Fencing for grazing exclusion is regarded as a traditional and effective method for the natural restoration of degraded alpine steppe,and it effectively promotes plant growth and enhances soil carbon stocks.Arbuscular...Fencing for grazing exclusion is regarded as a traditional and effective method for the natural restoration of degraded alpine steppe,and it effectively promotes plant growth and enhances soil carbon stocks.Arbuscular mycorrhizal fungi(AMF)are essential microorganisms in grassland that play a major role in plant-derived C translocation into the soil.However,the effects of fencing on AMF communities and their contributions to soil carbon sequestration are still unclear.In this study,alpine steppe areas with three different fencing durations(free grazing,medium-term fencing for 5-6 years and long-term fencing for more than 10 years)in the northern Tibetan Plateau were selected to explore the effects of grazing exclusion on AMF communities and their roles in soil carbon sequestration.The results showed that medium-and long-term fencing significantly increased both plant aboveground biomass and soil organic carbon(SOC)content.The AMF community composition varied significantly during different fencing durations,with a dramatic increase in the relative abundance of Glomus but a significant reduction in the relative abundance of Diversispora with longer fencing time.Medium-term fencing significantly increased AMF richness and the ShannonWiener index.Meanwhile,fencing significantly increased hyphal length density(HLD),glomalin-related soil protein(GRSP)and the proportion of macroaggregates(250-2,000μm),all of which contribute positively to SOC.Structural equation modeling revealed that fencing time positively influenced HLD and the AMF community composition,subsequently affecting T-GRSP,which was tightly correlated with SOC.Our findings suggest the potentially important contribution of AMF to SOC sequestration,so more attention should be paid to AMF during alpine steppe fencing,particularly for enhancing the efficiency of degraded grassland restoration efforts.展开更多
As a major subunit of the exocyst complex,members of the EXO70 family have mainly been shown to play roles in cell polarity and morphogenesis in Arabidopsis,but their roles in plant endosymbiosis,such as with arbuscul...As a major subunit of the exocyst complex,members of the EXO70 family have mainly been shown to play roles in cell polarity and morphogenesis in Arabidopsis,but their roles in plant endosymbiosis,such as with arbuscular mycorrhizal fungi(AMF),have rarely been reported.Here,using knockout and overexpression lines,we show that OsEXO70L2,which encodes a divergent EXO70 protein in rice,controls the number of primary roots and is essential for large lateral root formation.Furthermore,the OsEXO70L2 mutant sr1 displayed rare internal AMF hyphaeand no arbuscules.We also found that AMF sporulation can occur in roots despite low colonization and that AMF colonization and sporulation are modulated by photoperiod and co-culture with clover.Finally,genes related to auxin homeostasis were found to be affected in the OsEXO70L2 knockout or overexpression lines,suggesting that auxin is at least partly responsible for the phenotypes.This study provides new perspectives on the role of the exocyst complex during root development and AM in rice.展开更多
The mutualistic symbiotic system formed by clumping arbuscular mycorrhizal fungi(AMF)and plants can remediate heavy metal-contaminated soils.However,the specific mechanisms underlying the interaction between AMF and i...The mutualistic symbiotic system formed by clumping arbuscular mycorrhizal fungi(AMF)and plants can remediate heavy metal-contaminated soils.However,the specific mechanisms underlying the interaction between AMF and inter-root microbial communities,particularly their impact on organic phosphorus(P)cycling,remain unclear.This study investigated the gene regulation processes involved in inter-root soil phosphorus cycling in wetland plants,specifically Iris tectorum,following inoculation with AMF under varying concentrations of chromium(Cr)stress.Through macro-genome sequencing,we analyzed the composition and structure of the inter-root soil microbial community associated with Iris tectorum under greenhouse pot conditions.The results demonstrated significant changes in the diversity and composition of the inter-root soil microbial community following AMF inoculation,with Proteobacteria,Actinobacteria,Chloroflexi,Acidobacteria,and Bacteroidetes being the dominant taxa.Under Cr stress,species and gene co-occurrence network analysis revealed that AMF promoted the transformation process of organic phosphorus mineralization and facilitated inorganic phosphorus uptake.Additionally,network analysis of functional genes indicated strong aggregation of(pstS,pstA,pstC,TC.PIT,phoR,pp-gppA)genes,which collectively enhanced phosphorus uptake by plants.These findings shed light on the inter-root soil phosphorus cycling process during the co-remediation of Cr-contaminated soil by AMF-Iris tectorum symbiosis,providing valuable theoretical support for the application of AMF-wetland plant symbiosis systems to remediate heavy metal-contaminated soil.展开更多
[Objective] The purpose was to study the effects of different arbuscular mycorrhizal fungi strains（AMF）on the mineral nutrition and antioxidant enzymes of Chrysanthemum morifolium.[Method] The pot experiment was con...[Objective] The purpose was to study the effects of different arbuscular mycorrhizal fungi strains（AMF）on the mineral nutrition and antioxidant enzymes of Chrysanthemum morifolium.[Method] The pot experiment was conducted in the greenhouse,C.morifolium ＇Jinba＇ was inoculated with five kinds of AMF,N,P,K,malondial dehyde（MDA）content,as well as the superoxide dismutase（SOD）,peroxidase（POD） and catalase（CAT） activity in roots,leaves and petals of C.morifolium were measured at seedling and flowering stages.[Result] The G.i,G.e and G.m treatments could promote mineral nutrient absorption,increase N,P,K content in roots,leaves and petals of C.morifolium compared with the control without inoculation.The G.d、G.e and G.m treatments could significantly reduce MDA content in roots and petals,thus alleviating membrane permeability and lipid peroxidation.The G.i treatments could also improve the SOD,POD and CAT activities of C.morifolium,thereby increasing the capability of scavenging oxygen free radicals.[Conclusion] According to the comprehensive analysis,G.i was screened out as the best strain to improve mineral nutrition and antioxidant enzyme activities of C.morifolium.展开更多
Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi （AMF）, Acaulospora m...Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi （AMF）, Acaulospora mellea, Glomus diaphanum and Sclerocystis sinuosa.. The height, biomass, and absorptions of nitrogen and phosphorus of C. acuminata seedlings inoculated with AMF were investigated. The results showed that the formation of AM promoted the height growth and biomass accumulation of seedlings significantly and improved the absorption of phosphorus in seedlings. The height and biomass of mycorrhizal seedlings were 1.2 and 1.6 times higher than those of the non-mycorrhizal seedlings. The absorption of nitrogen was less influenced by the formation of AM. The nitrogen content in mycorrhizal seedling was equal to that of non-mycorrhizal seedlings. Compared with non-mycorrhizal seedlings, the nitrogen content of mycorrhizal seedlings inoculated with A. mellea changed considerably in the root, stem and leaves. The difference in nitrogen content was not significant between mycorrhizal seedlings inoculated with G. diaphanum and S. sinuosa. The AM formation stimulated the absorption of phosphorus, especially in roots, and also changed the allocation of nitrogen and phosphorus in different organs of seedlings. Compared with non-mycorrhizal seedlings, the ratio of nitrogen and phosphorus in mycorrhizal roots increased, but reduced in stem and leaves.展开更多
[Objective] This study aimed to investigate the effects of arbuscular mycor-rhizal fungi （AMF） on growth of upland rice under soil Pb contamination. [Method] Using potting method, the effects of Glomus mosseae on th...[Objective] This study aimed to investigate the effects of arbuscular mycor-rhizal fungi （AMF） on growth of upland rice under soil Pb contamination. [Method] Using potting method, the effects of Glomus mosseae on the growth of Oryzal sati-va L. under different soil Pb concentrations （0, 300, 600 mg/kg） were investigated. [Result] According to the results, the mycorrhizal colonization rate of upland rice in-oculated with Glomus mosseae was significantly reduced （P〈0.05） with the increase of Pb concentration in soil. Compared with non-inoculation treatment, inoculation of arbuscular mycorrhizal fungi significantly improved the biomass of upland rice and Pb concentration of upland rice roots with addition of 300 mg/kg Pb but significantly reduced Pb concentration of upland rice shoots, which was consistent with the re-duced R/S （P〈0.05）; with addition of 600 mg/kg Pb, inoculation of arbuscular mycor-rhizal fungi significantly improved the biomass of upland rice roots （P〈0.05） but sig-nificantly reduced Pb concentration of upland rice shoots and roots （P〈0.05）; there was no significant difference in R/S between inoculation treatment and non-inocula-tion treatment. [Conclusion] This study indicated that inoculating Glomus mosseae under certain Pb concentrations could to some extent al eviate the toxic effects of Pb on Oryzal sativa L.展开更多
[Objective] This study aimed to investigate the effect of arbuscular mycor-rhizal fungi on upland rice oxidative stress induced by Cu and Pb contamination in soil. [Method] The upland rice seeds were sowed in pots, in...[Objective] This study aimed to investigate the effect of arbuscular mycor-rhizal fungi on upland rice oxidative stress induced by Cu and Pb contamination in soil. [Method] The upland rice seeds were sowed in pots, in which the soil was previously mixed with a certain amount of Glomus mosseae and 0, 100 and 200 mg/kg Cu, or 0, 300 and 600 mg/kg Pb. In the control treatment, Glomus mosseae was inactivated before mixed into the soil. Then, the physiological and chemical properties of the aboveground parts of rice plants were measured at mature stage. [Result] Compared with the control treatment （NM）, Glomus mosseae （GM） treat-ment inhibited the POD, CAT and SOD activity while increased the soluble protein content under 100 mg/kg Cu and 300 mg/kg Pb treatment, improved the POD and CAT activity and soluble protein content while decreased SOD activity under 200 mg/kg Cu. SOD and POD activity showed no significant difference between NM and GM treatment under 600 mg/kg Pb, but the CAT activity was enhanced and soluble protein content was decreased. [Conclusion] This study wil provide theoretical refer-ence for bioremediation of soil heavy metal pol ution.展开更多
[Objective] This study aimed to explore the effect of arbuscular mycorrhiza on the content of nitrogen and nitrogenous matter in amur corktree（Phellodendron amurense Rupr.）seedlings. [Method] The annual seedlings of...[Objective] This study aimed to explore the effect of arbuscular mycorrhiza on the content of nitrogen and nitrogenous matter in amur corktree（Phellodendron amurense Rupr.）seedlings. [Method] The annual seedlings of Phellodendron amurense Rupr. were inoculated with four arbuscular mycorrhiza fungi in a pot experiment to study the influences of arbuscular mycorrhiza on the content of nitrogen and nitrogenous matter in Phellodendron amurense Rupr. [Result] After inoculation with arbuscular mycorrhiza fungi, the Phellodendron amurense Rupr. seedlings developed arbuscular mycorrhiza, leading to an enhancement of photosynthetic capacity. The leaf nitrogen content of those inoculated with Glomus mosseae increased to 1.28- 1.60 times as compared with the control. The chlorophyll content and chlorophyll a/b ratio were also raised, with an increase over 25% of chlorophyll a content. In addition, IAA content in plants increased to 1.65-2.41 times; and nitrate reductase activity was also enhanced, as well as soluble protein content, 1.67-2.49 times as high as the control, which improved the nitrogen metabolic ability, and promoted the plant growth, as well as the secondary metabolic ability. [Conclusion] This study provides a theoretical basis for the application of arbuscular mycorrhiza on Phellodendron amurense Rupr.展开更多
Arbuscular mycorrhizal fungi （AMF） are essential functional microbiology in natural ecosystems. It is very important to research community composition and di- versity of AMF for achieving sustainable development of ...Arbuscular mycorrhizal fungi （AMF） are essential functional microbiology in natural ecosystems. It is very important to research community composition and di- versity of AMF for achieving sustainable development of ecosystems. The paper described several methods of researching the diversity of AMF, especially for molecular techniques, reviewed the application status of these methods in AMF research, and pointed out that the effective combination of morphological and molecular methods could better reveal the biodiversity and ecological functions of AMF in natural ecosystems.展开更多
