Mining activities have caused significant land degradation globally,emphasizing the need for effective restoration.Microbial inoculants offer a promising solution for sustainable remediation by enhancing soil nutrient...Mining activities have caused significant land degradation globally,emphasizing the need for effective restoration.Microbial inoculants offer a promising solution for sustainable remediation by enhancing soil nutrients,enzyme activities,and microbial communities to support plant growth.However,the mechanisms by which inoculants influence soil microbes and their relationship with plant growth require further investigation.Metagenomic sequencing was employed for this study,based on a one-year greenhouse experiment,to elucidate the effects of Bacillus thuringiensis NL-11 on the microbial functions of abandoned mine soils.Our findings revealed that the application of microbial inoculants significantly enhanced the soil total carbon(TC),total sulfur(TS),organic carbon(SOC),available phosphorus(AP),ammonium(NH4+),urease,arylsulfatase,phosphatase,β-1,4-glucosidase(BG),β-1,4-N-acetylglucosaminidase(NAG).Moreover,this led to substantial improvements in plant height,as well as aboveground and belowground biomass.Microbial inoculants impacted functional gene structures without altering diversity.The normalized abundance of genes related to the degradation of carbon and nitrogen,methane metabolism,and nitrogen fixation were observed to increase,as well as the functional genes related to phosphorus cycling.Significant correlations were found between nutrient cycling gene abundance and plant biomass.Partial Least Squares Path Model analysis showed that microbial inoculants not only directly influenced plant biomass but also indirectly affected the plant biomass through C cycle modifications.This study highlights the role of microbial inoculants in promoting plant growth and soil restoration by improving soil properties and enhancing normalized abundance of nutrient cycling gene,making them essential for the recovery of abandoned mine sites.展开更多
Peanuts are important oilseed legume crops that are susceptible to contamination by Aspergillus flavus in soil,leading to serious economic losses.Previously,our research team developed the Aspergillus-Rihizobia coupli...Peanuts are important oilseed legume crops that are susceptible to contamination by Aspergillus flavus in soil,leading to serious economic losses.Previously,our research team developed the Aspergillus-Rihizobia coupling(ARC)microbial inoculants and found it can reduce A.flavus abundance in the soil and promote efficient nodulation in peanuts.However,the impact of ARC microbial inoculants on different resistant varieties of A.flavus remains unclear.In this study,we screened peanut varieties that were resistant and susceptible to A.flavus and evaluated their nodulation ability and growth performance after ARC microbial inoculants treatment in the field.The results demonstrated that the nodule number and nitrogenase activity of both varieties significantly increased after ARC microbial inoculants treatment,with the highly susceptible variety AH24 showing a greater increase.For photosynthetic parameters,both varieties also increased after ARC microbial inoculants treatment,but the increase was greater in the moderately resistant variety AH1 than in the highly susceptible variety AH24.Finally,we found that the yield and yield-related traits of the moderately resistant variety AH1 were better than those of the highly susceptible variety AH24.After ARC microbial inoculants treatment,the yield traits of both peanut varieties still increased significantly,but the degree of increase of the moderately resistant variety AH1 was smaller than that of the highly susceptible variety AH24.In addition,the abundance of A.flavus in the rhizosphere soil of the two varieties significantly decreased after ARC microbial inoculants treatment,with no significant difference between the varieties.These results indicated that ARC microbial inoculants exert differential effects on the nodulation and growth of different resistant peanut varieties and have a better effect on highly susceptible varieties.These results provide a solid theoretical basis for the efficient use of ARC microbial inoculants in the field of peanuts in the future.展开更多
Synthetic fertilizers are widely used to address the urgent challenge of ensuring food supplies for a growing world population in the context of climate change. However, their industrial production and use in agricult...Synthetic fertilizers are widely used to address the urgent challenge of ensuring food supplies for a growing world population in the context of climate change. However, their industrial production and use in agriculture have a negative impact on the environment and consequently on human health. While chemical fertilizers may not have to be abandoned in agricultural production systems, limiting their use could help to make agriculture sustainable and resilient to climate change. In Senegal, the level of mineral fertilizers used in market gardening has become alarming in the Niayes area. As a result, microbial biotechnologies have been promoted for biofertilizer production of common bean (Phaseolus vulgaris L.) cultivation. Rhizobial inoculums have thus been used to reduce the rate of chemical nitrogen fertilizers being applied in cropping systems. Several investigations in the laboratory, on experimental stations and in the field have shown a possibility of a significant reduction in the use of nitrogen fertilizers in common bean production. Conventional mineral fertilization use can be reduced from over 120 kg N/ha to 20 kg N/ha. This contributes both to a very significant reduction in the application rate with the same level of yield and to an improvement in the standard of living. In addition, the environmental impact of using chemical fertilizers can be mitigated. This study is a contribution to the promotion of biofertilizers adoption in agricultural systems.展开更多
Although the application of straw decomposing microorganism inoculants(SDMI)can accelerate straw decomposition,the underlying mechanisms affecting soil organic carbon(SOC)under different scenarios remain unclear.We co...Although the application of straw decomposing microorganism inoculants(SDMI)can accelerate straw decomposition,the underlying mechanisms affecting soil organic carbon(SOC)under different scenarios remain unclear.We conducted a meta-analysis using 226 observations from 86 studies on SOC changes under straw return with or without SDMI applications.Overall,our results indicated that straw with SDMI application increased the SOC stock by 1.51%at an initial carbon-to-nitrogen ratio(ICNR)>25(P<0.05),while the effect of ICNR≤25was insignificant.In particular,at ICNR>25,application of SDMI-treated straw increased SOC stocks in northern temperate continental areas(NTC)higher than in subtropical monsoon regions(STM).Furthermore,the straw with SDMI application increased higher SOC stocks in soils with pH>7.5 than those with pH≤7.5.In terms of agricultural management practices,SOC stocks were significantly higher in straw buried(SB),the experimental duration of straw return(EDSR)≥1 year,the straw return amount(SRA)>6,000 kg ha^(–1),and the SDMI application rate(SDMIR)>30 kg ha^(–1)conditions.The effect of straw with SDMI on SOC stocks under straw burying(SB)was significantly higher than that under straw mulching(SM)at ICNR≤25.At ICNR>25,EDSR,SDMIR,and the mean annual precipitation(MAP)were the main drivers of the effect of SDMI addition to straw on SOC stocks.Straw with SDMI induced SOC stock increases which increased with EDSR and decreased with increasing MAP.These findings provide a scientific basis for decision-makers and stakeholders to improve soil C management via the application of SDMI-amended straw at both regional and large scales.展开更多
