Fine mapping and characterization of a major QTL for grain length,QGl.cau-2D.1,that has pleiotropic effects in synthetic allohexaploid wheat

Grain size is one of the determinants of grain yield,and identifying the genetic loci that control grain size will be helpful for increasing grain yield.In our previous study,a quantitative trait locus(QTL)for grain length(GL),QGl.cau-2D.1,was identified from an F2 population developed from the cross between the natural(TAA10)and synthetic(XX329)allohexaploid wheat.In the present study,we mainly fine mapped and validated its genetic effects.To this end,multiple near-isogenic lines(NILs)were obtained through marker-assisted selection with TAA10 as the recurrent parent.The secondary populations derived from 25 heterozygous recombinants were used for fine mapping of QGl.cau-2D.1,and the allele from XX329 significantly increased GL,thousand-grain weight(TGW),total spikelet number per spike(TSN)and spike compactness(SC).Using NILs for XX329(2D+)and TAA10(2D−),we determined the genetic and pleiotropic effects of QGl.cau-2D.1.The target sequences were aligned with the wheat reference genome RefSeq v2.1 and spanned an~0.9 Mb genomic region.TraesCS2D03G0114900(ortholog of Os03g0594700)was predicted as the candidate gene based on whole-genome re-sequencing and expression analyses.In summary,the map-based cloning of QGl.cau-2D.1 will be useful for improving grain weight with enhanced GL and TSN.

Legume green manure can intensify the function of chemical nitrogen fertilizer substitution via increasing nitrogen supply and uptake of wheat

Achieving the green development of agriculture requires the reduction of chemical nitrogen(N)fertilizer input.Previous studies have confirmed that returning green manure to the field is an effective measure to improve crop yields while substituting partial chemical N fertilizer.However,it remains unclear how to further intensify the substituting function of green manure and elucidate its underlying agronomic mechanism.In a split-plot field experiment in spring wheat,different green manures returned to the field under reduced chemical N supply was established in an oasis area since 2018,in order to investigate the effect of green manure and reduced N on grain yield,N uptake,N use efficiency(NUE),N nutrition index,soil organic matter,and soil N of wheat in 2020-2022.Our results showed that mixed sown common vetch and hairy vetch can substitute 40%of chemical N fertilizer without reducing grain yield or N accumulation.Noteworthily,mixed sown common vetch and hairy vetch under reduced N by 20%showed the highest N agronomy efficiency and recovery efficiency,which were 92.0%and 46.0%higher than fallow after wheat harvest and conventional N application rate,respectively.The increase in NUE of wheat was mainly attributed to mixed sown common vetch and hairy vetch,which increased N transportation quantity and transportation rate at pre-anthesis,enhanced N harvest index,optimized N nutrition index,and increased activities of nitrate reductase and glutamine synthetase of leaf,respectively.Meanwhile,mixed sown common vetch and hairy vetch under reduced N by 20%improved soil organic matter and N contents.Therefore,mixed sown common vetch and hairy vetch can substitute 40%of chemical N fertilizer while maintaining grain yield and N accumulation,and it combined with reduced chemical N by 20%or 40%improved NUE of wheat via enhancing N supply and uptake.

Control Efficacy and Antifungal Mechanism of Bacillus Cereus Strain JK14 against Wheat Take-all Disease

[Objective] Study on control efficacy and inhibitory effect of Bacillus cereus strain JK14^·against wheat take-all disease, investigating its antifungal mechanism. [Method] B. cereus JK14^· was isolated from soil in the rhizosphere of wheat, inhibitory effects of whose nutrient solution form against Gaeumannomyces graminis var tritici strains 9862 and 9812 were measured in laboratory and then for its antifungal mechanism. The strain JK14^· with rifampicin and wheat take-all disease resistance was screened by increasing concentration of the two substrates, and colonization of JK14^·was studied. [Result] In pot experiment, the control effects of JK14^·, against 9862 and 9812 are 63% and 59%, respectively, which are higher than that of chemical fungicides, with 55% and 51% , respectively. JK14^· could deform mycelium and causes degradation of cell wall. And there are also dynamic change of JK14^· in root system. JK14^· on seed could extend to root along with seed germination and rooting, but per unit tissue mycelium number decreased gradually. [Conclusion] The results indicate some control efficacy of B. cereus strain JK14^· against wheat take-all disease.