The effects of inoculum forms (single-spore, multi-spores, or colonized root pieces) and host plants (Nicotiana tabacum L., Sorghum sudanense (Piper) Stapf, and Trifolium repens L.) on the development and inoculum pot...The effects of inoculum forms (single-spore, multi-spores, or colonized root pieces) and host plants (Nicotiana tabacum L., Sorghum sudanense (Piper) Stapf, and Trifolium repens L.) on the development and inoculum potential (IP) of the arbuscular mycorrhizal fungi (AMF) :Glo-mus macrocarpum Tul & Tul, donuis mosseae (Nicol & Gerd.) Gerdemann & Trappe, Glomus ver-siforme (Karsten) Berch, and Sclerocystis sinu/osa Gerdemann & Bakhi cultured in pots were investigated. The lag phase of treatment with 50 spores or 0.5 g (fresh weight) of colonized root pieces was 4 weeks, much shorter than that of the treatment with 1 spore (8 weeks); the value of IP (VIP) and percentage of root colonization (PRC) of the former were greater than those of the latter. Only on the early stages of colonization was there difference between the 50 spores and the 0.5 g (fresh weight) of colonized root piece inoculation treatments. The EP per plant inoculated with 0.5 g (fresh weight) of colonized root pieces of AMF was greater than that of the other two treatments except G. versiforme on Nicotiana tabacum, while the PRC of the plants inoculated with 50 spores and 0.5 g (fresh weight) of colonized root pieces of AMF was higher than that of the 1 spore inoculation after 10 weeks. Trie VIP of AMF on Trifolium repens was significantly higher than that on the other two hosts. The VIP of G. mosseae, G. versiforme, and S. sinuosa was respectively greater than that of G. macrocarpum. This suggested that different species of AMF produced different VIP of the inoculum . Nicotiana tabacum was much better than the other host plants which used to be inoculated with single spore, and to produce inocula of AMF.展开更多
The arbuscular mycorrhiza （AM） is a kind of fungi-plant associated sym- biont formed by the arbuscular mycorrhizal fungi and plants in soil. Present study was limited to the population and community level, mainly in...The arbuscular mycorrhiza （AM） is a kind of fungi-plant associated sym- biont formed by the arbuscular mycorrhizal fungi and plants in soil. Present study was limited to the population and community level, mainly in horticulture, land recla- mation, forest and environmental restoration. Research progress was also made at the cellular level and molecular level. Process and related mechanism of mycorrhizal fungi infecting root were reviewed, and future study on the mechanism of arbuscular mycorrhizal fungi infecting root should be continued.展开更多
[Objective] The aim was to study the effects of AMF on distribution of Pb in different chemical forms in rhizosphere soil of upland rice. [Method] A pot experiment was conducted to explore effects of AMF inoculation o...[Objective] The aim was to study the effects of AMF on distribution of Pb in different chemical forms in rhizosphere soil of upland rice. [Method] A pot experiment was conducted to explore effects of AMF inoculation on distribution of Pb in different forms in rhizosphere of rice (Oryzal sativa L.) with Pb in different concentrations (0, 300 and 600 mg/kg). [Result] With inoculation adopted, mycorrzhial colonization rate of upland rice under Pb pdlution root declined substantially with Pb increasing in soils (P<0.05). Compared with non-inoculation, rhizosphere pH significantly enhanced by inoculation; when Pb was at 300 mg/kg, glomalin content in soils improved significantly by inoculation; when Pb was at 600 mg/kg, glomalin content in soils declined substantially (P<0.05). In addition, inoculation significantly improved contents of Pb in exchangeable and organic forms, but lowered Pb in carbonate bound and Fe-Mn oxides bound forms (P<0.05). [Conclusion] The research indicated that AMF inoculation would change distribution of Pb in different forms in rhizosphere soils of upland rice.展开更多
[Objective] The aim was to investigated the effects of seedling-cake with AMF on resistance of pepper （Capsicum annuum L.） to bacterial wilt. [Methods] A pot experiment was conducted to evaluate the dynamics of myco...[Objective] The aim was to investigated the effects of seedling-cake with AMF on resistance of pepper （Capsicum annuum L.） to bacterial wilt. [Methods] A pot experiment was conducted to evaluate the dynamics of mycorrhizal colonization, disease index, morbidity rate, control effect and several agronomic traits of mycorrhizal seedlings after inoculation with RS in two kinds of seeding-cakes with AMF. [Results] Two kinds of seedling-cakes formed steadily mycorrhizal colonization after inoculation, which enhanced disease-resistance and decreased morbidity rate and disease index in different degrees. What’s more, the performance of self-made seedling-cakes was obviously better than that of commercial seedling-cakes. [Conclusions] Self-made seedling-cakes with AMF have superior performance on bacterial wilt resistance of pepper, which should be made use of in other crops extensively.展开更多
The effects of arbuscular mycorrhizal （AM） fungus （Glomus mosseae） and phosphorus （P） addition （100 mg/kg soil） on arsenic （As） uptake by maize plants （Zea mays L.） from an As-contaminated soil were examin...The effects of arbuscular mycorrhizal （AM） fungus （Glomus mosseae） and phosphorus （P） addition （100 mg/kg soil） on arsenic （As） uptake by maize plants （Zea mays L.） from an As-contaminated soil were examined in a glasshouse experiment. Non-mycorrhizal and zero-P addition controls were included. Plant biomass and concentrations and uptake of As, P, and other nutrients, AM colonization, root lengths, and hyphal length densities were determined. The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium. Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments, but shoot and root biomass of AM plants was depressed by P application. AM fungal inoculation decreased shoot As concentrations when no P was added, and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition, respectively. Shoot and root uptake of P, Mn, Cu, and Zn increased, but shoot Fe uptake decreased by 44.6%, with inoculation, when P was added. P addition reduced shoot P, Fe, Mn, Cu, and Zn uptake of AM plants, but increased root Fe and Mn uptake of the nonmycorrhizal ones. AM colonization therefore appeared to enhance plant tolerance to As in low P soil, and have some potential for the phytostabilization of As-contaminated soil, however, P application may introduce additional environmental risk by increasing soil As mobility.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
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