The Agrobacterium-mediated transient expression system with conventional binary vectors is well established in tobacco leaves,while the same system applied to tomato leaflets has relatively low expression efficiency.H...The Agrobacterium-mediated transient expression system with conventional binary vectors is well established in tobacco leaves,while the same system applied to tomato leaflets has relatively low expression efficiency.However,impacts of the leaf age,inoculation method and incubation condition after Agrobacterium infiltration on transient protein expression efficiency are seldom investigated.In this study,we optimize Agrobacterium-mediated transient expression system using conventional binary vectors to achieve the high efficiency of target gene expression in tomato leaflets.We transiently express GFP and a nucleus-localized gene SlUVI4 fused with GFP in detached 10-,20-,and 30-day-old leaflets.The cutting points of leaflets are embedded in MS medium after the Agrobacterium-mediated vacuum infiltration,and all leaflets are kept in the dark before use.The 10-and 30-day-old leaflets have more damage than 20-day-old leaflets after the infiltration.展开更多
Microbial growth causes lamb spoilage.This study explored the spoilage ability of Latilactobacillus sakei,Serratia proteamaculans and Hafnia proteus in vacuum-packed raw lamb,including growth ability,degradation of pr...Microbial growth causes lamb spoilage.This study explored the spoilage ability of Latilactobacillus sakei,Serratia proteamaculans and Hafnia proteus in vacuum-packed raw lamb,including growth ability,degradation of protein and lipid,and change of volatile organic compounds(VOCs)profile,meanwhile screened the key VOCs produced by the targeted strains with meat background excluding,finally confirmed the volatile spoilage marker of vacuum-packaged lamb by comparing with our previous work.The results showed that L.sakei,S.proteamaculans and H.proteus had excellent growth ability.L.sakei inoculated group significantly reduced the pH value,showed higher trichloroacetic acid-soluble peptides content,and excellently degraded sarcoplasmic and myofibrillar proteins.About free amino acids,L.sakei significantly degraded serine,arginine and aspartic acid,while S.proteamaculans and H.proteus significantly degraded serine and lysine.In addition,L.sakei had the strongest effect on promoting free fatty acid production,followed by S.proteamaculans and finally H.proteus.Evaluating from various indicators,the co-culture of the three strains did not have any effect.The key volatiles produced by L.sakei were 1-hexanol,acetic acid and hexanoic acid,S.proteamaculans produced 1-hexanol and acetoin,and H.proteus produced 1-hexanol,acetic acid and acetoin.In the end,1-hexanol,hexanoic acid and acetoin were proven to be spoilage markers for vacuum-packaged and chilled lamb.This study can provide fundamental information for inhibiting and rapid identification of spoilage in vacuum-packaged lamb.展开更多
Improving the high-temperature performance of Inconel 718(IN718)alloys manufactured via laser powder bed fusion(LPBF)has been the most concerned issue in the industry.In this study,the effects of Ti_(2)AlC inoculants ...Improving the high-temperature performance of Inconel 718(IN718)alloys manufactured via laser powder bed fusion(LPBF)has been the most concerned issue in the industry.In this study,the effects of Ti_(2)AlC inoculants on microstructures and high-temperature mechanical properties of the as-built IN718 composites were investigated.According to statistical results of relative density and unmelted particle area in as-built alloys,the optimal energy of 112 J/mm^(3)was determined.It was observed that the precipitation of the MC carbide was significantly enhanced with the addition of Ti_(2)AlC,restricting the precipitation of the Laves phase.The MC particles were uniformly distributed along the subgrain boundaries,which contributed to the dispersion strengthening.Meanwhile,the MC particles served as nucleation sites for heterogeneous nucleation during the solidification process,facilitating the refinement of columnar and cellular grains.The simulated Scheil-Gulliver curves showed that the precipitation sequence of phases did not change with Ti_(2)AlC inoculants.The as-built 1%Ti_(2)AlC/IN718 sample demonstrated an ultimate tensile strength of 998.78 MPa and an elongation of 18.04%at 650℃,revealing a markedly improved mechanical performance compared with the LPBF-manufactured IN718 alloys.The high-temperature tensile strength of 1%Ti_(2)AlC/IN718 sample increased to 1197.99 MPa by heat treatment.It was suggested that dislocation strengthening and ordered strengthening were two most important reinforcement mechanisms.展开更多
The combined effects of direct current pulsed magnetic field （DC-PMF） and inoculation on pure aluminum were investigated, the grain refinement behavior of DC-PMF and inoculation was discussed. The experimental resul...The combined effects of direct current pulsed magnetic field （DC-PMF） and inoculation on pure aluminum were investigated, the grain refinement behavior of DC-PMF and inoculation was discussed. The experimental results indicate that the solidification micro structure of pure aluminum can be greatly refined under DC-PMF. Refinement of pure aluminum is attributed to electromagnetic undercooling and forced convection caused by DC-PMF. With single DC-PMF, the grain size in the equiaxed zone is uneven. However, under DC-PMF, by adding 0.05% （mass fraction） Al5Ti-B, the grain size of the sample is smaller, and the size distribution is more uniform than that of single DC-PMF. Furthermore, under the combination of DC-PMF and inoculation, with the increase of output current, the grain size is further reduced. When the output current increases to 100 A, the average grain size can decrease to 113 μn.展开更多
[Objective] This study aimed to explore the inoculation effects of Dendrobium officinale mycorrhizal fungi on their plantlets. [Method] Endophytic strains Tj1, Tj2 and Tj3 were obtained by isolation and purification f...[Objective] This study aimed to explore the inoculation effects of Dendrobium officinale mycorrhizal fungi on their plantlets. [Method] Endophytic strains Tj1, Tj2 and Tj3 were obtained by isolation and purification from mycorrhiza of wild Dendrobium officinale and inoculated on the root system of Dendrobium officinale for inoculation test. [Result] Under tissue-culture conditions, at early stage, Tj1 strain hadn＇t shown promotion effect on Dendrobium officinale, Tj2 strain had shown relatively strong promotion effects, and Tj3 strain had promoted the growth of roots; at late stage, Tj1 strain had shown relatively strong promotion effects, Tj2 strain had shown the best inoculation effects and the strongest promotion effects, while Tj3 strain had caused root and seedling rot problems of the plantlets; under outdoor conditions, after inoculation with Tj2 strain, the number of leaves and lateral buds were increased, the growth of lateral root and the increase of plant height were significant, the leaves of Dendrobium officinale plantlets were large and dark green and an obvious root enlargement phenomenon was observed. [Conclusion] The two inoculation methods both indicate that Tj2 strain has relatively strong promotion effects on the growth of Dendrobium officinale roots and shoots, the increase of plant number and plant height, and the germination of new shoots and roots, which proved the effective establishment of symbiotic relationship between Tj2 strain and Dendrobium officinale. Therefore, T2 strain has practical application values on the successful cultivation of Dendrobium officinale plantlets.展开更多