Twice-split phosphorus application alleviates low-temperature impacts on wheat by improved spikelet development and setting

Extreme low-temperature incidents have become more frequent and severe as climate change intensifies.In HuangHuai-Hai wheat growing area of China,the late spring coldness occurring at the jointing-booting stage(the anther interval stage)has resulted in significant yield losses of winter wheat.This study attempts to develop an economical,feasible,and efficient cultivation technique for improving the low-temperature(LT)resistance of wheat by exploring the effects of twice-split phosphorus application(TSPA)on wheat antioxidant characteristics and carbon and nitrogen metabolism physiology under LT treatment at the anther interval stage using Yannong 19 as the experimental material.The treatments consisted of traditional phosphorus application and TSPA,followed by a-4℃ LT treatment and natural temperature(NT)control at the anther interval stage.Our analyses showed that,compared with the traditional application,the TSPA increased the net photosynthetic rate(P_(n)),stomatal conductance(Gs),and transpiration rate(T_(r))of leaves and reduced the intercellular carbon dioxide concentration(C_(i)).The activity of carbon and nitrogen metabolism enzymes in the young wheat spikes was also increased by the TSPA,which promoted the accumulation of soluble sugar(SS),sucrose(SUC),soluble protein(SP),and proline(Pro)in young wheat spike and reduced the toxicity of malondialdehyde(MDA).Due to the improved organic nutrition for reproductive development,the young wheat spikes exhibited enhanced LT resistance,which reduced the sterile spikelet number(SSN)per spike by 11.8%and increased the spikelet setting rate(SSR)and final yield by 6.0 and 8.4%,respectively,compared to the traditional application.The positive effects of split phosphorus application became more pronounced when the LT treatment was prolonged.

Effect of thermal processing and fermentation with Chinese traditional starters on characteristics and allergenicity of wheat matrix

Wheat allergy has become a serious health threat worldwide and its prevalence has increased alarmingly in the past few years.Factors such as food matrix and food processing may alter the structure of wheat proteins,and hence affect its allergenic properties.However,few reports have focused on the influence of Chinese traditional starter fermentation on wheat allergy.In this study,5 starters from different regions of China were used for fermentation,and protein characteristics were monitored by sodium dodecyl sulfate polyacrylamide gel electropheresis,and immunoreactivity analyzed by immunoassay with allergenic serum was obtained from New Zealand white rabbits.The allergenicity of steamed and baked matrices was also evaluated.The results showed that the allergenicity of wheat dough was basically increased at the beginning and then decreased during fermentation,but specific trends depend on different starters.With the progress of fermentation,especially as pH value decreased to 3.0-4.0,the allergenicity decreased significantly.Baking and steaming can reduce the allergenicity of wheat matrix,but fermentation is not a key factor affecting the allergenic activity of proteins.Our results can provide a theoretical basis for controlling wheat allergenicity in food proces sing or producing hypoallergenic food.

Winter wheat yield improvement by genetic gain across different provinces in China

The replacement of winter wheat varieties has contributed significantly to yield improvement worldwide,with remarkable progress in China.Drawing on two sets of data,production yield from the National Bureau of Statistics of China and experimental yield from literature,this study aims to(1)illustrate the increasing patterns of production yield among different provinces from 1978 to 2018 in China,(2)explore the genetic gain in yield and yield relevant traits through the variety replacement based on experimental yield from 1937 to 2016 in China,and(3)compare the yield gap between experimental yield and production yield.The results show that both the production and experimental yields significantly increased along with the variety replacement.The national annual yield increase ratio for the production yield was 1.67%from 1978 to 2018,varying from 0.96%in Sichuan Province to 2.78%in Hebei Province;such ratio for the experimental yield was 1.13%from 1937 to 2016.The yield gap between experimental and production yields decreased from the 1970s to the 2010s.This study reveals significant increases in some yield components consequent to variety replacement,including thousand-grain weight,kernel number per spike,and grain number per square meter;however,no change is shown in spike number per square meter.The biomass and harvest index consistently and significantly increased,whereas the plant height decreased significantly.