The growth and yield of peanut are negatively affected by continuous cropping.Arbuscular mycorrhizal fungi(AMF)and calcium ions(Ca^(2+))have been used to improve stress resistance in other plants,but little is known a...The growth and yield of peanut are negatively affected by continuous cropping.Arbuscular mycorrhizal fungi(AMF)and calcium ions(Ca^(2+))have been used to improve stress resistance in other plants,but little is known about their roles in peanut seedling growth under continuous cropping.This study investigated the possible roles of the AMF Glomus mosseae combined with exogenous Ca^(2+)in improving the physiological responses of peanut seedlings under continuous cropping.G.mosseae combined with exogenous Ca^(2+)can enhance plant biomass,Ca^(2+)level,and total chlorophyll content.Under exogenous Ca^(2+)application,the F_v/F_m in arbuscular mycorrhizal(AM)plant leaves was higher than that in the control plants when they were exposed to high irradiance levels.The peroxidase,superoxide dismutase,and catalase activities in AM plant leaves also reached their maximums,and accordingly,the malondialdehyde content was the lowest compared to other treatments.Additionally,root activity,and content of total phenolics and flavonoids were significantly increased in AM plant roots treated by Ca^(2+)compared to either G.mosseae inoculation or Ca^(2+)treatment alone.Transcription levels of AhCaM,AhCDPK,AhRAM1,and AhRAM2 were significantly improved in AM plant roots under exogenous Ca^(2+)treatment.This implied that exogenous Ca^(2+)might be involved in the regulation of G.mosseae colonization of peanut plants,and in turn,AM symbiosis might activate the Ca^(2+)signal transduction pathway.The combination of AMF and Ca^(2+)benefitted plant growth and development under continuous cropping,suggesting that it is a promising method to cope with the stress caused by continuous cropping.展开更多
The effect of arbuscular mycorrhiza fungi （AMF） on plant growth and nutrition utilization in upland rice and mungbean intercropping system was studied. A pot experiment was conducted in the greenhouse and AMF coloni...The effect of arbuscular mycorrhiza fungi （AMF） on plant growth and nutrition utilization in upland rice and mungbean intercropping system was studied. A pot experiment was conducted in the greenhouse and AMF colonization rates of rice and mungbean roots, plant nutrient contents, the ability of nitrogen fixation, and nutrient contents changed in the soil were analyzed. The results were obtained as follows： the rates of AMF colonization of rice and mungbean roots were reached to 14.47 and 92.2% in intercopping system, and increased by 4.11 and 11.95% compared with that of in monocropping; the nirtrogen contents of mungbean and rice were increased by 83.72 and 64.83% in shoots, and 53.76 and 41.29% in roots, respectively, while the contents of iron in shoot and root of mungbean were increased by 223.08 and 60.19%, respectively. In the intercropping system with inoculation of AMF, the biomass of mungbean increased by 288.8%. However, the biomass of rice was not significantly changed among all treatments with or without inoculation of AMF recorded. The number and dry weight of nodules were significantly increased either when mungbean was intercropped with rice or inoculated with AMF. When compared with that of monocropping without AMF inoculation, the contents of nitrogen, phosphorus and iron in nodules of intercropping mungbean with inoculation increased by 80.14, 69.54 and 39.62%, respectively. Additionally, intercropping with AMF inoculation significantly increased soil nitrogen content, but reduced soil phosphorus content. We concluded that upland rice-mungbean intercropping system and inoculation with AMF improved the nutrient uptake, the ability of nitrogen fixation and the growth of mungbean.展开更多
Roots and rhizosphere soils of Acacia auriculiformis A. Cunn. ex Benth., A. mangium Wild., Artocarpus heterophyUus Lamk. C., Dalbergia sissoo Roxb. ex A. P. D., Eucalyptus camaldulensis Dehnn., Hevea brasiliensis （Wi...Roots and rhizosphere soils of Acacia auriculiformis A. Cunn. ex Benth., A. mangium Wild., Artocarpus heterophyUus Lamk. C., Dalbergia sissoo Roxb. ex A. P. D., Eucalyptus camaldulensis Dehnn., Hevea brasiliensis （Wild. ex Juss） Muell. Arg., Swietenia macrophylla King. and Tectona grandis L. were collected from different locations of Madhupur forest area to study the biodiversity of Arbuscular Mycorrhizal （AM） fungal colonization and spore population. All the plants showed AM colonization. Out of eight selected plants, mycelial colonization was lowest in the roots of A. heterophyllus （22%） and the highest was in the roots of H. brasiliensis （78%）. Mycelial intensity was observed poor （25%-77%） and moderate （23%-57%） in all plants species and abundant （11%-40%） was in most of the plant species. Vesicular colonization was observed in five plant species. The lowest was recorded in E. camaldulensis （4%） and the highest was in H. brasiliensis （21%）. Poor （24%-56%）, moderate （16%-100%） and abundant （11%-40%） type of vesicular intensity were observed. Arbuscular colonization was observed in three plants. The highest was in A. mangium （72%） and the lowest was in S. macrophylla （17%）. Arbuscular intensity was recorded as poor （12%-44%）, moderate （22%-100%） and abundant （4%-47%）. The highest AM fungal spore population was in A. auriculiformis （714） and the lowest was in D. sissoo （102）. Five AM fungal genera were recorded. Glomus was found to be dominant. A few spores remained unidentified. Significant correlation was observed between percent coloniza- tion and spore population. The results of the present study indicate the occurrence of AM fungi and the mycotrophism of the plants of Madhupur forest area and the applicability of AM technology in the forest management of Madhupur forest.展开更多
To understand the roles of mycorrhiza in metal speciation in the rhizosphere and the impact on increasing host plant tolerance against excessive heavy metals in soil, maize(Zea mays L.) inoculated with arbuscular myco...To understand the roles of mycorrhiza in metal speciation in the rhizosphere and the impact on increasing host plant tolerance against excessive heavy metals in soil, maize(Zea mays L.) inoculated with arbuscular mycorrhizal fungus(Glomus mosseae) was cultivated in heavy metal contaminated soil. Speciations of copper, zinc and lead in the soil were analyzed with the technique of sequential extraction. The results showed that,in comparison to the bolked soil, the exchangeable copper increased from 26% to 43% in non-infected and AM-infected rhizoshpere respectively; while other speciation (organic, carbonate and Fe-Mn oxide copper) remained constant and the organic bound zinc and lead also increased but the exchangeable zinc and lead were undetectable. The organic bound copper, zinc and lead were higher by 15%, 40% and 20%, respectively, in the rhizosphere of arbuscular mycorrhiza infected maize in comparison to the non-infected maize. The results might indicate that mycorrhiza could protect its host plants from the phytotoxicity of excessive copper, zinc and lead by changing the speciation from bio-available to the non-bio-available form. The fact that copper and zinc accumulation in the roots and shoots of mycorrhia infected plants were significantly lower than those in the non-infected plants might also suggest that mycorrhiza efficiently restricted excessive copper and zinc absorptions into the host plants. Compared to the non-infected seedlings, the lead content of infected seedlings was 60% higher in shoots. This might illustrate that mycorrhiza have a different mechanism for protecting its host from excessive lead phytotoxicity by chelating lead in the shoots.展开更多