[Objective]The aim of this study was to identify transient expression of movement protein （MP） gene in Nicotinana benthaminana rapidly and further investigate the function of this exogenous gene. [Method]The movemen...[Objective]The aim of this study was to identify transient expression of movement protein （MP） gene in Nicotinana benthaminana rapidly and further investigate the function of this exogenous gene. [Method]The movement protein gene of barley yellow dwarf virus （BYDV） was cloned into potato virus X （PVX） viral vector of pGR107,and PVX-recombinant vector was obtained. After electroporation of Agrobacterium tumefaciens,PVX was inoculated into the lower leaves of tobacco by Agrobacterium infiltration assay to observe the infection of virus on tobacco. [Result]After infection for 7 days,upper non-inoculated leaves of tobacco infected by the PVX-recombinant vector showed the virus infection symptoms,while the control group had no viral infection phenomenon. Daily follow-up observations for two groups revealed that tobacco infected by PVX-recombinant vector had severe symptoms of virus infection and curling leaves,or even led to necrosis both in infiltrated and systemic leaves in late period. However,tobacco infected by PVX vector had only slight symptoms of virus infection and could recover from infection. RT-PCR of the infected tobacco indicated that exogenous gene BYDV-MP had a normal transcription and expression in tobacco. [Conclusion]As a determinant factor for viral disease,BYDV-MP promotes the systemic infection rate of PVX and its symptom. In addition,it is feasible to express exogenous MP gene in Nicotiana benthaminan via PVX expression vector.展开更多
Mg-3%Al alloy was modified by combining Ca addition with carbon inoculation. The effects of Fe addition and addition sequence on the grain refinement were investigated. A higher grain refining efficiency could be obta...Mg-3%Al alloy was modified by combining Ca addition with carbon inoculation. The effects of Fe addition and addition sequence on the grain refinement were investigated. A higher grain refining efficiency could be obtained for the Mg-Al alloy modified by combining Ca addition with carbon inoculation. Fe addition and addition sequence had no obvious effect on the grain refinement. Ca addition could effectively avoid grain-coarsening resulting from Fe in the carbon-inoculated Mg-Al alloy. The Al-C-O particles, actually being Al4C3, should act as potent substrates for a-Mg grains in the sample treated by combining Ca addition with carbon inoculation. However, the duplex-phase particles of AI4C3 coated on Al-Fe or Al-C-Fe should be the potent substrates for a-Mg grains if Fe existed in the Mg-Al melt. Ca addition can contribute to the formation of the particles of Al4C3 coated on Al-Fe or Al-C-Fe, regardless of the Fe addition sequence. The poisoning effect of Fe was effectively inhibited in the carbon-inoculated of Mg-Al alloy due to Ca addition, namely, Ca has a poisoning-free effect.展开更多
To fit the special needs of gray cast iron as a new engineering material,i.e.,higher σ b and lower HB,or lower σ b and higher HB,using the method of heat analyzing and polyparameters analytic figures,the ...To fit the special needs of gray cast iron as a new engineering material,i.e.,higher σ b and lower HB,or lower σ b and higher HB,using the method of heat analyzing and polyparameters analytic figures,the synthetic rules of carbon saturation degree,inoculation degree and mechanical properties can be exposed.The result shows that,according to the needs of the part′s mechanical properties,referring to the synthetic rules of gray cast iron,the corresponding technological measure and composition proportion can be defined,by which we will get the exact mechanical properties that could achieve the result expected completely.Thus,the casting for gray cast iron might be 'designed'from'selected'.展开更多
Application of organic waste to saline alkaline soils is considered to be a good practice for soil remediation. The effects of applying different organic amendments （e.g., cattle dung, vermicompost, biofertilizer） a...Application of organic waste to saline alkaline soils is considered to be a good practice for soil remediation. The effects of applying different organic amendments （e.g., cattle dung, vermicompost, biofertilizer） and earthworm inoculations （Eisenia fetida） on saline soils and cotton growth were investigated during i year of cotton cultivation. Compared to the control （applied with inorganic NPK fertilizer）, applying organic amendments improved soil physicochemical properties. Biofertilizer application improved available nutrient content, reduced short-term soil electrical conductivity, and produced the highest cotton yield, whereas cattle dung and vermicompost applications resulted in higher soil organic matter content. Application of organic amendments significantly increased soil microbial biomass carbon during the flowering period, which sharply declined at harvest. This was especially true for the biofertilizer treatment, which also exhibited lower nematode abundance compared with the other organic materials. Earthworm inoculation following cattle dung application failed to significantly change soil physicochemical properties when compared to the treatments without earthworm inoculation. Results suggest that biofertilizer application to saline soil would improve soil nutrient status in the short-term, whereas cattle dung application would improve soil organic matter content and increase soil organism abundance to a greater extent. However, different strategies might be required for long-term saline soil remediation.展开更多
Background:Bacillus amyloliquefaciens(BA)and Bacillus subtilis(BS)are usually used as feed supplements directly or bacterial inoculants in biological feeds for animals.However,few research have reported the effects of...Background:Bacillus amyloliquefaciens(BA)and Bacillus subtilis(BS)are usually used as feed supplements directly or bacterial inoculants in biological feeds for animals.However,few research have reported the effects of BA and BS on fermentation characteristics and bacterial community successions of whole-plant corn silage during ensiling.If the BA and BS inoculants have positive effects on silages,then they could not only improve fermentation characteristics,but also deliver BA or BS viable cells to ruminants,which would play its probiotic effect.Therefore,the objectives of this study were to investigate the effects of BA and BS on the fermentation,chemical characteristics,bacterial community and their metabolic pathway of whole-plant corn silage.Results:Freshly chopped whole-plant corn was inoculated without or with BA and BS,respectively,and ensiled for1,3,7,14 and 60 d.Results showed that BA and BS inoculations increased lactic acid concentrations of whole-plant corn silages compared with control,and BA inoculation decreased acetic acid concentrations,whereas BS inoculation decreased fiber contents and increased crude protein(CP)content.Higher water-soluble carbohydrate contents and lower starch contents were observed in BA-and BS-inoculated silages compared with that in control.The decreased CP content and increased non-protein nitrogen content were observed in BA-inoculated silage,which was consistent with the higher amino acid metabolism abundances observed in BA-inoculated silage.In addition,it was noteworthy that BA and BS inoculations increased the metabolism of cofactors and vitamins,and decreased the relative abundances of drug resistance:antimicrobial pathways.We also found that the bacterial metabolism pathways were clearly separated into three clusters based on the ensiling times of whole-plant corn silage in the present study.There were no significant differences in bacterial community compositions among the three groups during ensiling.However,BA and BS inoculations decreased the relative abundances of undesirable bacteria such as Acetobacter and Acinetobacter.Conclusion:Our findings suggested that the BS strain was more suitable as silage inoculants than the BA strain in whole-plant corn silage in this study.展开更多