Creating large EMS populations for functional genomics and breeding in wheat

Wheat germplasm is a fundamental resource for basic research,applied studies,and wheat breeding,which can be enriched normally by several paths,such as collecting natural lines,accumulating breeding lines,and introducing mutagenesis materials.Ethyl methane sulfonate(EMS)is an alkylating agent that can effectively introduce genetic variations in a wide variety of plant species.In this study,we created a million-scale EMS population(MEP)that started with the Chinese wheat cultivars‘Luyan 128’,‘Jimai 38’,‘Jimai 44’,and‘Shannong 30’.In the M1 generation,the MEP had numerous phenotypical variations,such as>3,000 chlorophyll-deficient mutants,2,519 compact spikes,and 1,692 male sterile spikes.There were also rare mutations,including 30 independent tillers each with double heads.Some M1 variations of chlorophyll-deficiency and compact spikes were inheritable,appearing in the M2 or M3 generations.To advance the entire MEP to higher generations,we adopted a single-seed descendent(SSD)approach.All other seed composites of M2 were used to screen other agronomically important traits,such as the tolerance to herbicide quizalofop-P-methyl.The MEP is available for collaborative projects,and provides a valuable toolbox for wheat genetics and breeding for sustainable agriculture.

WPA1 encodes a vWA domain protein that regulates wheat plant architecture

Plant height,spike,leaf,stem and grain morphologies are key components of plant architecture and related to wheat yield.A wheat(Triticum aestivum L.)mutant,wpa1,displaying temperaturedependent pleiotropic developmental anomalies,was isolated.The WPA1 gene,encoding a von Willebrand factor type A(vWA)domain protein,was located on chromosome arm 7DS and isolated by map-based cloning.The functionality of WPA1 was validated by multiple independent EMS-induced mutants and gene editing.Phylogenetic analysis revealed that WPA1 is monocotyledon-specific in higher plants.The identification of WPA1 provides opportunity to study the temperature regulated wheat development and grain yield.

The first factor affecting dryland winter wheat grain yield under various mulching measures: Spike number

Water is the key factor limiting dryland wheat grain yield.Mulching affects crop yield and yield components by affecting soil moisture.Further research is needed to determine the relationships between yield components and soil moisture with yield,and to identify the most important factor affecting grain yield under various mulching measures.A long-term 9-yearifeld experiment in the Loess Plateau of Northwest China was carried out with three treatments:no mulch (CK),plastic mulch (M_(P)) and straw mulch (M_(S)).Yield factors and soil moisture were measured,and the relationships between them were explored by correlation analysis,structural equation modeling and significance analysis.The results showed that compared with CK,the average grain yields of M_(P) and M_(S) increased by 13.0and 10.6%,respectively.The average annual grain yield of the M_(P) treatment was 134 kg ha^(–1) higher than the M_(S) treatment.There were no significant differences in yield components among the three treatments (P<0.05).Soil water storage of the M_(S) treatment was greater than the M_(P) treatment,although the differences were not statistically signifiant.Soil water storage during the summer fallow period (SWSSF) and soil water storage before sowing (SWSS) of M_(S) were significantly higher than in CK,which increased by 38.5 and 13.6%,respectively.The relationship between M_(P) and CK was not statistically significant for SWSSF,but the SWSS in M_(P) was significantly higher than in CK.In terms of soil water storage after harvest (SWSH) and water consumption in the growth period(ET),there were no signi?cant differences among the three treatments.Based on the three analysis methods,we found that spike number and ET were positively correlated with grain yield.However,the relative importance of spike number to yield was the greatest in the M_(P )and M_(S) treatments,while that of ET was the greatest in CK.Suifcient SWSSF could indirectly increase spike number and ET in the three treatments.Based on these results,mulch can improve yield and soil water storage.The most important factor affecting the grain yield of dryland wheat was spike number under mulching,and ET with CK.These findings may help us to understand the main factors influencing dryland wheat grain yield under mulching conditions compared to CK.

