The objective of this work was to carry out a morphological characterization of arbuscular mycorrhizal fungi in the rhizosphere of Xanthosoma sagittifolium L. Schott plants. The plant material used was the white and r...The objective of this work was to carry out a morphological characterization of arbuscular mycorrhizal fungi in the rhizosphere of Xanthosoma sagittifolium L. Schott plants. The plant material used was the white and red cultivars of X. sagittifolium, belonging to age intervals of 3 - 6, 6 - 9, and 9 - 12 months. Three harvest sites were chosen in the Central Region of Cameroon. In each site, soil from the rhizosphere and plant roots was collected in a randomized manner. In the field, the agronomic parameters were evaluated. The physicochemical characteristics of the soils, the mycorrhization index, and the morphological characterization of the mycorrhizal types of each site were carried out. The results obtained show that the agronomic growth parameters varied significantly using the Student Newman and Keuls Test depending on the harvest sites. The soils’ pH in all sites was acidic and ranged between 4.6 and 5.8. The Nkometou site has a loamy texture while the Olembe and Soa sites have loam-clay-sandy and loam-clay textures respectively. The highest mycorrhization frequencies appeared at the Nkometou site, with 75 and 87.33% of the white and red cultivars plant roots at 6 - 9 and 3 - 6 months. The relative abundance of AMF arbuscular mycorrhizal fungal spores in the rhizosphere of X. sagittifolium plants varied with age and cultivar. There were 673 spores between 9 - 12 months in Nkometou in the red cultivar. Six AMF genera were identified in all the different soils collected: Acaulospora sp., Funneliformis sp., Gigaspora sp., Glomus sp., Scutellospora sp., and Septoglomus sp. The genus Glomus sp. was the most present at all age intervals in both cultivars.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
Alternate wetting and drying(AWD)system,in which water has been reduced by approximately 35%with an increased occurrence of beneficial arbuscular mycorrhizal(AM)symbiosis and no negative impact on rice yield,was propo...Alternate wetting and drying(AWD)system,in which water has been reduced by approximately 35%with an increased occurrence of beneficial arbuscular mycorrhizal(AM)symbiosis and no negative impact on rice yield,was proposed to utilize water and nutrients more sustainable.In this study,we selected six rice cultivars(Centauro,Loto,Selenio,Vialone nano,JSendra and Puntal)grown under AWD conditions,and investigated their responsiveness to AM colonization and how they select diverse AM taxa.In order to investigate root-associated AM fungus communities,molecular cloning-Sanger sequencing on small subunit rDNA data were obtained from five out of the six rice cultivars and compared with Next Generation Sequencing(NGS)data,which were previously obtained in Vialone nano.The results showed that all the cultivars were responsive to AM colonization with the development of AM symbiotic structures,even if with differences in the colonization and arbuscule abundance in the root systems.We identified 16 virtual taxa(VT)in the soil compartment and 7 VT in the root apparatus.We emphasized that the NGS analysis gives additional value to the results thanks to a more in-depth reading of the less represented AM fungus taxa.展开更多
Arbuscular mycorrhizal fungi(AMF)are important members of the plant microbiome and affect the uptake and transfer of mineral elements by forming a symbiotic relationship with plant roots.Nitrogen(N),as an important mi...Arbuscular mycorrhizal fungi(AMF)are important members of the plant microbiome and affect the uptake and transfer of mineral elements by forming a symbiotic relationship with plant roots.Nitrogen(N),as an important mineral element,can directly affect plant growth and development at different N levels.It has been confirmed that inoculation with AMF can improve the efficiency of N utilization by plants.However,there are still fewer reports on the dynamic relationship between arbuscular mycorrhizal and plant secondary metabolites at different nitrogen levels.In this experiment,the physiological indexes and genes related to saponin synthesis were determined by applying different concentration gradients of nitrogen to the medicinal plant P.polyphylla var.yunnanensis infested by AMF as the test material.It was found that nitrogen addition increased the biomass,chlorophyll content,and nutrient content of above-and below-ground plant parts and increased the content of saponin content of P.polyphylla var.yunnanensis to some extent,but AMF inoculation increased the saponin content of P.polyphylla var.yunnanensis more significantly.AMF inoculation also promoted the expression of genes related to the saponin synthesis pathway,including 3-hydroxy-3-methylglutaryl coenzyme A synthase(HMGS),squalene epoxidase 1(SE1),and cycloartenol synthase(CAS),which is in according with the accumulation of saponin in plants.It also may increase the saponin content of AMF plants by altering the expression of P450s and UGTs related to saponin synthesis.展开更多
The species richness and propagule number of arbuscular mycorrhizal fungi(AMF)are high in intensively-managed agricultural soils.Past research has shown that AMF improve crop phosphorus(P)uptake under low soil P condi...The species richness and propagule number of arbuscular mycorrhizal fungi(AMF)are high in intensively-managed agricultural soils.Past research has shown that AMF improve crop phosphorus(P)uptake under low soil P conditions,however it is unclear if AMF play a role in high Olsen-P soils.In this study,we investigated whether native fungal benefits exist under high P input field conditions in-situ and contribute to P utilization.We installed in-grow tubes which were sealed with different membrane pore sizes(30 or 0.45μm)to allow or prevent AMF hyphae access to the hyphal compartment and prevent cotton roots from penetrating the chamber.We used the depletion of soil available P(Olsen-P)in the hyphae accessed compartment to indicate P uptake by the native AMF community.Our results showed that the native AMF mediated P depletion and microbial biomass P(MBP)turnover and caused the largest Olsen-P depletion ratio and MBP turnover ratio in the high P treatments(Olsen-P:78.29 mg kg^(-1)).The cotton roots in each fertilization regime were colonized by a unique AMF community and Glomus and Paraglomus were the dominant genera,implying the longterm fertilization regimes domesticated the AMF community.We conclude that native AMF caused the P depletion and P turnover even under high soil Olsen-P conditions.展开更多
Hevea brasiliensis is one of the important economic trees with a great economic value for natural rubber production.Symbiosis between roots of H.brasiliensis and arbuscular mycorrhizal fungi(AMF)is widely recognized,a...Hevea brasiliensis is one of the important economic trees with a great economic value for natural rubber production.Symbiosis between roots of H.brasiliensis and arbuscular mycorrhizal fungi(AMF)is widely recognized,and can provide a range of benefits for both of them.Hainan Island harbors is one of the largest plantations of H.brasiliensis in China,whereas the information regarding the diversity of AMF in the rhizosphere of H.brasiliensis on this island is scarce.The diversity of AMF species in the rhizosphere of rubber tree plantations in Hainan was investigated in this study.A total of 72 soil samples from the rhizosphere of H.brasiliensis RY7-33-97 were collected.These included 48 samples from plantations in 11 cities or counties that had been planted for 15–25 years,and 24 samples from a demonstrating plantation site of the China National Rubber Tree Germplasm Repository representing plantations with tree plantation ages from one to 40 year-old.Collectively,a total of 68 morphotypes of AMF,belonging to the genera of Archaeospora(1),Glomus(43),Acaulospora(18),Entrophospora(3),Scutellospora(2),and Gigaspora(1)were isolated and identified,as per morphological characteristics of spores presented in the collected soil samples.Glomus(Frequency,F=100%)and Acaulospora(F=100%)were the predominant genera,and A.mellea(F=63.9%)and A.scrobiculata(F=63.9%)were the predominant species.AMF species differed significantly among collected sites in spore density(SD,290.7–2,186.7 spores per 100 g dry soil),species richness(SR,4.3–12.3),and Shannon-Weiner index of diversity(H,1.24–2.24).SD was negatively correlated with available phosphorus level in the soil;SR was positively correlated with soil total phosphorus content;and H was positively correlated with levels of soil organic matter and total phosphorus.Similarly,SD,SR,and H were also correlated with H.brasiliensis plantation age,and an increasing trend was observed up to 40 years.These results suggest that the AMF community was complex and ubiquitous in the island plantation ecosystems of H.brasiliensis,with high species abundance and diversity.Soil factors and plantation age dramatically affected AMF diversity at species level.展开更多