Agricultural areas of land are deteriorating every day owing to population increase, rapid urbanization, and industrialization. To feed today’s huge populations, increased crop production is required from smaller are...Agricultural areas of land are deteriorating every day owing to population increase, rapid urbanization, and industrialization. To feed today’s huge populations, increased crop production is required from smaller areas, which warrants the continuous application of high doses of inorganic fertilizers to agricultural land. These cause damage to soil health and, therefore, nutrient imbalance conditions in arable soils. Under these conditions, the benefits of microbial inoculants (such as Actinobacteria) as replacements for harmful chemicals and promoting ecofriendly sustainable farming practices have been made clear through recent technological advances. There are multifunctional traits involved in the production of different types of bioactive compounds responsible for plant growth promotion, and the biocontrol of phytopathogens has reduced the use of chemical fertilizers and pesticides. There are some well-known groups of nitrogen-fixing Actinobacteria, such as Frankia, which undergo mutualism with plants and offer enhanced symbiotic trade-offs.In addition to nitrogen fixation, increasing availability of major plant nutrients in soil due to the solubilization of immobilized forms of phosphorus and potassium compounds, production of phytohormones, such as indole-3-acetic acid, indole-3-pyruvic acid, gibberellins, and cytokinins, improving organic matter decomposition by releasing cellulases, xylanase, glucanases, lipases, and proteases, and suppression of soil-borne pathogens by the production of siderophores, ammonia, hydrogen cyanide, and chitinase are important features of Actinobacteria useful for combating biotic and abiotic stresses in plants.The positive influence of Actinobacteria on soil fertility and plant health has motivated us to compile this review of important findings associated with sustaining plant productivity in the long run.展开更多
Fungi are often used to induce agarwood inAquilariatrees. This study was conducted to evaluate the effect of several fungi on agarwood formation over time in youngAquilaria malaccensis （Lam.） trees. Typical changes ...Fungi are often used to induce agarwood inAquilariatrees. This study was conducted to evaluate the effect of several fungi on agarwood formation over time in youngAquilaria malaccensis （Lam.） trees. Typical changes in the length and light intensity of the resulting discoloration were observed after three and six month periods following inoculation. Wood samples were observed microscopically and classified into several light intensity groups. The discoloration length was meas-ured longitudinally. The duration after inoculation affected the mean of discoloration length： the 6-month old sample （1.70 cm） had a wider discoloration zone when compared to the 3-month old sample （1.17 cm）. When measuring the discoloration intensity, a positive relationship with time was perceived. Digital images, captured using a camera-equipped microscope, revealed that wood samples collected after six months appeared to be 1.8-times darker than after three months. We concluded that time, not the species of any of the tested fungi, had significant effect on discoloration length and intensity. Gas chromatography/mass spec-trometry （GCMS） analysis of the 6-month old sample yielded some important agarwood compounds such as benzylacetone, anisylacetone, guaiene and palustrol. This demonstrates that the tested fungi have the ability to induce agarwood formation in nurseryA. malaccensis trees.展开更多
The incorporation of straw with a microbial inoculant(a mixture of bacteria and fungi, designed to accelerate straw decomposition)is being increasingly adopted within the agricultural sector in China. However, its eff...The incorporation of straw with a microbial inoculant(a mixture of bacteria and fungi, designed to accelerate straw decomposition)is being increasingly adopted within the agricultural sector in China. However, its effects on N and C trace gas emissions remain unclear.We conducted a field experiment to investigate the effects of different straw incorporation methods(with and without microbial inoculant) in the wheat season on nitrous oxide(N_2O) and methane(CH_4) emissions from a wheat-rice rotation system in China.The treatments comprised N, P, and K fertilizers only(NPK), NPK plus rice straw(NPKS), NPKS plus Ruilaite microbial inoculant(NPKSR), and NPKS plus Jinkuizi microbial inoculant(NPKSJ). Rice straw incorporation before wheat sowing significantly decreased N_2O emissions during the wheat season and stimulated N_2O and CH_4 emissions during the subsequent rice season. Compared with the NPKS treatment, the NPKSR and NPKSJ treatments decreased N_2O emissions during the wheat season, but had no effect on N_2O or CH_4 emissions during the subsequent rice season. Annually, the two treatments were comparable regarding N_2O emissions.Although the global warming potentials of the NPKSR and NPKSJ treatments were lower than that of the NPKS treatment during the wheat season, no significant differences were observed during the subsequent rice season, or over the entire rotation cycle. The annual greenhouse gas intensity was slightly lower in the NPKSR and NPKSJ treatments than in the NPKS treatment. Overall, these results suggest that the incorporation of rice straw with a microbial inoculant in the wheat season was the best strategy tested for managing straw resources within the wheat-rice rotation system.展开更多
As a potent nucleating substrate forα-Mg grain,MgAl_(2)O_(4) powder was used to inoculate the Mg-Al melt in this study.The effects of MgAl_(2)O_(4)amount,holding time and Al content on the grain size and grain refini...As a potent nucleating substrate forα-Mg grain,MgAl_(2)O_(4) powder was used to inoculate the Mg-Al melt in this study.The effects of MgAl_(2)O_(4)amount,holding time and Al content on the grain size and grain refining ratio of the inoculated Mg-Al alloys are systematically investigated.The results show that the minimum grain size of Mg-3Al alloy is achieved by adding 2wt.%MgAl_(2)O_(4)powder and this alloy exhibits higher grain refining ratio than Mg-5Al and Mg-8Al alloys.The crystallographic misfit calculation indicates the wellmatching and possible orientation relationships(ORs)betweenα-Mg and MgAl_(2)O_(4).Among these predicted ORs,[10–10]α−Mg//[110]MgAl2O4 in(0002)α−Mg//(1–13)MgAl2O4 possesses the smallest misfit,i.e.,2.34%(fr).Both results of the experiment and crystallographic calculation demonstrate that the grain refinement of Mg-Al alloys is attributed to the MgAl_(2)O_(4)particles acting as the heterogeneous nucleation substrates forα-Mg grains.展开更多
The effect of inoculation with arbuscular mycorrhizal(AM) fungi( Acaulospora lavis ) on the degradation of di(2 ethylhexyl) phthalate(DEHP) in soil was studies. Cowpea plants (Pigna sinensis) were used as host p...The effect of inoculation with arbuscular mycorrhizal(AM) fungi( Acaulospora lavis ) on the degradation of di(2 ethylhexyl) phthalate(DEHP) in soil was studies. Cowpea plants (Pigna sinensis) were used as host plants and grown in a specially designed rhizobox. The experimental results indicated that, both in sterile and non sterile soil, mycorrhizal colonization rates were much higher in the mycorrhizal plants than in the non mycorrhizal plants. Addition of 4 mg/kg DEHP slightly affected mycorrhizal colonization, but the addition of 100 mg/kg DEHP significantly decreased mycorrhizal colonization. DEHP degradation in the mycorrhizosphere(Ms) and hyphosphere(Hs), especially in the Hs, increased after inoculation with Acaulospora lavis . It is concluded that mycorrhizal hyphae play an important role in the plant uptake, degradation and translocation of DEHP. The mechanism might be attributed to increased numbers of bacteria and actinomycetes and activity of dehydrogenase, urease and acid phosphatase in the Ms and Hs by mycorrhizal fungi.展开更多
