelli, Scolecobasidium verruculosum and Ulocladium tuberculatum are new to China. The other 31 taxa which have been previously reported from China are also listed. Specimens (dried cultures) and living cultures of all fungi studied have been deposited in the Herbarium of Shandong Agricultural University: Plant Pathology (HSAUP).
基金Supported by the National Natural Science Foundation of China (NSFC) (No. 30570005 & 30499340)
文摘A total of 66 isolates of soil dematiaceous hyphomycetes belonging to 28 species in 22 genera was found from 22 soil samples in tropical primordial rain forest of Jianfengling in Hainan Island. Among them, the genera Beltraniopsis, Domingoella and Phaeoisaria are recorded for the first time in China, while Acrophialophora fusispora, Beltraniopsis esenbeckiae, Domingoella asterinarum, Phaeoisaria clematidis and Stachybotrys nephrospora are new record species to China. Descriptions and illustrations are given based on Chinese isolates. Dried cultures and living cultures studied have been deposited in Herbarium of Shandong Agricultural University: Plant Pathology (HSAUP).
文摘Biochar is a potential micro-environment for soil microorganisms but evidence to support this suggestion is limited. We explored imaging techniques to visualize and quantify fungal colonization of habitable spaces in a biochar made from a woody feedstock. In addition to characterization of the biochar, it was necessary to optimize preparation and observation methodologies for examining fungal colonization of the biochar. Biochar surfaces and pores were investigated using several microscopy techniques. Biochar particles were compared in soilless media and after deposition in soil. Scanning electron microscopy (SEM) observations and characterization of the biochar demonstrated structural heterogeneity within and among biochar particles. Fungal colonization in and on biochar particles was observed using light, fluorescence and electron microscopy. Fluorescent brightener RR 2200 was more effective than Calcofluor White as a hyphal stain. Biochar retrieved from soil and observed using fluorescence microscopy exhibited distinct hyphal networks on external biochar surfaces. The extent of hyphal colonization of biochar incubated in soil was much less than for biochar artificially inoculated with fungi in a soilless medium. The location of fungal hyphae was more clearly visible using SEM than with fluorescence microscopy. Observations of biochar particles colonized by hyphae from soil posed a range of difficulties including obstruction by the presence of soil particles on biochar surfaces and inside pores. Extensive hyphal colonization of the surface of the biochar in the soilless medium contrasted with limited hyphal colonization of pores within the biochar. Both visualization and quantification of hyphal colonization of surfaces and pores of biochar were restricted by two-dimensional imaging associated with uneven biochar surfaces and variable biochar pore structure. There was very little colonization ofbiochar from hyphae in the agricultural soil used in this study.
基金supported by the Innovative Research International Partnership Project of Chinese Academy of Science (No.CXTD-Z2005-4)
文摘A pot experiment was conducted to study the effects of arbuscular mycorrhizal (AM) fungi (from contaminated or uncontaminated soils) on arsenic (As) uptake of tobacco (Nicotiana tabacurn L.) in As-contaminated soil. Mycorrhizal colonization rate, dry weight, As and P uptake by plants, concentrations of water-extractable As and As fractions were determined. A low mycorrhizal colonization rate (〈 25%) was detected. Our research indicated that AM fungi isolated from polluted soils were no more effective than those from unpolluted soils when grown in symbiosis with tobacco. No significant differences were observed in roots and stalks dry weights among all treatments. Leaves and total plant dry weights were much higher in Glomus versiforme treatment than that in control treatment. As contents in roots and stalks from mycorrhizal treatments were much lower than that from control treatment. Total plant As content exhibited the same trend. P concentrations in tobacco were not affected by colonization, nor were stalks, leaves and total plant P contents. Roots P contents were remarkably lower in HN treatments than in other treatments. Meanwhile, decreased soil pH and lower water-extractable As concentrations and higher levels of As fraction bound to well-crystallized hydrous oxides of Fe and AI were found in mycorrhizal treatments than in controls. The protective effect of mycorrhiza against plant As uptake may be associated with changes in As solubility mediated by changing soil pH. These results indicated that under As stress, proper mechanisms employed by AM fungi can protect tobacco against As uptake. Results confirmed that AM fungi can play an important role in food quality and safety.
基金funded by Innovate UK(100867)with matching funding from several commercial companiesthe financial assistance of the China Scholarship Council(201306300133 and 201506300012)
文摘Studies were conducted to identify candidate soil microbes responsible for observed differences in strawberry vigour at a small spatial scale, which was not associated with visual disease symptoms. Samples were obtained from the soils close to the rhizosphere of ‘big' and ‘small' plants from small plots which exhibited large local heterogeneity in plant vigour. A metabarcoding approach was used to profile bacterial and fungal compositions, using two primer pairs for 16 S ribosomal RNA genes(16S r DNA) and one for the fungal internal transcribed spacer(ITS) region. Of the two 16 S r DNA primer sets, the 341F/805 R resulted in sequences of better quality. A total 28 operational taxonomic units(OTUs) had differential relative abundance between samples from ‘big' and ‘small' plants. However, plausible biological explanation was only possible for three fungal OTUs. Two were possible phytopathogens: Verticillium spp. and Alternaria alternata although the latter has never been considered as a main pathogen of strawberry in the UK. For samples from ‘small' plants, the abundance of these OTUs was much greater than from ‘big' plants. The opposite was true for a mycorrhizal OTU. These results suggest that soil microbes related to crop production can be identified using metabarcoding technique. Further research is needed to assess whether A. alternata and Verticillium spp. could affect strawberry growth in the field.