[Objective] This study aimed to investigate the effects of 5 kinds of arbuscular mycorrhizal fungi( Acaulospora mellea,Glomus mosseae,Glomus versiforme,Glomus aggregatum,Glomus etunicatum) on the growth and protective...[Objective] This study aimed to investigate the effects of 5 kinds of arbuscular mycorrhizal fungi( Acaulospora mellea,Glomus mosseae,Glomus versiforme,Glomus aggregatum,Glomus etunicatum) on the growth and protective enzyme activity of Glycyrrhiza uralensis Fisch. [Method] The growth indicators and protective enzymes activity of glycyrrhiza plants inoculated and uninoculated with fungi were compared. [Result] The plant height,basal diameter,main root length,aboveground fresh weight,underground fresh weight,aboveground dry weight and underground dry weight of the inoculated glycyrrhiza plants were increased significantly compared with those in the control( non-inoculation) group. In the inoculated glycyrrhiza plants,the growth index was significantly increased compared with that in the control group( P <0. 05); the activities of superoxide dismutase( SOD) and peroxidase( POD) increased first and then decreased; and the activity of catalase( CAT) showed a continuous rising trend. The effects of different inoculants on the growth of G. uralensis were significantly different.[Conclusion]G. etunicatum,G. mosseae and G. aggregatum had a significant effect on the growth of G. uralensis,and were superior to other fungi in resisting the adverse environment.展开更多
We investigated the arbuscular mycorrhizal fungi(AMF)status of ten nurseries suitable for restoration of dry evergreen Afromontane forests in Ethiopia.We quantified AMF root colonization(RC)and spore abundance(SA)in s...We investigated the arbuscular mycorrhizal fungi(AMF)status of ten nurseries suitable for restoration of dry evergreen Afromontane forests in Ethiopia.We quantified AMF root colonization(RC)and spore abundance(SA)in seedlings of nine native tree species namely Acacia abyssinica Hochst.ex Benth.,Cordia africana Lam.,Dovyalis abyssinica(A.Rich.)Warb.,H agenia abyssinica J.F.Gmel.,Juniperus procera Hochst.ex Endl.,Millettia ferruginea(Hochst.)Baker,Olea europaea L.subsp.c uspidata(Wall.ex G.Don)Cif.,Podocarpus falcatus(Thunb.)R.Br.ex Mirb.and Prunus africana(Hook.f.)Kalkman.We used the ink and vinegar method to stain AMF in roots.RC levels ranged from 8.00 to 99.67%and were generally higher than the RC levels reported from other similar nurseries in Ethiopia.SA levels ranged from 1 to 25 spores g~(-1)and werecomparable with some reports from the field in Ethiopia but they were lower than levels reported by another similar study.RC was more affected by host species than nursery location,while the reverse was true for SA.The results also showed that nursery management could improve AMF status among seedlings.When all nursery tree species were considered,RC and SA levels were unrelated.No strong correlation existed between the nursery management variables considered and RC or SA.However,considering C.africana,J.procera and P.falcatus separately,RC-age(r_(s)=0.829,P=0.042)correlation for O.europaea and RC-pot diameter(r_(s)=0.820,P=0.046),RC-pot volume(r_(s)=0.928,P=0.008)and SA-age(r_(s)=0.943,P=0.005)correlations for C.africana,were significant,strong and positive.Generally,most of the tree species and particularly,early-mid successional tree species had sufficient AMF inoculum.Hence,only the mid-late successional tree species;J.procera,P.falcatus,and P.africana may require AMF inoculation,preferably,during filed planting.Based on our results,age and pot volume were identified to be important variables potentially affecting RC and SA.To better understand the effects of these and other nursery management variables,additional study is required.We demonstrated for the first time that black Hero ink is suitable for staining root AMF and can be used in future AMF research.展开更多
The rising claim for more environmental friendly and healthy agriculture is a strong incentive to find alternative strategies to replace the use of mineral fertilizer and pesticide. Arbuscular mycorrhizal fungi (AMF),...The rising claim for more environmental friendly and healthy agriculture is a strong incentive to find alternative strategies to replace the use of mineral fertilizer and pesticide. Arbuscular mycorrhizal fungi (AMF), a main component of soil microbiota, represent a promising tool as providers of key ecological services. The present work represented one of the first attempts to study, under a morphological and molecular point of view, the AMF communities associated to some strategic crops in Vietnam. The findings about the AMF morphotypes dominant in different crop systems could be a starting point for the development of well performing and adapted inocula suitable for the application in field.展开更多
The objective of this research was to improve the growth and biomass of Pterocarpus santalinus L.f.(an endangered leguminous tree)using native microbial symbionts such as arbuscular mycorrhizal fungi and Rhizobium ass...The objective of this research was to improve the growth and biomass of Pterocarpus santalinus L.f.(an endangered leguminous tree)using native microbial symbionts such as arbuscular mycorrhizal fungi and Rhizobium associated with native populations of P.santalinus.The native arbuscular mycorrhizal fungi isolated from P.santalinus soils were identifi ed as(1)Glomus fasciculatum;(2)Glomus geosporum;and Glomus aggregatum.A nitrogenfi xing microbial symbiont was isolated from the root nodules of P.santalinus and identifi ed as Rhizobium aegyptiacum by 16s rRNA gene sequencing.These microbial symbionts were inoculated individually and in combination into P.santalinus seedling roots.After 90 days,growth and biomass had improved compared with uninoculated controls.Shoot and root lengths,number of leaves,stem circumference,number of root nodules,biomass,nutrient uptake and seedling quality index were signifi cantly increased by a combined inoculation of arbuscular mycorrhizal fungi+Rhizobium aegyptiacum.It was concluded that native microbial symbionts positively infl uenced P.santalinus seedling growth which will be helpful for successful fi eld establishment.展开更多
Nitraria tangutorum Bobr.,a typical xero-halophyte,can be used for vegetation restoration and reconstruction in arid and semiarid regions affected by salinity.However,global climate change and unreasonable human activ...Nitraria tangutorum Bobr.,a typical xero-halophyte,can be used for vegetation restoration and reconstruction in arid and semiarid regions affected by salinity.However,global climate change and unreasonable human activity have exacerbated salinization in arid and semi-arid regions,which in turn has led to the growth inhibition of halophytes,including N.tangutorum.Arbuscular mycorrhizal fungi(AMF)and plant growth-promoting rhizobacteria(PGPR)have the potential to improve the salt tolerance of plants and their adaptation to saline soil environments.In this study,the effects of single and combined inoculations of AMF(Glomus mosseae)and PGPR(Bacillus amyloliquefaciens FZB42)on N.tangutorum were evaluated in severe saline soil conditions.The results indicate that AMF and PGPR alone may not adapt well to the real soil environment,and cannot ensure the effect of either growth promotion or salt-tolerance induction on N.tangutorum seedlings.However,the combination of AMF and PGPR significantly promoted mycorrhizal colonization,increased biomass accumulation,improved morphological development,enhanced photosynthetic performance,stomatal adjustment ability,and the exchange of water and gas.Co-inoculation also significantly counteracted the adverse effect of salinity on the soil structure of N.tangutorum seedlings.It is concluded that the effectiveness of microbial inoculation on the salt tolerance of N.tangutorum seedlings depends on the functional compatibility between plants and microorganisms as well as the specific combinations of AMF and PGPR.展开更多
The effects of biochar(BC),arbuscular mycorrhizal fungi(AM),nitrogen(N)and their composite treatments(BC+N,AM+N,BC+AM and BC+AM+N)application on Cichorium intybus L.(C.intybus L.)nutrient uptake,soil properties and ca...The effects of biochar(BC),arbuscular mycorrhizal fungi(AM),nitrogen(N)and their composite treatments(BC+N,AM+N,BC+AM and BC+AM+N)application on Cichorium intybus L.(C.intybus L.)nutrient uptake,soil properties and cadmium(Cd)accumulation were investigated in Cd contaminated soil(0.11 mg·kg^(-1)).The results showed that the addition of BC increased the rate of mycorrhizal infection.However,the addition of N slightly inhibited mycorrhizal colonization,and the shoot and root bioaccumulation of chicory was positively influenced by BC and N when inoculated with AM fungi.Compared with the single component treatment(AM,BC or N)or two-component treatment(BC+N,AM+N or BC+AM),the three-component composite treatment(BC+AM+N)had the highest shoot bioaccumulation,whereas BC+AM treatment was considered the best for root biomass bioaccumulation.Compared with the control treatment,the single component treatment(AM,BC or N)and the composite treatment resulted in an overall improvement of the chicory shoot,root related nutrient uptake(N,P,K,Mg,Ca,Mn and Fe)and some soil physicochemical properties;in addition,these treatments showed better results than BC+AM+N and BC+AM treatments.Among the Cd-related indexes,Cd concentrations in the shoot,root and soil of C.intybus L.were reduced through treatment with AM and BC.However,a lower bioconcentration coefficient(BCF)and a higher transfer coefficient(TF)were observed in both treatments,and the most desirable effect was observed following the combination treatment(BC+AM).Compared with other single management,the shoot and root Cd concentrations of C.intybus L.after the management of N alone were higher,and the value of BCF(2.63%)was higher,but the value of TF(1.05%)was lower.Indexes related to Cd improved concurrently following the application of N in combination with BC or AM.Therefore,in Cd contaminated soils,single or combined application of BC,AM and N could promote chicory growth and nutrient uptake and improve some soil physicochemical properties.However,N should not be applied alone and needed to be combined with AM and BC;furthermore,it was evident that the treatment with the three composites(BC+AM+N)was optimal from an application point of view.展开更多