基金supported by the Jiangsu Science and Technology Plan Project(No.BE2022420)the Innovation and Promotion of Forestry Science and Technology Program of Jiangsu Province(No.LYKJ[2021]30)+2 种基金the Scientific Research Project of Baishanzu National Park(No.2021ZDLY01)the Ningxia key research and development plan(No.2021BEG02010)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Mining activities have caused significant land degradation globally,emphasizing the need for effective restoration.Microbial inoculants offer a promising solution for sustainable remediation by enhancing soil nutrients,enzyme activities,and microbial communities to support plant growth.However,the mechanisms by which inoculants influence soil microbes and their relationship with plant growth require further investigation.Metagenomic sequencing was employed for this study,based on a one-year greenhouse experiment,to elucidate the effects of Bacillus thuringiensis NL-11 on the microbial functions of abandoned mine soils.Our findings revealed that the application of microbial inoculants significantly enhanced the soil total carbon(TC),total sulfur(TS),organic carbon(SOC),available phosphorus(AP),ammonium(NH4+),urease,arylsulfatase,phosphatase,β-1,4-glucosidase(BG),β-1,4-N-acetylglucosaminidase(NAG).Moreover,this led to substantial improvements in plant height,as well as aboveground and belowground biomass.Microbial inoculants impacted functional gene structures without altering diversity.The normalized abundance of genes related to the degradation of carbon and nitrogen,methane metabolism,and nitrogen fixation were observed to increase,as well as the functional genes related to phosphorus cycling.Significant correlations were found between nutrient cycling gene abundance and plant biomass.Partial Least Squares Path Model analysis showed that microbial inoculants not only directly influenced plant biomass but also indirectly affected the plant biomass through C cycle modifications.This study highlights the role of microbial inoculants in promoting plant growth and soil restoration by improving soil properties and enhancing normalized abundance of nutrient cycling gene,making them essential for the recovery of abandoned mine sites.
基金supported by the Agricultural Science and Technology Innovation Program(CAAS-ZDRW202416)the Foundation of Hubei Hongshan Laboratory(2021hszd015)+1 种基金the Science and Technology Major Projects of Hubei Province(2023BBA002)the Knowledge Innovation Program of Wuhan-Basi Research(2023020201010126)。
文摘Peanuts are important oilseed legume crops that are susceptible to contamination by Aspergillus flavus in soil,leading to serious economic losses.Previously,our research team developed the Aspergillus-Rihizobia coupling(ARC)microbial inoculants and found it can reduce A.flavus abundance in the soil and promote efficient nodulation in peanuts.However,the impact of ARC microbial inoculants on different resistant varieties of A.flavus remains unclear.In this study,we screened peanut varieties that were resistant and susceptible to A.flavus and evaluated their nodulation ability and growth performance after ARC microbial inoculants treatment in the field.The results demonstrated that the nodule number and nitrogenase activity of both varieties significantly increased after ARC microbial inoculants treatment,with the highly susceptible variety AH24 showing a greater increase.For photosynthetic parameters,both varieties also increased after ARC microbial inoculants treatment,but the increase was greater in the moderately resistant variety AH1 than in the highly susceptible variety AH24.Finally,we found that the yield and yield-related traits of the moderately resistant variety AH1 were better than those of the highly susceptible variety AH24.After ARC microbial inoculants treatment,the yield traits of both peanut varieties still increased significantly,but the degree of increase of the moderately resistant variety AH1 was smaller than that of the highly susceptible variety AH24.In addition,the abundance of A.flavus in the rhizosphere soil of the two varieties significantly decreased after ARC microbial inoculants treatment,with no significant difference between the varieties.These results indicated that ARC microbial inoculants exert differential effects on the nodulation and growth of different resistant peanut varieties and have a better effect on highly susceptible varieties.These results provide a solid theoretical basis for the efficient use of ARC microbial inoculants in the field of peanuts in the future.
文摘Synthetic fertilizers are widely used to address the urgent challenge of ensuring food supplies for a growing world population in the context of climate change. However, their industrial production and use in agriculture have a negative impact on the environment and consequently on human health. While chemical fertilizers may not have to be abandoned in agricultural production systems, limiting their use could help to make agriculture sustainable and resilient to climate change. In Senegal, the level of mineral fertilizers used in market gardening has become alarming in the Niayes area. As a result, microbial biotechnologies have been promoted for biofertilizer production of common bean (Phaseolus vulgaris L.) cultivation. Rhizobial inoculums have thus been used to reduce the rate of chemical nitrogen fertilizers being applied in cropping systems. Several investigations in the laboratory, on experimental stations and in the field have shown a possibility of a significant reduction in the use of nitrogen fertilizers in common bean production. Conventional mineral fertilization use can be reduced from over 120 kg N/ha to 20 kg N/ha. This contributes both to a very significant reduction in the application rate with the same level of yield and to an improvement in the standard of living. In addition, the environmental impact of using chemical fertilizers can be mitigated. This study is a contribution to the promotion of biofertilizers adoption in agricultural systems.
基金supported by the Key Science and Technology Project of Anhui Province,China(2023n06020056)the National Natural Science Foundation of China(32071628)the Colleges and Universities Science Foundation of Anhui Province,China(2024AH020002)。
文摘Although the application of straw decomposing microorganism inoculants(SDMI)can accelerate straw decomposition,the underlying mechanisms affecting soil organic carbon(SOC)under different scenarios remain unclear.We conducted a meta-analysis using 226 observations from 86 studies on SOC changes under straw return with or without SDMI applications.Overall,our results indicated that straw with SDMI application increased the SOC stock by 1.51%at an initial carbon-to-nitrogen ratio(ICNR)>25(P<0.05),while the effect of ICNR≤25was insignificant.In particular,at ICNR>25,application of SDMI-treated straw increased SOC stocks in northern temperate continental areas(NTC)higher than in subtropical monsoon regions(STM).Furthermore,the straw with SDMI application increased higher SOC stocks in soils with pH>7.5 than those with pH≤7.5.In terms of agricultural management practices,SOC stocks were significantly higher in straw buried(SB),the experimental duration of straw return(EDSR)≥1 year,the straw return amount(SRA)>6,000 kg ha^(–1),and the SDMI application rate(SDMIR)>30 kg ha^(–1)conditions.The effect of straw with SDMI on SOC stocks under straw burying(SB)was significantly higher than that under straw mulching(SM)at ICNR≤25.At ICNR>25,EDSR,SDMIR,and the mean annual precipitation(MAP)were the main drivers of the effect of SDMI addition to straw on SOC stocks.Straw with SDMI induced SOC stock increases which increased with EDSR and decreased with increasing MAP.These findings provide a scientific basis for decision-makers and stakeholders to improve soil C management via the application of SDMI-amended straw at both regional and large scales.