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program,China(2019QZKK0304)the National Natural Science Foundation of China(31800380 and 31761123001-1)。
文摘Fencing for grazing exclusion is regarded as a traditional and effective method for the natural restoration of degraded alpine steppe,and it effectively promotes plant growth and enhances soil carbon stocks.Arbuscular mycorrhizal fungi(AMF)are essential microorganisms in grassland that play a major role in plant-derived C translocation into the soil.However,the effects of fencing on AMF communities and their contributions to soil carbon sequestration are still unclear.In this study,alpine steppe areas with three different fencing durations(free grazing,medium-term fencing for 5-6 years and long-term fencing for more than 10 years)in the northern Tibetan Plateau were selected to explore the effects of grazing exclusion on AMF communities and their roles in soil carbon sequestration.The results showed that medium-and long-term fencing significantly increased both plant aboveground biomass and soil organic carbon(SOC)content.The AMF community composition varied significantly during different fencing durations,with a dramatic increase in the relative abundance of Glomus but a significant reduction in the relative abundance of Diversispora with longer fencing time.Medium-term fencing significantly increased AMF richness and the ShannonWiener index.Meanwhile,fencing significantly increased hyphal length density(HLD),glomalin-related soil protein(GRSP)and the proportion of macroaggregates(250-2,000μm),all of which contribute positively to SOC.Structural equation modeling revealed that fencing time positively influenced HLD and the AMF community composition,subsequently affecting T-GRSP,which was tightly correlated with SOC.Our findings suggest the potentially important contribution of AMF to SOC sequestration,so more attention should be paid to AMF during alpine steppe fencing,particularly for enhancing the efficiency of degraded grassland restoration efforts.
基金supported by the National Natural Science Foundation of China(32171970)the Chongqing Talent Program,China(cstc2022ycjh-bgzxm0073)+1 种基金the Natural Science Foundation of Chongqing,China(cstc2021jcyjcxtt X0004)the Rice Innovative Research Team of Chongqing Modern Agricultural Industrial Technology System,China(CQMAITS202301)。
文摘As a major subunit of the exocyst complex,members of the EXO70 family have mainly been shown to play roles in cell polarity and morphogenesis in Arabidopsis,but their roles in plant endosymbiosis,such as with arbuscular mycorrhizal fungi(AMF),have rarely been reported.Here,using knockout and overexpression lines,we show that OsEXO70L2,which encodes a divergent EXO70 protein in rice,controls the number of primary roots and is essential for large lateral root formation.Furthermore,the OsEXO70L2 mutant sr1 displayed rare internal AMF hyphaeand no arbuscules.We also found that AMF sporulation can occur in roots despite low colonization and that AMF colonization and sporulation are modulated by photoperiod and co-culture with clover.Finally,genes related to auxin homeostasis were found to be affected in the OsEXO70L2 knockout or overexpression lines,suggesting that auxin is at least partly responsible for the phenotypes.This study provides new perspectives on the role of the exocyst complex during root development and AM in rice.
基金supported by 2024 Guizhou Basic Research Plan(Natural Science)Project,China(Foundation of Guizhou science cooperation-ZK[2024]General 490)the National Natural Science Foundation of China(No.31560107).
文摘The mutualistic symbiotic system formed by clumping arbuscular mycorrhizal fungi(AMF)and plants can remediate heavy metal-contaminated soils.However,the specific mechanisms underlying the interaction between AMF and inter-root microbial communities,particularly their impact on organic phosphorus(P)cycling,remain unclear.This study investigated the gene regulation processes involved in inter-root soil phosphorus cycling in wetland plants,specifically Iris tectorum,following inoculation with AMF under varying concentrations of chromium(Cr)stress.Through macro-genome sequencing,we analyzed the composition and structure of the inter-root soil microbial community associated with Iris tectorum under greenhouse pot conditions.The results demonstrated significant changes in the diversity and composition of the inter-root soil microbial community following AMF inoculation,with Proteobacteria,Actinobacteria,Chloroflexi,Acidobacteria,and Bacteroidetes being the dominant taxa.Under Cr stress,species and gene co-occurrence network analysis revealed that AMF promoted the transformation process of organic phosphorus mineralization and facilitated inorganic phosphorus uptake.Additionally,network analysis of functional genes indicated strong aggregation of(pstS,pstA,pstC,TC.PIT,phoR,pp-gppA)genes,which collectively enhanced phosphorus uptake by plants.These findings shed light on the inter-root soil phosphorus cycling process during the co-remediation of Cr-contaminated soil by AMF-Iris tectorum symbiosis,providing valuable theoretical support for the application of AMF-wetland plant symbiosis systems to remediate heavy metal-contaminated soil.
基金Supported by National Science and Technology Support Project(2006BAD07B05)Cooperation Project of Institute of Vegetables and Flowers,Chinese Academy of Agricultural Sciences,with Bei-jing Daxing District(2009-2011)~~
文摘[Objective] The purpose was to study the effects of different arbuscular mycorrhizal fungi strains（AMF）on the mineral nutrition and antioxidant enzymes of Chrysanthemum morifolium.[Method] The pot experiment was conducted in the greenhouse,C.morifolium ＇Jinba＇ was inoculated with five kinds of AMF,N,P,K,malondial dehyde（MDA）content,as well as the superoxide dismutase（SOD）,peroxidase（POD） and catalase（CAT） activity in roots,leaves and petals of C.morifolium were measured at seedling and flowering stages.[Result] The G.i,G.e and G.m treatments could promote mineral nutrient absorption,increase N,P,K content in roots,leaves and petals of C.morifolium compared with the control without inoculation.The G.d、G.e and G.m treatments could significantly reduce MDA content in roots and petals,thus alleviating membrane permeability and lipid peroxidation.The G.i treatments could also improve the SOD,POD and CAT activities of C.morifolium,thereby increasing the capability of scavenging oxygen free radicals.[Conclusion] According to the comprehensive analysis,G.i was screened out as the best strain to improve mineral nutrition and antioxidant enzyme activities of C.morifolium.