Salinity is a major problem that seriously impacts agricultural production, particularly that of tomato (Solanum lycopersicum L.). However, the plant has the ability to associate with Arbuscular Mycorrhizal Fungi to b...Salinity is a major problem that seriously impacts agricultural production, particularly that of tomato (Solanum lycopersicum L.). However, the plant has the ability to associate with Arbuscular Mycorrhizal Fungi to better tolerate salt stress. Thus, thanks to the extension of the AMF hyphae, the hydromineral nutrition and the tolerance to excess toxic ions (Na<sup>+</sup> and Cl<sup>-</sup>) of the plant are optimized. In this context, the contribution of AMF to the salt stress tolerance of two tomato varieties under semi-controlled conditions was studied. To do this, the frequency and intensity of mycorrhization, the relative mycorrhizal dependency, the survival rates, the aerial and root dry weights, the mineral (P, K<sup>+</sup>, Na<sup>+</sup>) and proline contents of the plants subjected to four levels of salinity [0, 70, 140 and 210 mM of NaCl] were evaluated. All the parameters assessed appeared to be dependent on the variety, the fungal strain and the NaCl concentration. With the Lady Nema variety, inoculation with the Claroideoglomus etunicatum strain at [NaCl 140 mM] resulted in the highest frequencies (54%), intensities (40.47%), and relative mycorrhizal dependencies (19.65%). This same symbiotic couple recorded high survival rates (55%) and aerial (2.03 g) and root (0.50 g) dry weights. Significant contents of K<sup>+ </sup>(Leaves: 7.5 mg⋅g<sup>-1</sup>;Roots: 4.4 mg⋅g<sup>-1</sup> of dry matter), P (Leaves: 15.15 mg⋅g-1</sup> of dry matter) and proline (975 nmoles⋅g-1</sup> of fresh matter) were also recorded by this pair, with the lowest Na<sup>+</sup> contents (Leaves: 1.93 mg⋅g-1</sup>;Roots: 0.96 mg⋅g-1</sup> of dry matter). For the Mongal variety, at [NaCl 140 mM], the highest frequencies (50.36%), intensities (35.14%) and relative mycorrhizal dependencies (43.95%) were obtained thanks to inoculation with Rhizophagus fasciculatus. The highest survival rates (59%) and aerial (2.58 g) and root (0.79 g) dry weights were also obtained with this symbiotic couple. The contents of K<sup>+</sup> (Leaves: 6.1 mg⋅g-1</sup>;Roots: 3.09 mg⋅g-1 </sup>of dry matter), P (Leaves: 12.49 mg⋅g-1</sup> of dry matter) and proline (942 nmoles⋅g-1</sup> of fresh matter) the most important and those in Na<sup>+</sup> the lowest (Leaves: 2.03 mg⋅g-1</sup>;Roots: 1.53 mg⋅g-1</sup> of dry matter) were also recorded for this same pair. Thus, the best fungal partner for the Lady Nema variety is C. etunicatum, followed by F. mosseae and R. fasciculatus, while for the Mongal variety it is R. fasciculatus, followed by C. etunicatum and F. mosseae.展开更多
Arbuscular Mycorrhizal Fungi (AMFs) could be used to sustainably improve crop yields. The present study evaluated the diversity of AMF species associated with soybean (Glycine max L. Merill) in main soybean-producing ...Arbuscular Mycorrhizal Fungi (AMFs) could be used to sustainably improve crop yields. The present study evaluated the diversity of AMF species associated with soybean (Glycine max L. Merill) in main soybean-producing areas in Benin. Composite soil samples from 13 production areas at a rate of 04 villages per production areas were collected. A spore trapping device was set up to reveal the diversity of spores. The physical and chemical properties of the soils, the frequency and intensity of mycorrhization of roots, and the diversity of AMF spores were determined in the soil samples following trapping. As result, eight morphotypes belonging to four genera: Glomus, Acaulospora Gigaspora and Disversispora and three families: Diversisporales, Glomérales and Paraglomérales were observed. An important variability of spore densities was observed from one production areas to another with a higher abundance in the production areas of Copargo estimated at 3584 spores/100g soil. The biological diversity indexes as Shannon (0.0311), Simpson (0.0204) and Hill (0.0235), varied significantly (p < 0.05) from one production areas to another. There was significant correlation between the parameters studied, particularly between the physico-chemical parameters of the soils and between the physico-chemical parameters and the biological diversity indexes. For the mycorrhization parameters, the mycorhization frequencies did not vary from one production areas to another, unlike the intensities, which significantly varied from one production areas to another (2.31% to 24.62%). Finally, this study revealed that the physico-chemical parameters of the soils had an influence on the other parameters studied. Moreover, there were an abundance and a significant diversification of AMFs associated with soybean in the different production areas, which are influenced by certain physico-chemical soil parameters.展开更多
In arid and semi-arid regions, the growth and development of cultivated plants, especially tomato (Solanum lycopersicum L.), are severely limited by water deficit. Thus, to cope with this constraint, the plant establi...In arid and semi-arid regions, the growth and development of cultivated plants, especially tomato (Solanum lycopersicum L.), are severely limited by water deficit. Thus, to cope with this constraint, the plant establishes symbiotic relationships with arbuscular mycorrhizal fungi (AMF) in the soil whose extension of the hyphae allows a better and deeper exploration;this notably improves the hydromineral nutrition of the plant. Therefore, the choice of fungal partner becomes crucial for the establishment of a crop in water-deficient soil. In this context, the contribution of AMF to the water stress tolerance of two varieties of tomato plants was assessed under semi-controlled conditions. Parameters, such as the mycorrhizal frequency, intensity of mycorrhization, relative mycorrhizal dependency, growth, and biochemical parameters (carbon, nitrogen, phosphorus, and proline contents) of plants subjected to three levels of water stress (T100, T70, and T30), were evaluated. The highest frequencies and intensities of mycorrhization and relative mycorrhizal dependencies were obtained with plants of the Xewel variety inoculated with Rhizophagus fasciculatus (F: 95.24%, 88.35%, and 13.64%;M: 40.52%, 37.52%, and 11.22%;D: 23.7%, 54.4%, and 78.82%) and in those of the Lady Nema variety inoculated with Claroideoglomus etunicatum (F: 95.12%, 87.01%, and 15.25%;M: 40.66%, 37.99%, and 11.42%;D: 19.27%, 57.01%, and 70.98%), respectively at water regimes of T100, T70 and T30. These same symbiotic couples recorded, at T30, the best survival rates (+ 40%) and the higher aerial (77% and 74%) and root dry weights (80% and 59%). Plants of the Xewel variety inoculated with R. fasciculatus recorded the highest contents of carbon (T70: 30.59% and T30: 21.55%) and phosphorus (T70: 0.18% and T30: 0.17%). Plants of the Lady Nema variety recorded the highest nitrogen contents with 3.51% and 3.20%, respectively at T70 and T30. Plants of the Lady Nema variety, inoculated with C. etunicatum, also recorded the highest proline contents (572.25, 739.44, and 1165 nmoles•g<sup>−1</sup> of fresh material), followed by those of the Xewel variety inoculated with R. fasciculatus (580.36, 763.65, and 1112.11 nmoles•g<sup>−1</sup> of fresh matter), respectively at T100, T70, and T30. For the Lady Nema variety, the best fungal partner is C. etunicatum, followed by R. fasciculatus and, finally, Funneliformis mosseae. However, for the plants of the Xewel variety, R. fasciculatus is the most efficient, followed by F. mosseae and C. etunicatum. This suggests that, in tomatoes, the efficiency of mycorrhizal symbiosis under water stress conditions is not only dependent on the host plant but on both associated symbiotic partners. Hence, it is a need for screening to identify the best symbiotic couples in a stressful environment.展开更多