基金support of Taishan Scholar Foundation of Shandong Province(tsqn201909073,tsqn201812034)National Natural Science Foundation of China(31872951)。
文摘The Agrobacterium-mediated transient expression system with conventional binary vectors is well established in tobacco leaves,while the same system applied to tomato leaflets has relatively low expression efficiency.However,impacts of the leaf age,inoculation method and incubation condition after Agrobacterium infiltration on transient protein expression efficiency are seldom investigated.In this study,we optimize Agrobacterium-mediated transient expression system using conventional binary vectors to achieve the high efficiency of target gene expression in tomato leaflets.We transiently express GFP and a nucleus-localized gene SlUVI4 fused with GFP in detached 10-,20-,and 30-day-old leaflets.The cutting points of leaflets are embedded in MS medium after the Agrobacterium-mediated vacuum infiltration,and all leaflets are kept in the dark before use.The 10-and 30-day-old leaflets have more damage than 20-day-old leaflets after the infiltration.
基金supported by the China Agriculture Research System of Ministry of Finance of the People’s Republic of China(MOF)Ministry of Agriculture+1 种基金Rural Affairs of the People’s Republic of China(MARA)(CARS-38)S&T Program of Hebei(215A7101D).
文摘Microbial growth causes lamb spoilage.This study explored the spoilage ability of Latilactobacillus sakei,Serratia proteamaculans and Hafnia proteus in vacuum-packed raw lamb,including growth ability,degradation of protein and lipid,and change of volatile organic compounds(VOCs)profile,meanwhile screened the key VOCs produced by the targeted strains with meat background excluding,finally confirmed the volatile spoilage marker of vacuum-packaged lamb by comparing with our previous work.The results showed that L.sakei,S.proteamaculans and H.proteus had excellent growth ability.L.sakei inoculated group significantly reduced the pH value,showed higher trichloroacetic acid-soluble peptides content,and excellently degraded sarcoplasmic and myofibrillar proteins.About free amino acids,L.sakei significantly degraded serine,arginine and aspartic acid,while S.proteamaculans and H.proteus significantly degraded serine and lysine.In addition,L.sakei had the strongest effect on promoting free fatty acid production,followed by S.proteamaculans and finally H.proteus.Evaluating from various indicators,the co-culture of the three strains did not have any effect.The key volatiles produced by L.sakei were 1-hexanol,acetic acid and hexanoic acid,S.proteamaculans produced 1-hexanol and acetoin,and H.proteus produced 1-hexanol,acetic acid and acetoin.In the end,1-hexanol,hexanoic acid and acetoin were proven to be spoilage markers for vacuum-packaged and chilled lamb.This study can provide fundamental information for inhibiting and rapid identification of spoilage in vacuum-packaged lamb.
基金supported by the National Natural Science Foundation of China(Nos.52374396 and 52122409).
文摘Improving the high-temperature performance of Inconel 718(IN718)alloys manufactured via laser powder bed fusion(LPBF)has been the most concerned issue in the industry.In this study,the effects of Ti_(2)AlC inoculants on microstructures and high-temperature mechanical properties of the as-built IN718 composites were investigated.According to statistical results of relative density and unmelted particle area in as-built alloys,the optimal energy of 112 J/mm^(3)was determined.It was observed that the precipitation of the MC carbide was significantly enhanced with the addition of Ti_(2)AlC,restricting the precipitation of the Laves phase.The MC particles were uniformly distributed along the subgrain boundaries,which contributed to the dispersion strengthening.Meanwhile,the MC particles served as nucleation sites for heterogeneous nucleation during the solidification process,facilitating the refinement of columnar and cellular grains.The simulated Scheil-Gulliver curves showed that the precipitation sequence of phases did not change with Ti_(2)AlC inoculants.The as-built 1%Ti_(2)AlC/IN718 sample demonstrated an ultimate tensile strength of 998.78 MPa and an elongation of 18.04%at 650℃,revealing a markedly improved mechanical performance compared with the LPBF-manufactured IN718 alloys.The high-temperature tensile strength of 1%Ti_(2)AlC/IN718 sample increased to 1197.99 MPa by heat treatment.It was suggested that dislocation strengthening and ordered strengthening were two most important reinforcement mechanisms.
基金Projects(51074031,51271042,50874022)supported by the National Natural Science Foundation of ChinaProject(2013M530913)supported by the China Postdoctoral Science FoundationProject(DUT12RC(3)35)supported by the Fundamental Research Funds for the Central Universities of China
文摘The combined effects of direct current pulsed magnetic field （DC-PMF） and inoculation on pure aluminum were investigated, the grain refinement behavior of DC-PMF and inoculation was discussed. The experimental results indicate that the solidification micro structure of pure aluminum can be greatly refined under DC-PMF. Refinement of pure aluminum is attributed to electromagnetic undercooling and forced convection caused by DC-PMF. With single DC-PMF, the grain size in the equiaxed zone is uneven. However, under DC-PMF, by adding 0.05% （mass fraction） Al5Ti-B, the grain size of the sample is smaller, and the size distribution is more uniform than that of single DC-PMF. Furthermore, under the combination of DC-PMF and inoculation, with the increase of output current, the grain size is further reduced. When the output current increases to 100 A, the average grain size can decrease to 113 μn.
基金Supported by the Scientific Research Project of Neijiang Normal Unverisity(No:07NJZ-03)~~
文摘[Objective] This study aimed to explore the inoculation effects of Dendrobium officinale mycorrhizal fungi on their plantlets. [Method] Endophytic strains Tj1, Tj2 and Tj3 were obtained by isolation and purification from mycorrhiza of wild Dendrobium officinale and inoculated on the root system of Dendrobium officinale for inoculation test. [Result] Under tissue-culture conditions, at early stage, Tj1 strain hadn＇t shown promotion effect on Dendrobium officinale, Tj2 strain had shown relatively strong promotion effects, and Tj3 strain had promoted the growth of roots; at late stage, Tj1 strain had shown relatively strong promotion effects, Tj2 strain had shown the best inoculation effects and the strongest promotion effects, while Tj3 strain had caused root and seedling rot problems of the plantlets; under outdoor conditions, after inoculation with Tj2 strain, the number of leaves and lateral buds were increased, the growth of lateral root and the increase of plant height were significant, the leaves of Dendrobium officinale plantlets were large and dark green and an obvious root enlargement phenomenon was observed. [Conclusion] The two inoculation methods both indicate that Tj2 strain has relatively strong promotion effects on the growth of Dendrobium officinale roots and shoots, the increase of plant number and plant height, and the germination of new shoots and roots, which proved the effective establishment of symbiotic relationship between Tj2 strain and Dendrobium officinale. Therefore, T2 strain has practical application values on the successful cultivation of Dendrobium officinale plantlets.