基金This paper was supported by the Heilongjiang Province Foundation for Distinguished Youth Scholars (JC-02-11)
文摘Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi （AMF）, Acaulospora mellea, Glomus diaphanum and Sclerocystis sinuosa.. The height, biomass, and absorptions of nitrogen and phosphorus of C. acuminata seedlings inoculated with AMF were investigated. The results showed that the formation of AM promoted the height growth and biomass accumulation of seedlings significantly and improved the absorption of phosphorus in seedlings. The height and biomass of mycorrhizal seedlings were 1.2 and 1.6 times higher than those of the non-mycorrhizal seedlings. The absorption of nitrogen was less influenced by the formation of AM. The nitrogen content in mycorrhizal seedling was equal to that of non-mycorrhizal seedlings. Compared with non-mycorrhizal seedlings, the nitrogen content of mycorrhizal seedlings inoculated with A. mellea changed considerably in the root, stem and leaves. The difference in nitrogen content was not significant between mycorrhizal seedlings inoculated with G. diaphanum and S. sinuosa. The AM formation stimulated the absorption of phosphorus, especially in roots, and also changed the allocation of nitrogen and phosphorus in different organs of seedlings. Compared with non-mycorrhizal seedlings, the ratio of nitrogen and phosphorus in mycorrhizal roots increased, but reduced in stem and leaves.
基金Supported by National Natural Science Foundation of China(81072989,40901149)Project for Promotion and Development of Private Education-Teaching and Educational Reform-Beijing City University "Construction of New Discipline-Water Supply and Drainage Engineering"~~
文摘[Objective] This study aimed to investigate the effects of arbuscular mycor-rhizal fungi （AMF） on growth of upland rice under soil Pb contamination. [Method] Using potting method, the effects of Glomus mosseae on the growth of Oryzal sati-va L. under different soil Pb concentrations （0, 300, 600 mg/kg） were investigated. [Result] According to the results, the mycorrhizal colonization rate of upland rice in-oculated with Glomus mosseae was significantly reduced （P〈0.05） with the increase of Pb concentration in soil. Compared with non-inoculation treatment, inoculation of arbuscular mycorrhizal fungi significantly improved the biomass of upland rice and Pb concentration of upland rice roots with addition of 300 mg/kg Pb but significantly reduced Pb concentration of upland rice shoots, which was consistent with the re-duced R/S （P〈0.05）; with addition of 600 mg/kg Pb, inoculation of arbuscular mycor-rhizal fungi significantly improved the biomass of upland rice roots （P〈0.05） but sig-nificantly reduced Pb concentration of upland rice shoots and roots （P〈0.05）; there was no significant difference in R/S between inoculation treatment and non-inocula-tion treatment. [Conclusion] This study indicated that inoculating Glomus mosseae under certain Pb concentrations could to some extent al eviate the toxic effects of Pb on Oryzal sativa L.
基金Supported by National Natural Science Foundation of China(41101246)Private Education Development Project(892-34)~~
文摘[Objective] This study aimed to investigate the effect of arbuscular mycor-rhizal fungi on upland rice oxidative stress induced by Cu and Pb contamination in soil. [Method] The upland rice seeds were sowed in pots, in which the soil was previously mixed with a certain amount of Glomus mosseae and 0, 100 and 200 mg/kg Cu, or 0, 300 and 600 mg/kg Pb. In the control treatment, Glomus mosseae was inactivated before mixed into the soil. Then, the physiological and chemical properties of the aboveground parts of rice plants were measured at mature stage. [Result] Compared with the control treatment （NM）, Glomus mosseae （GM） treat-ment inhibited the POD, CAT and SOD activity while increased the soluble protein content under 100 mg/kg Cu and 300 mg/kg Pb treatment, improved the POD and CAT activity and soluble protein content while decreased SOD activity under 200 mg/kg Cu. SOD and POD activity showed no significant difference between NM and GM treatment under 600 mg/kg Pb, but the CAT activity was enhanced and soluble protein content was decreased. [Conclusion] This study wil provide theoretical refer-ence for bioremediation of soil heavy metal pol ution.
文摘[Objective] This study aimed to explore the effect of arbuscular mycorrhiza on the content of nitrogen and nitrogenous matter in amur corktree（Phellodendron amurense Rupr.）seedlings. [Method] The annual seedlings of Phellodendron amurense Rupr. were inoculated with four arbuscular mycorrhiza fungi in a pot experiment to study the influences of arbuscular mycorrhiza on the content of nitrogen and nitrogenous matter in Phellodendron amurense Rupr. [Result] After inoculation with arbuscular mycorrhiza fungi, the Phellodendron amurense Rupr. seedlings developed arbuscular mycorrhiza, leading to an enhancement of photosynthetic capacity. The leaf nitrogen content of those inoculated with Glomus mosseae increased to 1.28- 1.60 times as compared with the control. The chlorophyll content and chlorophyll a/b ratio were also raised, with an increase over 25% of chlorophyll a content. In addition, IAA content in plants increased to 1.65-2.41 times; and nitrate reductase activity was also enhanced, as well as soluble protein content, 1.67-2.49 times as high as the control, which improved the nitrogen metabolic ability, and promoted the plant growth, as well as the secondary metabolic ability. [Conclusion] This study provides a theoretical basis for the application of arbuscular mycorrhiza on Phellodendron amurense Rupr.
基金Supported by National Natural Science Foundation of China (30900963)Natural Science Foundation of Yunnan Province (2009ZC072M)Scientific Research Pogram of Yunnan Provincial Educaition Department (09Z0038)~~
文摘Arbuscular mycorrhizal fungi （AMF） are essential functional microbiology in natural ecosystems. It is very important to research community composition and di- versity of AMF for achieving sustainable development of ecosystems. The paper described several methods of researching the diversity of AMF, especially for molecular techniques, reviewed the application status of these methods in AMF research, and pointed out that the effective combination of morphological and molecular methods could better reveal the biodiversity and ecological functions of AMF in natural ecosystems.