The effect of arbuscular mycorrhizal fungi on seedling growth across the rain forest-pasture edge has not received much attention. In a tropical rain forest in eastern Mexico, the seedlings of light demanding (Ficus i...The effect of arbuscular mycorrhizal fungi on seedling growth across the rain forest-pasture edge has not received much attention. In a tropical rain forest in eastern Mexico, the seedlings of light demanding (Ficus insipida), nonsecondary light demanding (Lonchocarpus cruentus) and shade tolerant species (Nectandra ambigens, Coccoloba hondurensis) were grown and transplanted to a forest edge with three inoculation treatments (AM fungus spores and colonized roots, spores, and no inoculum). For all species, stem height, stem diameter, total dry weight, leaf area and net assimilation rate were higher in the pasture. Stem height, stem diameter and root/shoot were higher for L. cruentus, and leaf area ratio, specific leaf area and net assimilation rate were higher for F. insipida;the lowest values of almost all variables were recorded for N. ambigens. L. cruentus and C. hondurensis with mycorrhizae had the highest values for root/shoot and net assimilation rate, respectively. The lowest values of root/shoot and net assimilation rate were observed for nonlight-demanding species in the forest. There were clear trade-offs for the pioneer species between survival and growth, and in underground biomass allocation and assimilation for nonsecondary light demanding, but there was not for the shade-tolerant species.展开更多
Ecology seeks to explain species coexistence,but experimental tests of mechanisms for coexistence are difficult to conduct.We synthesized an arbuscular mycorrhizal(AM)fungal community with three fungal species that di...Ecology seeks to explain species coexistence,but experimental tests of mechanisms for coexistence are difficult to conduct.We synthesized an arbuscular mycorrhizal(AM)fungal community with three fungal species that differed in their capacity of foraging for orthophosphate(P)due to differences in soil exploration.We tested whether AM fungal species-specific hyphosphere bacterial assemblages recruited by hyphal exudates enabled differentiation among the fungi in the capacity of mobilizing soil organic P(P_(o)).We found that the less efficient space explorer,Gigaspora margarita,obtained less ^(13)C from the plant,whereas it had higher efficiencies in P_(o)mobilization and alkaline phosphatase(Al Pase)production per unit C than the two efficient space explorers,Rhizophagusintraradices and Funneliformis mosseae.Each AM fungus was associated with a distinct alp gene harboring bacterial assemblage,and the alp gene abundance and P_(o)preference of the microbiome associated with the less efficient space explorer were higher than those of the two other species.We conclude that the traits of AM fungal associated bacterial consortia cause niche differentiation.The trade-off between foraging ability and the ability to recruit effective P_(o)mobilizing microbiomes is a mechanism that allows co-existence of AM fungal species in a single plant root and surrounding soil habitat.展开更多
Arbuscular mycorrhizal fungi(AMF)can form symbiotic relationships with most crops,but their impact on the environmental migration of cadmium(Cd)in farmland is limited.A field experiment was per-formed in the rainy sea...Arbuscular mycorrhizal fungi(AMF)can form symbiotic relationships with most crops,but their impact on the environmental migration of cadmium(Cd)in farmland is limited.A field experiment was per-formed in the rainy season(May-October)for two years in Cd-polluted farmland used for maize cultivation.A fungicide(benomyl)was used to specifically inhibit native AMF growth in the farmland.The growth and Cd uptake of maize and the Cd concentration and loss in runoff and interflow were investigated.Benomyl strongly and significantly inhibited AMF colonization rate in maize roots,reduced the contents of total and easily extractable glomalin-related soil protein(GRSP)in soil and the Cd uptake in maize roots,and increased the Cd uptake in shoots.Particulate Cd was the main form of Cd loss in runoff,while dissolved Cd was the main form of Cd leaching loss at depths of 20 cm and 40 cm.Inhibiting AMF increased the Cd concentration in runoff and interflow and promoted dissolved Cd loss in runoff and interflow at 20 cm depth by 34.7%and 68.0%and particulate Cd loss by 46.4%and 19.7%,respectively.Furthermore,the AMF colonization rate in maize roots and the GRSP content in soil were significantly positively correlated with Cd uptake in roots and negatively correlated with the concentration and loss of Cd in runoff and interflow.These results indicated that the benomyl-induced inhibition of native AMF promoted Cd transfer to maize shoots and increased Cd loss via runoff and interflow from polluted farmland.展开更多
Moso bamboo(Phyllostachys Pubescens)expansion into adjacent forests has been widely reported to affect plant diversity and its association with mycorrhizal fungi in subtropical China,which will likely have significant...Moso bamboo(Phyllostachys Pubescens)expansion into adjacent forests has been widely reported to affect plant diversity and its association with mycorrhizal fungi in subtropical China,which will likely have significant impacts on soil respiration.However,there is still limited information on how Moso bamboo expansion changes soil respiration components and their linkage with microbial community composition and activity.Based on a mesh exclusion method,soil respirations derived from roots,arbuscular mycorrhizal(AM)mycelium,and free-living microbes were investigated in a pure Moso bamboo forest(expanded),an adjacent broadleaved forest(nonexpanded),and a mixed bamboo-broadleaved forest(expanding).Our results showed that bamboo expansion decreased the cumulative CO_(2)effluxes from total soil respiration,root respiration and soil heterotrophic respiration(by 19.01%,30.34%,and 29.92%on average),whereas increased those from AM mycelium(by 78.67%in comparison with the broadleaved forests).Bamboo expansion significantly decreased soil organic carbon(C)content,bacterial and fungal abundances,and enzyme activities involved in C,N and P cycling whereas enhanced the interactive relationships among bacterial communities.In contrast,the ingrowth of AM mycelium increased the activities ofβ-glucosidase and N-acetyl-β-glucosaminidase and decreased the interactive relationships among bacterial communities.Changes in soil heterotrophic respiration and AM mycelium respiration had positive correlations with soil enzyme activities and fungal abundances.In summary,our findings suggest that bamboo expansion decreased soil heterotrophic respiration by decreasing soil microbial activity but increased the contribution of AM mycelial respiration to soil C efflux,which may potentially increase soil C loss from AM mycelial pathway.展开更多
Nitrogen(N) runoff from paddy fields serves as one of the main sources of water pollution. Our aim was to reduce N runoff from paddy fields by fertilizer management and inoculation with arbuscular mycorrhizal fungi(AM...Nitrogen(N) runoff from paddy fields serves as one of the main sources of water pollution. Our aim was to reduce N runoff from paddy fields by fertilizer management and inoculation with arbuscular mycorrhizal fungi(AMF). In northeast China, Shuangcheng city in Heilongjiang province, a field experiment was conducted, using rice provided with 0%, 20%, 40%, 60%, 80%,and 100% of the local norm of fertilization(including N, phosphorus and potassium), with or without inoculation with Glomus mosseae. The volume, concentrations of total N(TN),dissolved N(DN) and particulate N(PN) of runoff water were measured. We found that the local norm of fertilization led to 18.9 kg/ha of N runoff during rice growing season, with DN accounting for 60%–70%. We also found that reduction in fertilization by 20% cut down TN runoff by 8.2% while AMF inoculation decreased N runoff at each fertilizer level and this effect was inhibited by high fertilization. The combination of inoculation with AMF and 80% of the local norm of fertilization was observed to reduce N runoff by 27.2%. Conclusively, we suggested that the contribution of AMF inoculation combined with decreasing fertilization should get more attention to slow down water eutrophication by reducing N runoff from paddy fields.展开更多
文摘The objective of this work was to carry out a morphological characterization of arbuscular mycorrhizal fungi in the rhizosphere of Xanthosoma sagittifolium L. Schott plants. The plant material used was the white and red cultivars of X. sagittifolium, belonging to age intervals of 3 - 6, 6 - 9, and 9 - 12 months. Three harvest sites were chosen in the Central Region of Cameroon. In each site, soil from the rhizosphere and plant roots was collected in a randomized manner. In the field, the agronomic parameters were evaluated. The physicochemical characteristics of the soils, the mycorrhization index, and the morphological characterization of the mycorrhizal types of each site were carried out. The results obtained show that the agronomic growth parameters varied significantly using the Student Newman and Keuls Test depending on the harvest sites. The soils’ pH in all sites was acidic and ranged between 4.6 and 5.8. The Nkometou site has a loamy texture while the Olembe and Soa sites have loam-clay-sandy and loam-clay textures respectively. The highest mycorrhization frequencies appeared at the Nkometou site, with 75 and 87.33% of the white and red cultivars plant roots at 6 - 9 and 3 - 6 months. The relative abundance of AMF arbuscular mycorrhizal fungal spores in the rhizosphere of X. sagittifolium plants varied with age and cultivar. There were 673 spores between 9 - 12 months in Nkometou in the red cultivar. Six AMF genera were identified in all the different soils collected: Acaulospora sp., Funneliformis sp., Gigaspora sp., Glomus sp., Scutellospora sp., and Septoglomus sp. The genus Glomus sp. was the most present at all age intervals in both cultivars.