A novel AgNPs/MOF substrate-based SERS sensor for high-sensitive on-site detection of wheat gluten

Gluten,known as the major allergen in wheat,has gained increasing concerns in industrialized countries,resulting in an urgent need for accurate,high-sensitive,and on-site detection of wheat gluten in complex food systems.Herein,we proposed a silver nanoparticles(AgNPs)/metal-organic framework(MOF)substrate-based surface-enhanced Raman scattering(SERS)sensor for the high-sensitive on-site detection of wheat gluten.The detection occurred on the newly in-situ synthesized AgNPs/MOF-modified SERS substrate,providing an enhancement factor(EF)of 1.89×10^(5).Benefitting from the signal amplification function of AgNPs/MOF and the superiority of SERS,this sensor represented high sensitivity performance and a wide detection range from 1×10^(-15)mol/L to 2×10^(-6)mol/L with a detection limit of 1.16×10^(-16)mol/L,which allowed monitoring the trace of wheat gluten in complex food system without matrix interference.This reliable sandwich SERS sensor may provide a promising platform for high-sensitive,accurate,and on-site detection of allergens in the field of food safety.

Spectral purification improves monitoring accuracy of the comprehensive growth evaluation index for film-mulched winter wheat

In order to further improve the utility of unmanned aerial vehicle(UAV)remote-sensing for quickly and accurately monitoring the growth of winter wheat under film mulching, this study examined the treatments of ridge mulching,ridge–furrow full mulching, and flat cropping full mulching in winter wheat.Based on the fuzzy comprehensive evaluation (FCE) method, four agronomic parameters (leaf area index, above-ground biomass, plant height, and leaf chlorophyll content) were used to calculate the comprehensive growth evaluation index (CGEI) of the winter wheat, and 14 visible and near-infrared spectral indices were calculated using spectral purification technology to process the remote-sensing image data of winter wheat obtained by multispectral UAV.Four machine learning algorithms, partial least squares, support vector machines, random forests, and artificial neural network networks(ANN), were used to build the winter wheat growth monitoring model under film mulching, and accuracy evaluation and mapping of the spatial and temporal distribution of winter wheat growth status were carried out.The results showed that the CGEI of winter wheat under film mulching constructed using the FCE method could objectively and comprehensively evaluate the crop growth status.The accuracy of remote-sensing inversion of the CGEI based on the ANN model was higher than for the individual agronomic parameters, with a coefficient of determination of 0.75,a root mean square error of 8.40, and a mean absolute value error of 6.53.Spectral purification could eliminate the interference of background effects caused by mulching and soil, effectively improving the accuracy of the remotesensing inversion of winter wheat under film mulching, with the best inversion effect achieved on the ridge–furrow full mulching area after spectral purification.The results of this study provide a theoretical reference for the use of UAV remote-sensing to monitor the growth status of winter wheat with film mulching.

Subsoil tillage enhances wheat productivity,soil organic carbon and available nutrient status in dryland fields

Tillage practices during the fallow period benefit water storage and yield in dryland wheat crops.However,there is currently no clarity on the responses of soil organic carbon(SOC),total nitrogen(TN),and available nutrients to tillage practices within the growing season.This study evaluated the effects of three tillage practices(NT,no tillage;SS,subsoil tillage;DT,deep tillage)over five years on soil physicochemical properties.Soil samples at harvest stage from the fifth year were analyzed to determine the soil aggregate and aggregate-associated C and N fractions.The results indicated that SS and DT improved grain yield,straw biomass and straw carbon return of wheat compared with NT.In contrast to DT and NT,SS favored SOC and TN concentrations and stocks by increasing the soil organic carbon sequestration rate(SOCSR)and soil nitrogen sequestration rate(TNSR)in the 0-40 cm layer.Higher SOC levels under SS and NT were associated with greater aggregate-associated C fractions,while TN was positively associated with soluble organic nitrogen(SON).Compared with DT,the NT and SS treatments improved soil available nutrients in the 0-20 cm layer.These findings suggest that SS is an excellent practice for increasing soil carbon,nitrogen and nutrient availability in dryland wheat fields in North China.