基金Supported by International foundation for Science (IFS)National Natural Science Foundation of China.
文摘The effects of inoculum forms (single-spore, multi-spores, or colonized root pieces) and host plants (Nicotiana tabacum L., Sorghum sudanense (Piper) Stapf, and Trifolium repens L.) on the development and inoculum potential (IP) of the arbuscular mycorrhizal fungi (AMF) :Glo-mus macrocarpum Tul & Tul, donuis mosseae (Nicol & Gerd.) Gerdemann & Trappe, Glomus ver-siforme (Karsten) Berch, and Sclerocystis sinu/osa Gerdemann & Bakhi cultured in pots were investigated. The lag phase of treatment with 50 spores or 0.5 g (fresh weight) of colonized root pieces was 4 weeks, much shorter than that of the treatment with 1 spore (8 weeks); the value of IP (VIP) and percentage of root colonization (PRC) of the former were greater than those of the latter. Only on the early stages of colonization was there difference between the 50 spores and the 0.5 g (fresh weight) of colonized root piece inoculation treatments. The EP per plant inoculated with 0.5 g (fresh weight) of colonized root pieces of AMF was greater than that of the other two treatments except G. versiforme on Nicotiana tabacum, while the PRC of the plants inoculated with 50 spores and 0.5 g (fresh weight) of colonized root pieces of AMF was higher than that of the 1 spore inoculation after 10 weeks. Trie VIP of AMF on Trifolium repens was significantly higher than that on the other two hosts. The VIP of G. mosseae, G. versiforme, and S. sinuosa was respectively greater than that of G. macrocarpum. This suggested that different species of AMF produced different VIP of the inoculum . Nicotiana tabacum was much better than the other host plants which used to be inoculated with single spore, and to produce inocula of AMF.
基金Supported by the National Natural Science Foundation of China(41401496)the Foundation for Fostering Talents of the Xi’an University of Technology(201306)the Startup Foundation for Doctors of Xi’an University of Technology(2014QDJ061)~~
文摘The arbuscular mycorrhiza （AM） is a kind of fungi-plant associated sym- biont formed by the arbuscular mycorrhizal fungi and plants in soil. Present study was limited to the population and community level, mainly in horticulture, land recla- mation, forest and environmental restoration. Research progress was also made at the cellular level and molecular level. Process and related mechanism of mycorrhizal fungi infecting root were reviewed, and future study on the mechanism of arbuscular mycorrhizal fungi infecting root should be continued.
文摘[Objective] The aim was to study the effects of AMF on distribution of Pb in different chemical forms in rhizosphere soil of upland rice. [Method] A pot experiment was conducted to explore effects of AMF inoculation on distribution of Pb in different forms in rhizosphere of rice (Oryzal sativa L.) with Pb in different concentrations (0, 300 and 600 mg/kg). [Result] With inoculation adopted, mycorrzhial colonization rate of upland rice under Pb pdlution root declined substantially with Pb increasing in soils (P<0.05). Compared with non-inoculation, rhizosphere pH significantly enhanced by inoculation; when Pb was at 300 mg/kg, glomalin content in soils improved significantly by inoculation; when Pb was at 600 mg/kg, glomalin content in soils declined substantially (P<0.05). In addition, inoculation significantly improved contents of Pb in exchangeable and organic forms, but lowered Pb in carbonate bound and Fe-Mn oxides bound forms (P<0.05). [Conclusion] The research indicated that AMF inoculation would change distribution of Pb in different forms in rhizosphere soils of upland rice.
基金Supported by Hunan Natural Science Foundation(11JJ5015)Department of Science and Technology of Hunan Province(2011FJ3050)~~
文摘[Objective] The aim was to investigated the effects of seedling-cake with AMF on resistance of pepper （Capsicum annuum L.） to bacterial wilt. [Methods] A pot experiment was conducted to evaluate the dynamics of mycorrhizal colonization, disease index, morbidity rate, control effect and several agronomic traits of mycorrhizal seedlings after inoculation with RS in two kinds of seeding-cakes with AMF. [Results] Two kinds of seedling-cakes formed steadily mycorrhizal colonization after inoculation, which enhanced disease-resistance and decreased morbidity rate and disease index in different degrees. What’s more, the performance of self-made seedling-cakes was obviously better than that of commercial seedling-cakes. [Conclusions] Self-made seedling-cakes with AMF have superior performance on bacterial wilt resistance of pepper, which should be made use of in other crops extensively.
基金Project supported by the National Natural Science Foundation of China (No.40401031)
文摘The effects of arbuscular mycorrhizal （AM） fungus （Glomus mosseae） and phosphorus （P） addition （100 mg/kg soil） on arsenic （As） uptake by maize plants （Zea mays L.） from an As-contaminated soil were examined in a glasshouse experiment. Non-mycorrhizal and zero-P addition controls were included. Plant biomass and concentrations and uptake of As, P, and other nutrients, AM colonization, root lengths, and hyphal length densities were determined. The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium. Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments, but shoot and root biomass of AM plants was depressed by P application. AM fungal inoculation decreased shoot As concentrations when no P was added, and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition, respectively. Shoot and root uptake of P, Mn, Cu, and Zn increased, but shoot Fe uptake decreased by 44.6%, with inoculation, when P was added. P addition reduced shoot P, Fe, Mn, Cu, and Zn uptake of AM plants, but increased root Fe and Mn uptake of the nonmycorrhizal ones. AM colonization therefore appeared to enhance plant tolerance to As in low P soil, and have some potential for the phytostabilization of As-contaminated soil, however, P application may introduce additional environmental risk by increasing soil As mobility.
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 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.