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AGER-Fondazioni in rete per la ricerca agroalimentare(https://www.progettoager.it/)(Grant No.2010-2369)by Joint Programming Initiative on Agriculture,Food Security and Climate Change(FACCE-JPI)project Green Rice(Sustainable and environmental friendly rice cultivation systems in Europe).
文摘Alternate wetting and drying(AWD)system,in which water has been reduced by approximately 35%with an increased occurrence of beneficial arbuscular mycorrhizal(AM)symbiosis and no negative impact on rice yield,was proposed to utilize water and nutrients more sustainable.In this study,we selected six rice cultivars(Centauro,Loto,Selenio,Vialone nano,JSendra and Puntal)grown under AWD conditions,and investigated their responsiveness to AM colonization and how they select diverse AM taxa.In order to investigate root-associated AM fungus communities,molecular cloning-Sanger sequencing on small subunit rDNA data were obtained from five out of the six rice cultivars and compared with Next Generation Sequencing(NGS)data,which were previously obtained in Vialone nano.The results showed that all the cultivars were responsive to AM colonization with the development of AM symbiotic structures,even if with differences in the colonization and arbuscule abundance in the root systems.We identified 16 virtual taxa(VT)in the soil compartment and 7 VT in the root apparatus.We emphasized that the NGS analysis gives additional value to the results thanks to a more in-depth reading of the less represented AM fungus taxa.
基金supported by the Key R&D Program of Yunnan Province,China(Grant No.202103AC100003202101AS070228)+2 种基金the Major Special Project of the Ministry of Science and Technology(2021YFD10002022021YFD1601003)and the National Natural Science Foundation of China(Grant No.31860075),thank you.
文摘Arbuscular mycorrhizal fungi(AMF)are important members of the plant microbiome and affect the uptake and transfer of mineral elements by forming a symbiotic relationship with plant roots.Nitrogen(N),as an important mineral element,can directly affect plant growth and development at different N levels.It has been confirmed that inoculation with AMF can improve the efficiency of N utilization by plants.However,there are still fewer reports on the dynamic relationship between arbuscular mycorrhizal and plant secondary metabolites at different nitrogen levels.In this experiment,the physiological indexes and genes related to saponin synthesis were determined by applying different concentration gradients of nitrogen to the medicinal plant P.polyphylla var.yunnanensis infested by AMF as the test material.It was found that nitrogen addition increased the biomass,chlorophyll content,and nutrient content of above-and below-ground plant parts and increased the content of saponin content of P.polyphylla var.yunnanensis to some extent,but AMF inoculation increased the saponin content of P.polyphylla var.yunnanensis more significantly.AMF inoculation also promoted the expression of genes related to the saponin synthesis pathway,including 3-hydroxy-3-methylglutaryl coenzyme A synthase(HMGS),squalene epoxidase 1(SE1),and cycloartenol synthase(CAS),which is in according with the accumulation of saponin in plants.It also may increase the saponin content of AMF plants by altering the expression of P450s and UGTs related to saponin synthesis.
基金financially supported by the Beijing Natural Science Foundation,China(6202015)the National Natural Science Foundation of China(U1703232)the Hatch Project(ALA014-1-16016)funded by the National Institute of Food and Agriculture,US Department of Agriculture。
文摘The species richness and propagule number of arbuscular mycorrhizal fungi(AMF)are high in intensively-managed agricultural soils.Past research has shown that AMF improve crop phosphorus(P)uptake under low soil P conditions,however it is unclear if AMF play a role in high Olsen-P soils.In this study,we investigated whether native fungal benefits exist under high P input field conditions in-situ and contribute to P utilization.We installed in-grow tubes which were sealed with different membrane pore sizes(30 or 0.45μm)to allow or prevent AMF hyphae access to the hyphal compartment and prevent cotton roots from penetrating the chamber.We used the depletion of soil available P(Olsen-P)in the hyphae accessed compartment to indicate P uptake by the native AMF community.Our results showed that the native AMF mediated P depletion and microbial biomass P(MBP)turnover and caused the largest Olsen-P depletion ratio and MBP turnover ratio in the high P treatments(Olsen-P:78.29 mg kg^(-1)).The cotton roots in each fertilization regime were colonized by a unique AMF community and Glomus and Paraglomus were the dominant genera,implying the longterm fertilization regimes domesticated the AMF community.We conclude that native AMF caused the P depletion and P turnover even under high soil Olsen-P conditions.
基金This work was supported by the National Natural Science Foundation of China(31960616)the Construction of Modern Agriculture(tea)Industry Technology System(CARS-19)(China)+2 种基金the Key Agricultural Science and Technology Foundation of Guizhou Province([2016]2570)(China)the Science and Technology Foundation of Guizhou Province(2013[2155])(China)the High-value Patent Cultivation Project of Guizhou Province Academy of Agricultural Sciences([2018]02)(China).
文摘Hevea brasiliensis is one of the important economic trees with a great economic value for natural rubber production.Symbiosis between roots of H.brasiliensis and arbuscular mycorrhizal fungi(AMF)is widely recognized,and can provide a range of benefits for both of them.Hainan Island harbors is one of the largest plantations of H.brasiliensis in China,whereas the information regarding the diversity of AMF in the rhizosphere of H.brasiliensis on this island is scarce.The diversity of AMF species in the rhizosphere of rubber tree plantations in Hainan was investigated in this study.A total of 72 soil samples from the rhizosphere of H.brasiliensis RY7-33-97 were collected.These included 48 samples from plantations in 11 cities or counties that had been planted for 15–25 years,and 24 samples from a demonstrating plantation site of the China National Rubber Tree Germplasm Repository representing plantations with tree plantation ages from one to 40 year-old.Collectively,a total of 68 morphotypes of AMF,belonging to the genera of Archaeospora(1),Glomus(43),Acaulospora(18),Entrophospora(3),Scutellospora(2),and Gigaspora(1)were isolated and identified,as per morphological characteristics of spores presented in the collected soil samples.Glomus(Frequency,F=100%)and Acaulospora(F=100%)were the predominant genera,and A.mellea(F=63.9%)and A.scrobiculata(F=63.9%)were the predominant species.AMF species differed significantly among collected sites in spore density(SD,290.7–2,186.7 spores per 100 g dry soil),species richness(SR,4.3–12.3),and Shannon-Weiner index of diversity(H,1.24–2.24).SD was negatively correlated with available phosphorus level in the soil;SR was positively correlated with soil total phosphorus content;and H was positively correlated with levels of soil organic matter and total phosphorus.Similarly,SD,SR,and H were also correlated with H.brasiliensis plantation age,and an increasing trend was observed up to 40 years.These results suggest that the AMF community was complex and ubiquitous in the island plantation ecosystems of H.brasiliensis,with high species abundance and diversity.Soil factors and plantation age dramatically affected AMF diversity at species level.