基金Supported by National Natural Science Foundation of China(30870109)~~
文摘[Objective]The aim of this study was to identify transient expression of movement protein （MP） gene in Nicotinana benthaminana rapidly and further investigate the function of this exogenous gene. [Method]The movement protein gene of barley yellow dwarf virus （BYDV） was cloned into potato virus X （PVX） viral vector of pGR107,and PVX-recombinant vector was obtained. After electroporation of Agrobacterium tumefaciens,PVX was inoculated into the lower leaves of tobacco by Agrobacterium infiltration assay to observe the infection of virus on tobacco. [Result]After infection for 7 days,upper non-inoculated leaves of tobacco infected by the PVX-recombinant vector showed the virus infection symptoms,while the control group had no viral infection phenomenon. Daily follow-up observations for two groups revealed that tobacco infected by PVX-recombinant vector had severe symptoms of virus infection and curling leaves,or even led to necrosis both in infiltrated and systemic leaves in late period. However,tobacco infected by PVX vector had only slight symptoms of virus infection and could recover from infection. RT-PCR of the infected tobacco indicated that exogenous gene BYDV-MP had a normal transcription and expression in tobacco. [Conclusion]As a determinant factor for viral disease,BYDV-MP promotes the systemic infection rate of PVX and its symptom. In addition,it is feasible to express exogenous MP gene in Nicotiana benthaminan via PVX expression vector.
基金Project (50901034) supported by the National Natural Science Foundation of China (NSFC)Project (2010-1174) supported by Scientific Research Foundation (SRF) for the Returned Overseas Chinese Scholars (ROCS), State Education Ministry (SEM)Project (2012ZZ0005)supported by the Fundamental Research Funds for the Central Universities, South China University of Technology, China
文摘Mg-3%Al alloy was modified by combining Ca addition with carbon inoculation. The effects of Fe addition and addition sequence on the grain refinement were investigated. A higher grain refining efficiency could be obtained for the Mg-Al alloy modified by combining Ca addition with carbon inoculation. Fe addition and addition sequence had no obvious effect on the grain refinement. Ca addition could effectively avoid grain-coarsening resulting from Fe in the carbon-inoculated Mg-Al alloy. The Al-C-O particles, actually being Al4C3, should act as potent substrates for a-Mg grains in the sample treated by combining Ca addition with carbon inoculation. However, the duplex-phase particles of AI4C3 coated on Al-Fe or Al-C-Fe should be the potent substrates for a-Mg grains if Fe existed in the Mg-Al melt. Ca addition can contribute to the formation of the particles of Al4C3 coated on Al-Fe or Al-C-Fe, regardless of the Fe addition sequence. The poisoning effect of Fe was effectively inhibited in the carbon-inoculated of Mg-Al alloy due to Ca addition, namely, Ca has a poisoning-free effect.
文摘To fit the special needs of gray cast iron as a new engineering material,i.e.,higher σ b and lower HB,or lower σ b and higher HB,using the method of heat analyzing and polyparameters analytic figures,the synthetic rules of carbon saturation degree,inoculation degree and mechanical properties can be exposed.The result shows that,according to the needs of the part′s mechanical properties,referring to the synthetic rules of gray cast iron,the corresponding technological measure and composition proportion can be defined,by which we will get the exact mechanical properties that could achieve the result expected completely.Thus,the casting for gray cast iron might be 'designed'from'selected'.
基金supported by the National Natural Science Foundation of China (No. 41371305)the National Key Research and Development Program of China (No. 2017YFD0202000)
文摘Application of organic waste to saline alkaline soils is considered to be a good practice for soil remediation. The effects of applying different organic amendments （e.g., cattle dung, vermicompost, biofertilizer） and earthworm inoculations （Eisenia fetida） on saline soils and cotton growth were investigated during i year of cotton cultivation. Compared to the control （applied with inorganic NPK fertilizer）, applying organic amendments improved soil physicochemical properties. Biofertilizer application improved available nutrient content, reduced short-term soil electrical conductivity, and produced the highest cotton yield, whereas cattle dung and vermicompost applications resulted in higher soil organic matter content. Application of organic amendments significantly increased soil microbial biomass carbon during the flowering period, which sharply declined at harvest. This was especially true for the biofertilizer treatment, which also exhibited lower nematode abundance compared with the other organic materials. Earthworm inoculation following cattle dung application failed to significantly change soil physicochemical properties when compared to the treatments without earthworm inoculation. Results suggest that biofertilizer application to saline soil would improve soil nutrient status in the short-term, whereas cattle dung application would improve soil organic matter content and increase soil organism abundance to a greater extent. However, different strategies might be required for long-term saline soil remediation.
基金funded by National Natural Science Foundation of China(project no.31872417)。
文摘Background:Bacillus amyloliquefaciens(BA)and Bacillus subtilis(BS)are usually used as feed supplements directly or bacterial inoculants in biological feeds for animals.However,few research have reported the effects of BA and BS on fermentation characteristics and bacterial community successions of whole-plant corn silage during ensiling.If the BA and BS inoculants have positive effects on silages,then they could not only improve fermentation characteristics,but also deliver BA or BS viable cells to ruminants,which would play its probiotic effect.Therefore,the objectives of this study were to investigate the effects of BA and BS on the fermentation,chemical characteristics,bacterial community and their metabolic pathway of whole-plant corn silage.Results:Freshly chopped whole-plant corn was inoculated without or with BA and BS,respectively,and ensiled for1,3,7,14 and 60 d.Results showed that BA and BS inoculations increased lactic acid concentrations of whole-plant corn silages compared with control,and BA inoculation decreased acetic acid concentrations,whereas BS inoculation decreased fiber contents and increased crude protein(CP)content.Higher water-soluble carbohydrate contents and lower starch contents were observed in BA-and BS-inoculated silages compared with that in control.The decreased CP content and increased non-protein nitrogen content were observed in BA-inoculated silage,which was consistent with the higher amino acid metabolism abundances observed in BA-inoculated silage.In addition,it was noteworthy that BA and BS inoculations increased the metabolism of cofactors and vitamins,and decreased the relative abundances of drug resistance:antimicrobial pathways.We also found that the bacterial metabolism pathways were clearly separated into three clusters based on the ensiling times of whole-plant corn silage in the present study.There were no significant differences in bacterial community compositions among the three groups during ensiling.However,BA and BS inoculations decreased the relative abundances of undesirable bacteria such as Acetobacter and Acinetobacter.Conclusion:Our findings suggested that the BS strain was more suitable as silage inoculants than the BA strain in whole-plant corn silage in this study.