基金supported by the National Natural Science Foundation of China (31601261, 31601252, 31571581 and 31571605)the China Postdoctoral Science Foundation (2016M592236)
文摘The growth and yield of peanut are negatively affected by continuous cropping.Arbuscular mycorrhizal fungi(AMF)and calcium ions(Ca^(2+))have been used to improve stress resistance in other plants,but little is known about their roles in peanut seedling growth under continuous cropping.This study investigated the possible roles of the AMF Glomus mosseae combined with exogenous Ca^(2+)in improving the physiological responses of peanut seedlings under continuous cropping.G.mosseae combined with exogenous Ca^(2+)can enhance plant biomass,Ca^(2+)level,and total chlorophyll content.Under exogenous Ca^(2+)application,the F_v/F_m in arbuscular mycorrhizal(AM)plant leaves was higher than that in the control plants when they were exposed to high irradiance levels.The peroxidase,superoxide dismutase,and catalase activities in AM plant leaves also reached their maximums,and accordingly,the malondialdehyde content was the lowest compared to other treatments.Additionally,root activity,and content of total phenolics and flavonoids were significantly increased in AM plant roots treated by Ca^(2+)compared to either G.mosseae inoculation or Ca^(2+)treatment alone.Transcription levels of AhCaM,AhCDPK,AhRAM1,and AhRAM2 were significantly improved in AM plant roots under exogenous Ca^(2+)treatment.This implied that exogenous Ca^(2+)might be involved in the regulation of G.mosseae colonization of peanut plants,and in turn,AM symbiosis might activate the Ca^(2+)signal transduction pathway.The combination of AMF and Ca^(2+)benefitted plant growth and development under continuous cropping,suggesting that it is a promising method to cope with the stress caused by continuous cropping.
基金supported by the National 973 Programof China (2007CB109304)
文摘The effect of arbuscular mycorrhiza fungi （AMF） on plant growth and nutrition utilization in upland rice and mungbean intercropping system was studied. A pot experiment was conducted in the greenhouse and AMF colonization rates of rice and mungbean roots, plant nutrient contents, the ability of nitrogen fixation, and nutrient contents changed in the soil were analyzed. The results were obtained as follows： the rates of AMF colonization of rice and mungbean roots were reached to 14.47 and 92.2% in intercopping system, and increased by 4.11 and 11.95% compared with that of in monocropping; the nirtrogen contents of mungbean and rice were increased by 83.72 and 64.83% in shoots, and 53.76 and 41.29% in roots, respectively, while the contents of iron in shoot and root of mungbean were increased by 223.08 and 60.19%, respectively. In the intercropping system with inoculation of AMF, the biomass of mungbean increased by 288.8%. However, the biomass of rice was not significantly changed among all treatments with or without inoculation of AMF recorded. The number and dry weight of nodules were significantly increased either when mungbean was intercropped with rice or inoculated with AMF. When compared with that of monocropping without AMF inoculation, the contents of nitrogen, phosphorus and iron in nodules of intercropping mungbean with inoculation increased by 80.14, 69.54 and 39.62%, respectively. Additionally, intercropping with AMF inoculation significantly increased soil nitrogen content, but reduced soil phosphorus content. We concluded that upland rice-mungbean intercropping system and inoculation with AMF improved the nutrient uptake, the ability of nitrogen fixation and the growth of mungbean.
文摘Roots and rhizosphere soils of Acacia auriculiformis A. Cunn. ex Benth., A. mangium Wild., Artocarpus heterophyUus Lamk. C., Dalbergia sissoo Roxb. ex A. P. D., Eucalyptus camaldulensis Dehnn., Hevea brasiliensis （Wild. ex Juss） Muell. Arg., Swietenia macrophylla King. and Tectona grandis L. were collected from different locations of Madhupur forest area to study the biodiversity of Arbuscular Mycorrhizal （AM） fungal colonization and spore population. All the plants showed AM colonization. Out of eight selected plants, mycelial colonization was lowest in the roots of A. heterophyllus （22%） and the highest was in the roots of H. brasiliensis （78%）. Mycelial intensity was observed poor （25%-77%） and moderate （23%-57%） in all plants species and abundant （11%-40%） was in most of the plant species. Vesicular colonization was observed in five plant species. The lowest was recorded in E. camaldulensis （4%） and the highest was in H. brasiliensis （21%）. Poor （24%-56%）, moderate （16%-100%） and abundant （11%-40%） type of vesicular intensity were observed. Arbuscular colonization was observed in three plants. The highest was in A. mangium （72%） and the lowest was in S. macrophylla （17%）. Arbuscular intensity was recorded as poor （12%-44%）, moderate （22%-100%） and abundant （4%-47%）. The highest AM fungal spore population was in A. auriculiformis （714） and the lowest was in D. sissoo （102）. Five AM fungal genera were recorded. Glomus was found to be dominant. A few spores remained unidentified. Significant correlation was observed between percent coloniza- tion and spore population. The results of the present study indicate the occurrence of AM fungi and the mycotrophism of the plants of Madhupur forest area and the applicability of AM technology in the forest management of Madhupur forest.
文摘To understand the roles of mycorrhiza in metal speciation in the rhizosphere and the impact on increasing host plant tolerance against excessive heavy metals in soil, maize(Zea mays L.) inoculated with arbuscular mycorrhizal fungus(Glomus mosseae) was cultivated in heavy metal contaminated soil. Speciations of copper, zinc and lead in the soil were analyzed with the technique of sequential extraction. The results showed that,in comparison to the bolked soil, the exchangeable copper increased from 26% to 43% in non-infected and AM-infected rhizoshpere respectively; while other speciation (organic, carbonate and Fe-Mn oxide copper) remained constant and the organic bound zinc and lead also increased but the exchangeable zinc and lead were undetectable. The organic bound copper, zinc and lead were higher by 15%, 40% and 20%, respectively, in the rhizosphere of arbuscular mycorrhiza infected maize in comparison to the non-infected maize. The results might indicate that mycorrhiza could protect its host plants from the phytotoxicity of excessive copper, zinc and lead by changing the speciation from bio-available to the non-bio-available form. The fact that copper and zinc accumulation in the roots and shoots of mycorrhia infected plants were significantly lower than those in the non-infected plants might also suggest that mycorrhiza efficiently restricted excessive copper and zinc absorptions into the host plants. Compared to the non-infected seedlings, the lead content of infected seedlings was 60% higher in shoots. This might illustrate that mycorrhiza have a different mechanism for protecting its host from excessive lead phytotoxicity by chelating lead in the shoots.