基金Supported by Beijing Municipal Natural Science Foundation(6142005)
文摘[Objective] This study aimed to investigate the effects of 5 kinds of arbuscular mycorrhizal fungi( Acaulospora mellea,Glomus mosseae,Glomus versiforme,Glomus aggregatum,Glomus etunicatum) on the growth and protective enzyme activity of Glycyrrhiza uralensis Fisch. [Method] The growth indicators and protective enzymes activity of glycyrrhiza plants inoculated and uninoculated with fungi were compared. [Result] The plant height,basal diameter,main root length,aboveground fresh weight,underground fresh weight,aboveground dry weight and underground dry weight of the inoculated glycyrrhiza plants were increased significantly compared with those in the control( non-inoculation) group. In the inoculated glycyrrhiza plants,the growth index was significantly increased compared with that in the control group( P <0. 05); the activities of superoxide dismutase( SOD) and peroxidase( POD) increased first and then decreased; and the activity of catalase( CAT) showed a continuous rising trend. The effects of different inoculants on the growth of G. uralensis were significantly different.[Conclusion]G. etunicatum,G. mosseae and G. aggregatum had a significant effect on the growth of G. uralensis,and were superior to other fungi in resisting the adverse environment.
文摘We investigated the arbuscular mycorrhizal fungi(AMF)status of ten nurseries suitable for restoration of dry evergreen Afromontane forests in Ethiopia.We quantified AMF root colonization(RC)and spore abundance(SA)in seedlings of nine native tree species namely Acacia abyssinica Hochst.ex Benth.,Cordia africana Lam.,Dovyalis abyssinica(A.Rich.)Warb.,H agenia abyssinica J.F.Gmel.,Juniperus procera Hochst.ex Endl.,Millettia ferruginea(Hochst.)Baker,Olea europaea L.subsp.c uspidata(Wall.ex G.Don)Cif.,Podocarpus falcatus(Thunb.)R.Br.ex Mirb.and Prunus africana(Hook.f.)Kalkman.We used the ink and vinegar method to stain AMF in roots.RC levels ranged from 8.00 to 99.67%and were generally higher than the RC levels reported from other similar nurseries in Ethiopia.SA levels ranged from 1 to 25 spores g~(-1)and werecomparable with some reports from the field in Ethiopia but they were lower than levels reported by another similar study.RC was more affected by host species than nursery location,while the reverse was true for SA.The results also showed that nursery management could improve AMF status among seedlings.When all nursery tree species were considered,RC and SA levels were unrelated.No strong correlation existed between the nursery management variables considered and RC or SA.However,considering C.africana,J.procera and P.falcatus separately,RC-age(r_(s)=0.829,P=0.042)correlation for O.europaea and RC-pot diameter(r_(s)=0.820,P=0.046),RC-pot volume(r_(s)=0.928,P=0.008)and SA-age(r_(s)=0.943,P=0.005)correlations for C.africana,were significant,strong and positive.Generally,most of the tree species and particularly,early-mid successional tree species had sufficient AMF inoculum.Hence,only the mid-late successional tree species;J.procera,P.falcatus,and P.africana may require AMF inoculation,preferably,during filed planting.Based on our results,age and pot volume were identified to be important variables potentially affecting RC and SA.To better understand the effects of these and other nursery management variables,additional study is required.We demonstrated for the first time that black Hero ink is suitable for staining root AMF and can be used in future AMF research.
基金supported by the TÉT-10-1-2011-0648“Hungarian-Vietnamese intergovernmental cooperation program”by 53/2011/HĐ-NĐT(MOST-VietNam)by the TÁMOP 4.2.2/B-10/1-2010-011“Develop-ment of a complex educational assistance/support system for talented students and prospective researchers at the Szent István University”project.
文摘The rising claim for more environmental friendly and healthy agriculture is a strong incentive to find alternative strategies to replace the use of mineral fertilizer and pesticide. Arbuscular mycorrhizal fungi (AMF), a main component of soil microbiota, represent a promising tool as providers of key ecological services. The present work represented one of the first attempts to study, under a morphological and molecular point of view, the AMF communities associated to some strategic crops in Vietnam. The findings about the AMF morphotypes dominant in different crop systems could be a starting point for the development of well performing and adapted inocula suitable for the application in field.
基金a research project(No.IFGTB/NFRP 168)of the Indian Council of Forestry Research and Education,Dehra Dun.
文摘The objective of this research was to improve the growth and biomass of Pterocarpus santalinus L.f.(an endangered leguminous tree)using native microbial symbionts such as arbuscular mycorrhizal fungi and Rhizobium associated with native populations of P.santalinus.The native arbuscular mycorrhizal fungi isolated from P.santalinus soils were identifi ed as(1)Glomus fasciculatum;(2)Glomus geosporum;and Glomus aggregatum.A nitrogenfi xing microbial symbiont was isolated from the root nodules of P.santalinus and identifi ed as Rhizobium aegyptiacum by 16s rRNA gene sequencing.These microbial symbionts were inoculated individually and in combination into P.santalinus seedling roots.After 90 days,growth and biomass had improved compared with uninoculated controls.Shoot and root lengths,number of leaves,stem circumference,number of root nodules,biomass,nutrient uptake and seedling quality index were signifi cantly increased by a combined inoculation of arbuscular mycorrhizal fungi+Rhizobium aegyptiacum.It was concluded that native microbial symbionts positively infl uenced P.santalinus seedling growth which will be helpful for successful fi eld establishment.
基金the National Key Research and Development Program of China(No.2017YFE0119100)the National Natural Science Foundation of China(No.42107513)the Key Research and Development Program of Gansu(No.21YF5FA151)。
文摘Nitraria tangutorum Bobr.,a typical xero-halophyte,can be used for vegetation restoration and reconstruction in arid and semiarid regions affected by salinity.However,global climate change and unreasonable human activity have exacerbated salinization in arid and semi-arid regions,which in turn has led to the growth inhibition of halophytes,including N.tangutorum.Arbuscular mycorrhizal fungi(AMF)and plant growth-promoting rhizobacteria(PGPR)have the potential to improve the salt tolerance of plants and their adaptation to saline soil environments.In this study,the effects of single and combined inoculations of AMF(Glomus mosseae)and PGPR(Bacillus amyloliquefaciens FZB42)on N.tangutorum were evaluated in severe saline soil conditions.The results indicate that AMF and PGPR alone may not adapt well to the real soil environment,and cannot ensure the effect of either growth promotion or salt-tolerance induction on N.tangutorum seedlings.However,the combination of AMF and PGPR significantly promoted mycorrhizal colonization,increased biomass accumulation,improved morphological development,enhanced photosynthetic performance,stomatal adjustment ability,and the exchange of water and gas.Co-inoculation also significantly counteracted the adverse effect of salinity on the soil structure of N.tangutorum seedlings.It is concluded that the effectiveness of microbial inoculation on the salt tolerance of N.tangutorum seedlings depends on the functional compatibility between plants and microorganisms as well as the specific combinations of AMF and PGPR.