Characterization and distribution of novel alleles of the vernalization gene Vrn-A1 in Chinese wheat(Triticum aestivum L.) cultivars

The ability of wheat to adapt to a wide range of environmental conditions is determined mostly by allelic diversity among genes regulating vernalization requirement.Vrn-1 is a major regulator of this requirement.In this study,two novel alleles of Vrn-A1 were discovered in Chinese cultivars:vrn-A1n was identified in two landraces,Jiunong 2 and Ganchun 16,and Vrn-A1o was detected in Duanhongmangmai.Both novel alleles showed a linked duplication in the promoter region.The common copy of these two alleles was identical to the recessive allele vrn-A1.Compared with the recessive allele vrn-A1,the other copy of vrn-A1n contained a 54-bp deletion in the promoter region and the distinct copy of Vrn-A1o contained an11-bp deletion in the promoter region.In segregating populations in the greenhouse under nonvernalizing(20–25°C)and long-day(16 h light)conditions,plants with the novel vrn-A1n allele did not head earlier than those with the recessive vrn-A1 allele.However,plants that were either homozygous or heterozygous for the novel Vrn-A1o allele headed earlier than those with the recessive vrn-A1 allele.To identify the novel allele with the small-sized product and facilitate screening,a DNA marker for the novel dominant allele Vrn-A1o was designed.Analysis of the novel-allele distribution showed that two cultivars carrying the vrn-A1n allele were dispersed in the northwestern spring wheat zone,and 12 cultivars carrying the dominant Vrn-A1o allele were widely distributed in the northwestern spring wheat zone,Xinjiang winter and spring wheat zone,Yellow and Huai River valley winter wheat zone,and QinghaiTibetan Plateau spring and winter wheat zone.Our study identifies useful germplasm and a DNA marker for wheat breeding.

Changes in wheat protein digestibility and allergenicity: role of Pediococcus acidilactici XZ31 and yeast during dough fermentation

Wheat flour,as the most important source of food globally,is one of the most common causative agents of food allergy.This study aimed to investigate the effects of fermentation on wheat protein digestibility and allergenicity.Protein digestibility were evaluated using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and enzyme-linked immunosorbent assay.The effect of protein on intestinal permeability was investigated by Caco-2 cell monolayers.Co-culture fermentation with Pediococcus acidilactici XZ31 and yeast leads to improvement in digestibility of wheat protein compared to single strain fermentation.Fermentation leads to a decrease in albumin/globulin antigenicity and an increase in gluten R5 reactivity,with the most significant changes in the co-culture group.Digestion strengthen the decrease of protein antigenicity and counteracts the difference in antigenicity induced by fermentation between groups.However,pretreatment with P.acidilactici XZ31 reduces the amount of allergens across Caco-2 monolayer and attenuates the gluten-induced increase in permeability of Caco-2 cell monolayer by reducing actin polymerization and villous atrophy.Co-culture fermentation reduces gluten-induced cell monolayer damage to a greater extent than P.acidilactici XZ31 monoculture.These results gives valuable insight into the effects of P.acidilactici XZ31 fermentation on the allergenicity and toxicity of wheat proteins,which contribute to promoting the application of multi-strain leavening agent in hypoallergenic and gluten-free wheat products.

Involvement of the ABA-and H_(2)O_(2)-Mediated Ascorbate-Glutathione Cycle in the Drought Stress Responses of Wheat Roots