文摘Agricultural areas of land are deteriorating every day owing to population increase, rapid urbanization, and industrialization. To feed today’s huge populations, increased crop production is required from smaller areas, which warrants the continuous application of high doses of inorganic fertilizers to agricultural land. These cause damage to soil health and, therefore, nutrient imbalance conditions in arable soils. Under these conditions, the benefits of microbial inoculants (such as Actinobacteria) as replacements for harmful chemicals and promoting ecofriendly sustainable farming practices have been made clear through recent technological advances. There are multifunctional traits involved in the production of different types of bioactive compounds responsible for plant growth promotion, and the biocontrol of phytopathogens has reduced the use of chemical fertilizers and pesticides. There are some well-known groups of nitrogen-fixing Actinobacteria, such as Frankia, which undergo mutualism with plants and offer enhanced symbiotic trade-offs.In addition to nitrogen fixation, increasing availability of major plant nutrients in soil due to the solubilization of immobilized forms of phosphorus and potassium compounds, production of phytohormones, such as indole-3-acetic acid, indole-3-pyruvic acid, gibberellins, and cytokinins, improving organic matter decomposition by releasing cellulases, xylanase, glucanases, lipases, and proteases, and suppression of soil-borne pathogens by the production of siderophores, ammonia, hydrogen cyanide, and chitinase are important features of Actinobacteria useful for combating biotic and abiotic stresses in plants.The positive influence of Actinobacteria on soil fertility and plant health has motivated us to compile this review of important findings associated with sustaining plant productivity in the long run.
基金supported by the Universiti Putra Malaysia Research University Grant Scheme(Project No.03-03-11-1438RU)
文摘Fungi are often used to induce agarwood inAquilariatrees. This study was conducted to evaluate the effect of several fungi on agarwood formation over time in youngAquilaria malaccensis （Lam.） trees. Typical changes in the length and light intensity of the resulting discoloration were observed after three and six month periods following inoculation. Wood samples were observed microscopically and classified into several light intensity groups. The discoloration length was meas-ured longitudinally. The duration after inoculation affected the mean of discoloration length： the 6-month old sample （1.70 cm） had a wider discoloration zone when compared to the 3-month old sample （1.17 cm）. When measuring the discoloration intensity, a positive relationship with time was perceived. Digital images, captured using a camera-equipped microscope, revealed that wood samples collected after six months appeared to be 1.8-times darker than after three months. We concluded that time, not the species of any of the tested fungi, had significant effect on discoloration length and intensity. Gas chromatography/mass spec-trometry （GCMS） analysis of the 6-month old sample yielded some important agarwood compounds such as benzylacetone, anisylacetone, guaiene and palustrol. This demonstrates that the tested fungi have the ability to induce agarwood formation in nurseryA. malaccensis trees.
基金supported by the "Strategic Priority Research Program" of Chinese Academy of Sciences (No. XDB15020103)the National Natural Sciences Foundation of China (Nos. 41671241 and 41571232)the Knowledge Innovation Program of Institute of Soil Science, Chinese Academy of Sciences (Nos. ISSASIP1652 and ISSASIP1654)
文摘The incorporation of straw with a microbial inoculant(a mixture of bacteria and fungi, designed to accelerate straw decomposition)is being increasingly adopted within the agricultural sector in China. However, its effects on N and C trace gas emissions remain unclear.We conducted a field experiment to investigate the effects of different straw incorporation methods(with and without microbial inoculant) in the wheat season on nitrous oxide(N_2O) and methane(CH_4) emissions from a wheat-rice rotation system in China.The treatments comprised N, P, and K fertilizers only(NPK), NPK plus rice straw(NPKS), NPKS plus Ruilaite microbial inoculant(NPKSR), and NPKS plus Jinkuizi microbial inoculant(NPKSJ). Rice straw incorporation before wheat sowing significantly decreased N_2O emissions during the wheat season and stimulated N_2O and CH_4 emissions during the subsequent rice season. Compared with the NPKS treatment, the NPKSR and NPKSJ treatments decreased N_2O emissions during the wheat season, but had no effect on N_2O or CH_4 emissions during the subsequent rice season. Annually, the two treatments were comparable regarding N_2O emissions.Although the global warming potentials of the NPKSR and NPKSJ treatments were lower than that of the NPKS treatment during the wheat season, no significant differences were observed during the subsequent rice season, or over the entire rotation cycle. The annual greenhouse gas intensity was slightly lower in the NPKSR and NPKSJ treatments than in the NPKS treatment. Overall, these results suggest that the incorporation of rice straw with a microbial inoculant in the wheat season was the best strategy tested for managing straw resources within the wheat-rice rotation system.
基金This work was supported by the National Natural Science Foundation of China(51871100).
文摘As a potent nucleating substrate forα-Mg grain,MgAl_(2)O_(4) powder was used to inoculate the Mg-Al melt in this study.The effects of MgAl_(2)O_(4)amount,holding time and Al content on the grain size and grain refining ratio of the inoculated Mg-Al alloys are systematically investigated.The results show that the minimum grain size of Mg-3Al alloy is achieved by adding 2wt.%MgAl_(2)O_(4)powder and this alloy exhibits higher grain refining ratio than Mg-5Al and Mg-8Al alloys.The crystallographic misfit calculation indicates the wellmatching and possible orientation relationships(ORs)betweenα-Mg and MgAl_(2)O_(4).Among these predicted ORs,[10–10]α−Mg//[110]MgAl2O4 in(0002)α−Mg//(1–13)MgAl2O4 possesses the smallest misfit,i.e.,2.34%(fr).Both results of the experiment and crystallographic calculation demonstrate that the grain refinement of Mg-Al alloys is attributed to the MgAl_(2)O_(4)particles acting as the heterogeneous nucleation substrates forα-Mg grains.
基金TheNationalKeyBasicScienceResearchProjectofChina (No .G1 9990 1 1 80 6)
文摘The effect of inoculation with arbuscular mycorrhizal(AM) fungi( Acaulospora lavis ) on the degradation of di(2 ethylhexyl) phthalate(DEHP) in soil was studies. Cowpea plants (Pigna sinensis) were used as host plants and grown in a specially designed rhizobox. The experimental results indicated that, both in sterile and non sterile soil, mycorrhizal colonization rates were much higher in the mycorrhizal plants than in the non mycorrhizal plants. Addition of 4 mg/kg DEHP slightly affected mycorrhizal colonization, but the addition of 100 mg/kg DEHP significantly decreased mycorrhizal colonization. DEHP degradation in the mycorrhizosphere(Ms) and hyphosphere(Hs), especially in the Hs, increased after inoculation with Acaulospora lavis . It is concluded that mycorrhizal hyphae play an important role in the plant uptake, degradation and translocation of DEHP. The mechanism might be attributed to increased numbers of bacteria and actinomycetes and activity of dehydrogenase, urease and acid phosphatase in the Ms and Hs by mycorrhizal fungi.