文摘The effects of biochar(BC),arbuscular mycorrhizal fungi(AM),nitrogen(N)and their composite treatments(BC+N,AM+N,BC+AM and BC+AM+N)application on Cichorium intybus L.(C.intybus L.)nutrient uptake,soil properties and cadmium(Cd)accumulation were investigated in Cd contaminated soil(0.11 mg·kg^(-1)).The results showed that the addition of BC increased the rate of mycorrhizal infection.However,the addition of N slightly inhibited mycorrhizal colonization,and the shoot and root bioaccumulation of chicory was positively influenced by BC and N when inoculated with AM fungi.Compared with the single component treatment(AM,BC or N)or two-component treatment(BC+N,AM+N or BC+AM),the three-component composite treatment(BC+AM+N)had the highest shoot bioaccumulation,whereas BC+AM treatment was considered the best for root biomass bioaccumulation.Compared with the control treatment,the single component treatment(AM,BC or N)and the composite treatment resulted in an overall improvement of the chicory shoot,root related nutrient uptake(N,P,K,Mg,Ca,Mn and Fe)and some soil physicochemical properties;in addition,these treatments showed better results than BC+AM+N and BC+AM treatments.Among the Cd-related indexes,Cd concentrations in the shoot,root and soil of C.intybus L.were reduced through treatment with AM and BC.However,a lower bioconcentration coefficient(BCF)and a higher transfer coefficient(TF)were observed in both treatments,and the most desirable effect was observed following the combination treatment(BC+AM).Compared with other single management,the shoot and root Cd concentrations of C.intybus L.after the management of N alone were higher,and the value of BCF(2.63%)was higher,but the value of TF(1.05%)was lower.Indexes related to Cd improved concurrently following the application of N in combination with BC or AM.Therefore,in Cd contaminated soils,single or combined application of BC,AM and N could promote chicory growth and nutrient uptake and improve some soil physicochemical properties.However,N should not be applied alone and needed to be combined with AM and BC;furthermore,it was evident that the treatment with the three composites(BC+AM+N)was optimal from an application point of view.
文摘Salinity is a major problem that seriously impacts agricultural production, particularly that of tomato (Solanum lycopersicum L.). However, the plant has the ability to associate with Arbuscular Mycorrhizal Fungi to better tolerate salt stress. Thus, thanks to the extension of the AMF hyphae, the hydromineral nutrition and the tolerance to excess toxic ions (Na<sup>+</sup> and Cl<sup>-</sup>) of the plant are optimized. In this context, the contribution of AMF to the salt stress tolerance of two tomato varieties under semi-controlled conditions was studied. To do this, the frequency and intensity of mycorrhization, the relative mycorrhizal dependency, the survival rates, the aerial and root dry weights, the mineral (P, K<sup>+</sup>, Na<sup>+</sup>) and proline contents of the plants subjected to four levels of salinity [0, 70, 140 and 210 mM of NaCl] were evaluated. All the parameters assessed appeared to be dependent on the variety, the fungal strain and the NaCl concentration. With the Lady Nema variety, inoculation with the Claroideoglomus etunicatum strain at [NaCl 140 mM] resulted in the highest frequencies (54%), intensities (40.47%), and relative mycorrhizal dependencies (19.65%). This same symbiotic couple recorded high survival rates (55%) and aerial (2.03 g) and root (0.50 g) dry weights. Significant contents of K<sup>+ </sup>(Leaves: 7.5 mg⋅g<sup>-1</sup>;Roots: 4.4 mg⋅g<sup>-1</sup> of dry matter), P (Leaves: 15.15 mg⋅g-1</sup> of dry matter) and proline (975 nmoles⋅g-1</sup> of fresh matter) were also recorded by this pair, with the lowest Na<sup>+</sup> contents (Leaves: 1.93 mg⋅g-1</sup>;Roots: 0.96 mg⋅g-1</sup> of dry matter). For the Mongal variety, at [NaCl 140 mM], the highest frequencies (50.36%), intensities (35.14%) and relative mycorrhizal dependencies (43.95%) were obtained thanks to inoculation with Rhizophagus fasciculatus. The highest survival rates (59%) and aerial (2.58 g) and root (0.79 g) dry weights were also obtained with this symbiotic couple. The contents of K<sup>+</sup> (Leaves: 6.1 mg⋅g-1</sup>;Roots: 3.09 mg⋅g-1 </sup>of dry matter), P (Leaves: 12.49 mg⋅g-1</sup> of dry matter) and proline (942 nmoles⋅g-1</sup> of fresh matter) the most important and those in Na<sup>+</sup> the lowest (Leaves: 2.03 mg⋅g-1</sup>;Roots: 1.53 mg⋅g-1</sup> of dry matter) were also recorded for this same pair. Thus, the best fungal partner for the Lady Nema variety is C. etunicatum, followed by F. mosseae and R. fasciculatus, while for the Mongal variety it is R. fasciculatus, followed by C. etunicatum and F. mosseae.
文摘Arbuscular Mycorrhizal Fungi (AMFs) could be used to sustainably improve crop yields. The present study evaluated the diversity of AMF species associated with soybean (Glycine max L. Merill) in main soybean-producing areas in Benin. Composite soil samples from 13 production areas at a rate of 04 villages per production areas were collected. A spore trapping device was set up to reveal the diversity of spores. The physical and chemical properties of the soils, the frequency and intensity of mycorrhization of roots, and the diversity of AMF spores were determined in the soil samples following trapping. As result, eight morphotypes belonging to four genera: Glomus, Acaulospora Gigaspora and Disversispora and three families: Diversisporales, Glomérales and Paraglomérales were observed. An important variability of spore densities was observed from one production areas to another with a higher abundance in the production areas of Copargo estimated at 3584 spores/100g soil. The biological diversity indexes as Shannon (0.0311), Simpson (0.0204) and Hill (0.0235), varied significantly (p < 0.05) from one production areas to another. There was significant correlation between the parameters studied, particularly between the physico-chemical parameters of the soils and between the physico-chemical parameters and the biological diversity indexes. For the mycorrhization parameters, the mycorhization frequencies did not vary from one production areas to another, unlike the intensities, which significantly varied from one production areas to another (2.31% to 24.62%). Finally, this study revealed that the physico-chemical parameters of the soils had an influence on the other parameters studied. Moreover, there were an abundance and a significant diversification of AMFs associated with soybean in the different production areas, which are influenced by certain physico-chemical soil parameters.
文摘In arid and semi-arid regions, the growth and development of cultivated plants, especially tomato (Solanum lycopersicum L.), are severely limited by water deficit. Thus, to cope with this constraint, the plant establishes symbiotic relationships with arbuscular mycorrhizal fungi (AMF) in the soil whose extension of the hyphae allows a better and deeper exploration;this notably improves the hydromineral nutrition of the plant. Therefore, the choice of fungal partner becomes crucial for the establishment of a crop in water-deficient soil. In this context, the contribution of AMF to the water stress tolerance of two varieties of tomato plants was assessed under semi-controlled conditions. Parameters, such as the mycorrhizal frequency, intensity of mycorrhization, relative mycorrhizal dependency, growth, and biochemical parameters (carbon, nitrogen, phosphorus, and proline contents) of plants subjected to three levels of water stress (T100, T70, and T30), were evaluated. The highest frequencies and intensities of mycorrhization and relative mycorrhizal dependencies were obtained with plants of the Xewel variety inoculated with Rhizophagus fasciculatus (F: 95.24%, 88.35%, and 13.64%;M: 40.52%, 37.52%, and 11.22%;D: 23.7%, 54.4%, and 78.82%) and in those of the Lady Nema variety inoculated with Claroideoglomus etunicatum (F: 95.12%, 87.01%, and 15.25%;M: 40.66%, 37.99%, and 11.42%;D: 19.27%, 57.01%, and 70.98%), respectively at water regimes of T100, T70 and T30. These same symbiotic couples recorded, at T30, the best survival rates (+ 40%) and the higher aerial (77% and 74%) and root dry weights (80% and 59%). Plants of the Xewel variety inoculated with R. fasciculatus recorded the highest contents of carbon (T70: 30.59% and T30: 21.55%) and phosphorus (T70: 0.18% and T30: 0.17%). Plants of the Lady Nema variety recorded the highest nitrogen contents with 3.51% and 3.20%, respectively at T70 and T30. Plants of the Lady Nema variety, inoculated with C. etunicatum, also recorded the highest proline contents (572.25, 739.44, and 1165 nmoles•g<sup>−1</sup> of fresh material), followed by those of the Xewel variety inoculated with R. fasciculatus (580.36, 763.65, and 1112.11 nmoles•g<sup>−1</sup> of fresh matter), respectively at T100, T70, and T30. For the Lady Nema variety, the best fungal partner is C. etunicatum, followed by R. fasciculatus and, finally, Funneliformis mosseae. However, for the plants of the Xewel variety, R. fasciculatus is the most efficient, followed by F. mosseae and C. etunicatum. This suggests that, in tomatoes, the efficiency of mycorrhizal symbiosis under water stress conditions is not only dependent on the host plant but on both associated symbiotic partners. Hence, it is a need for screening to identify the best symbiotic couples in a stressful environment.