Abscisic acid(ABA),hydrogen peroxide(H_(2)O_(2)) and ascorbate(AsA)–glutathione(GSH)cycle are widely known for their participation in various stresses.However,the relationship between ABA and H_(2)O_(2) levels and the AsA–GSH cycle under drought stress in wheat has not been studied.In this study,a hydroponic experiment was conducted in wheat seedlings subjected to 15%polyethylene glycol(PEG)6000–induced dehydration.Drought stress caused the rapid accumulation of endogenous ABA and H_(2)O_(2) and significantly decreased the number of root tips compared with the control.The application of ABA significantly increased the number of root tips,whereas the application of H_(2)O_(2) markedly reduced the number of root tips,compared with that under 15%PEG-6000.In addition,drought stress markedly increased the DHA,GSH and GSSG levels,but decreased the AsA levels,AsA/DHA and GSH/GSSG ratios compared with those in the control.The activities of the four enzymes in the AsA–GSH cycle were also markedly increased under drought stress,including glutathione reductase(GR),ascorbate peroxidase(APX),monodehydroascorbate reductase(MDHAR)and dehydroascorbate reductase(DHAR),compared with those in the control.However,the application of an ABA inhibitor significantly inhibited GR,DHAR and APX activities,whereas the application of an H_(2)O_(2) inhibitor significantly inhibited DHAR and MDHAR activities.Furthermore,the application of ABA inhibitor significantly promoted the increases of H_(2)O_(2) and the application of H_(2)O_(2) inhibitor significantly blocked the increases of ABA,compared with those under 15% PEG-6000.Taken together,the results indicated that ABA and H_(2)O_(2) probably interact under drought stress in wheat;and both of them can mediate drought stress by modulating the enzymes in AsA–GSH cycle,where ABA acts as the main regulator of GR,DHAR,and APX activities,and H_(2)O_(2) acts as the main regulator of DHAR and MDHAR activities.

Assessment of immune responses and intestinal flora in BALB/c mice model of wheat food allergy via different sensitization methods

Increasing incidences showed that food allergies have attracted more and more attention from researchers.BALB/c mice were sensitized with wheat gluten combined with aluminum hydroxide adjuvant via intraperitoneal injection,transdermal sensitization,and oral gavage sensitization route.Results showed that all the three sensitization methods could induce allergic symptoms;increase the serum antibody(total immunoglobulin E(IgE),specific IgE,IgG,IgA)and histamine content;promote the secretion of Th2 cytokines(interleukin(IL)-4,IL-5,IL-13)and inflammatory factors(IL-6,IL-17 A,IL-10);and inhibit the production of Th1 cytokines(IFN-γ,IL-2).However,the allergic symptoms of mice sensitized by intraperitoneal injection were the most obvious among the three models.The level of serum antibodies in intraperitoneal injection group was significantly higher than control.Subsequently,16 S rRNA sequencing technology was used to analyze the intestinal flora of mice.The results showed that the abundance of Firmicutes in the wheat protein sensitized group was lower than that in the normal group,while the abundance of Bacteroidetes was higher,and Lactobacillus was the difference marker in normal group.Bacterial species diversity analysis showed that the species richness and diversity of intestinal flora in mice were decreased,the difference between mice induced by intraperitoneal injection and normal control group mice was the most significant.Taken together,these results show that among three sensitization methods used to build a mouse model with aluminum hydroxide as adjuvant,intraperitoneal injection is the comparably best way to build a mouse sensitization mode.

Genome-wide association study of grain micronutrient concentrations in bread wheat

Bread wheat(Triticum aestivum)is a staple food crop worldwide.The genetic dissection of important nutrient traits is essential for the biofortification of wheat to meet the nutritional needs of the world's growing population.Here,45,298 single-nucleotide polymorphisms(SNPs)from 55K chip arrays were used to genotype a panel of 768 wheat cultivars,and a total of 154 quantitative trait loci(QTLs)were detected for eight traits under three environments by genome-wide association study(GWAS).Three QTLs(qMn-3B.1,qFe-3B.4,and qSe-3B.1/qFe-3B.6)detected repeatedly under different environments or traits were subjected to subsequent analyses based on linkage disequilibrium decay and the P-values of significant SNPs.Significant SNPs in the three QTL regions formed six haplotypes for qMn-3B.1,three haplotypes for qFe-3B.4,and three haplotypes for qSe-3B.1/qFe-3B.6.Phenotypic analysis revealed significant differences among haplotypes.These results indicated that the concentrations of several nutrient elements have been modified during the domestication of landraces to modern wheat.Based on the QTL regions,we identified 15 high-confidence genes,eight of which were stably expressed in different tissues and/or developmental stages.TraesCS3B02G046100 in qMn-3B.1 and TraesCS3B02G199500 in qSe-3B.1/qFe-3B.6 were both inferred to interact with metal ions according to the Gene Ontology(GO)analysis.TraesCS3B02G199000,which belongs to qSe-3B.1/qFe-3B.6,was determined to be a member of the WRKY gene family.Overall,this study provides several reliable QTLs that may significantly affect the concentrations of nutrient elements in wheat grain,and this information will facilitate the breeding of wheat cultivars with improved grain properties.