基金the Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica(PAPIIT)of the Universidad Nacional Autónoma de México(UNAM Grant IN-235402)the Secretaría de Medio Ambiente y Recursos Naturales-Consejo Nacional de Ciencia y Tecnología(Grant 2002-c01-668),and the Packard Foundation.
文摘The effect of arbuscular mycorrhizal fungi on seedling growth across the rain forest-pasture edge has not received much attention. In a tropical rain forest in eastern Mexico, the seedlings of light demanding (Ficus insipida), nonsecondary light demanding (Lonchocarpus cruentus) and shade tolerant species (Nectandra ambigens, Coccoloba hondurensis) were grown and transplanted to a forest edge with three inoculation treatments (AM fungus spores and colonized roots, spores, and no inoculum). For all species, stem height, stem diameter, total dry weight, leaf area and net assimilation rate were higher in the pasture. Stem height, stem diameter and root/shoot were higher for L. cruentus, and leaf area ratio, specific leaf area and net assimilation rate were higher for F. insipida;the lowest values of almost all variables were recorded for N. ambigens. L. cruentus and C. hondurensis with mycorrhizae had the highest values for root/shoot and net assimilation rate, respectively. The lowest values of root/shoot and net assimilation rate were observed for nonlight-demanding species in the forest. There were clear trade-offs for the pioneer species between survival and growth, and in underground biomass allocation and assimilation for nonsecondary light demanding, but there was not for the shade-tolerant species.
基金supported by the National Natural Science Foundation of China (32272807,U1703232)the National Key Research and Development Program of China (2017YFD0200200)。
文摘Ecology seeks to explain species coexistence,but experimental tests of mechanisms for coexistence are difficult to conduct.We synthesized an arbuscular mycorrhizal(AM)fungal community with three fungal species that differed in their capacity of foraging for orthophosphate(P)due to differences in soil exploration.We tested whether AM fungal species-specific hyphosphere bacterial assemblages recruited by hyphal exudates enabled differentiation among the fungi in the capacity of mobilizing soil organic P(P_(o)).We found that the less efficient space explorer,Gigaspora margarita,obtained less ^(13)C from the plant,whereas it had higher efficiencies in P_(o)mobilization and alkaline phosphatase(Al Pase)production per unit C than the two efficient space explorers,Rhizophagusintraradices and Funneliformis mosseae.Each AM fungus was associated with a distinct alp gene harboring bacterial assemblage,and the alp gene abundance and P_(o)preference of the microbiome associated with the less efficient space explorer were higher than those of the two other species.We conclude that the traits of AM fungal associated bacterial consortia cause niche differentiation.The trade-off between foraging ability and the ability to recruit effective P_(o)mobilizing microbiomes is a mechanism that allows co-existence of AM fungal species in a single plant root and surrounding soil habitat.
基金supported by the National Natural Science Foundation of China(Nos.42177381 and 41661056)the Reserve Talents Fund for Young and Middle-Aged Academic and Technological Leaders in Yunnan Province(Nos.2018HB043 and 202005AC160038).
文摘Arbuscular mycorrhizal fungi(AMF)can form symbiotic relationships with most crops,but their impact on the environmental migration of cadmium(Cd)in farmland is limited.A field experiment was per-formed in the rainy season(May-October)for two years in Cd-polluted farmland used for maize cultivation.A fungicide(benomyl)was used to specifically inhibit native AMF growth in the farmland.The growth and Cd uptake of maize and the Cd concentration and loss in runoff and interflow were investigated.Benomyl strongly and significantly inhibited AMF colonization rate in maize roots,reduced the contents of total and easily extractable glomalin-related soil protein(GRSP)in soil and the Cd uptake in maize roots,and increased the Cd uptake in shoots.Particulate Cd was the main form of Cd loss in runoff,while dissolved Cd was the main form of Cd leaching loss at depths of 20 cm and 40 cm.Inhibiting AMF increased the Cd concentration in runoff and interflow and promoted dissolved Cd loss in runoff and interflow at 20 cm depth by 34.7%and 68.0%and particulate Cd loss by 46.4%and 19.7%,respectively.Furthermore,the AMF colonization rate in maize roots and the GRSP content in soil were significantly positively correlated with Cd uptake in roots and negatively correlated with the concentration and loss of Cd in runoff and interflow.These results indicated that the benomyl-induced inhibition of native AMF promoted Cd transfer to maize shoots and increased Cd loss via runoff and interflow from polluted farmland.
基金funded by the National Natural Science Foundation of China(Nos.31971631,32271850)Natural Science Foundation of Zhejiang Province under grant number LZ22C160001.
文摘Moso bamboo(Phyllostachys Pubescens)expansion into adjacent forests has been widely reported to affect plant diversity and its association with mycorrhizal fungi in subtropical China,which will likely have significant impacts on soil respiration.However,there is still limited information on how Moso bamboo expansion changes soil respiration components and their linkage with microbial community composition and activity.Based on a mesh exclusion method,soil respirations derived from roots,arbuscular mycorrhizal(AM)mycelium,and free-living microbes were investigated in a pure Moso bamboo forest(expanded),an adjacent broadleaved forest(nonexpanded),and a mixed bamboo-broadleaved forest(expanding).Our results showed that bamboo expansion decreased the cumulative CO_(2)effluxes from total soil respiration,root respiration and soil heterotrophic respiration(by 19.01%,30.34%,and 29.92%on average),whereas increased those from AM mycelium(by 78.67%in comparison with the broadleaved forests).Bamboo expansion significantly decreased soil organic carbon(C)content,bacterial and fungal abundances,and enzyme activities involved in C,N and P cycling whereas enhanced the interactive relationships among bacterial communities.In contrast,the ingrowth of AM mycelium increased the activities ofβ-glucosidase and N-acetyl-β-glucosaminidase and decreased the interactive relationships among bacterial communities.Changes in soil heterotrophic respiration and AM mycelium respiration had positive correlations with soil enzyme activities and fungal abundances.In summary,our findings suggest that bamboo expansion decreased soil heterotrophic respiration by decreasing soil microbial activity but increased the contribution of AM mycelial respiration to soil C efflux,which may potentially increase soil C loss from AM mycelial pathway.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment (No. 2012ZX07201003)the National Natural Science Foundation of China (No. 31570505)+1 种基金the Natural Science Foundation of Heilongjiang Province,China (No. E201206)the State Key Lab of Urban Water Resource and Environment (Harbin Institute of Technology) (No. 2014TS05)
文摘Nitrogen(N) runoff from paddy fields serves as one of the main sources of water pollution. Our aim was to reduce N runoff from paddy fields by fertilizer management and inoculation with arbuscular mycorrhizal fungi(AMF). In northeast China, Shuangcheng city in Heilongjiang province, a field experiment was conducted, using rice provided with 0%, 20%, 40%, 60%, 80%,and 100% of the local norm of fertilization(including N, phosphorus and potassium), with or without inoculation with Glomus mosseae. The volume, concentrations of total N(TN),dissolved N(DN) and particulate N(PN) of runoff water were measured. We found that the local norm of fertilization led to 18.9 kg/ha of N runoff during rice growing season, with DN accounting for 60%–70%. We also found that reduction in fertilization by 20% cut down TN runoff by 8.2% while AMF inoculation decreased N runoff at each fertilizer level and this effect was inhibited by high fertilization. The combination of inoculation with AMF and 80% of the local norm of fertilization was observed to reduce N runoff by 27.2%. Conclusively, we suggested that the contribution of AMF inoculation combined with decreasing fertilization should get more attention to slow down water eutrophication by reducing N runoff from paddy fields.