Influences of fractional separation on the structure and reactivity of wheat straw cellulose for producing 5-hydroxymethylfurfural

High-efficient production of 5-hydroxymethylfurfural(HMF),a“sleeping giant”in sustainable chemistry,from cellulose depends significantly on the effective separation of cellulose from lignocellulosic biomass.Herein,we report the fractional separation of wheat straw cellulose(WSC)from wheat straw under solvothermal conditions using a mixed solvent of γ-valerolactone(GVL)and H_(2)O as the separating solvent,wherein the impacts of fractional separation parameters(solvent composition,temperature,and time)on removals of lignin and hemicellulose as well as purity and recovery of cellulose were studied by a Box-Behnken Design of response surface method.The optimization of the solvothermal parameters enabled an optimal fractional separation condition(V_(GVL):~60.0%,T:205℃,t:~1.7 h)that led to a higher purity(89.4%)and recovery(86.7%)of cellulose in WSC.A further correlation of the removals of lignin and hemicellulose as well as purity and recovery of cellulose with the yield of HMF excluded an independent influence of the above factors.Instead,a comprehensive contribution of high fractional separation efficiency(defined as the product of cellulose purity and recovery)and low crystallinity of WSC was found to improve the HMF yield.However,the heat-and freeze-dryings of WSC after the solvothermal separation were found to lower the HMF molar yield because it re-improved the crystallinity of WSC.A high HMF molar yield of 58.6%was achieved after reacting wet-WSC in a mixed solvent of 1,4-dioxane and H_(2)O at 180℃for 20 min,which was 1.5 fold higher than that from microcrystalline cellulose.This work highlights the importance of enhancing the fractional separation efficiency of cellulose from lignocellulosic biomass while avoiding the drying process for future HMF biorefinery.

The nitrogen transformation behavior based on the pyrolysis products of wheat straw

In order to provide basic design parameters for the industrial pyrolysis process,the transformation behavior of nitrogen was investigated using wheat straw as raw material.The distributions of nitrogen in pyrolysis char,oil,and gas were obtained and the nitrogenous components in the products were analyzed systematically by X-ray photoelectron spectroscopy(XPS),pyrolysis-gas chromatography/mass spectrometry(Py-GC/MS)and thermogravimetric-Fourier transform infrared spectrometry(TG-FTIR).The nitrogen distribution ranges of the pyrolysis char,oil,and gas were 37.34%–54.82%,32.87%–40.94%and 10.20%–28.83%,respectively.More nitrogen was retained in char at lower pyrolysis temperature and the nitrogen distribution of oil was from rise to decline with increasing temperature.The most abundant N-containing compounds in three-phase products were pyrrole-N,amines,and HCN,respectively.In addition,the transformation mechanism of nitrogen from wheat straw to pyrolysis products was concluded.

Heterogeneous population distribution enhances resistance to wheat lodging by optimizing the light environment

Lodging is still the key factor that limits continuous increases in wheat yields today,because the mechanical strength of culms is reduced due to low-light stress in populations under high-yield cultivation.The mechanical properties of the culm are mainly determined by lignin,which is affected by the light environment.However,little is known about whether the light environment can be sufficiently improved by changing the population distribution to inhibit culm lodging.Therefore,in this study,we used the wheat cultivar“Xinong 979”to establish a low-density homogeneous distribution treatment(LD),high-density homogeneous distribution treatment(HD),and high-density heterogeneous distribution treatment(HD-h)to study the regulatory effects and mechanism responsible for differences in the lodging resistance of wheat culms under different population distributions.Compared with LD,HD significantly reduced the light transmittance in the middle and basal layers of the canopy,the net photosynthetic rate in the middle and lower leaves of plants,the accumulation of lignin in the culm,and the breaking resistance of the culm,and thus the lodging index values increased significantly,with lodging rates of 67.5%in 2020–2021 and 59.3%in 2021–2022.Under HD-h,the light transmittance and other indicators in the middle and basal canopy layers were significantly higher than those under HD,and the lodging index decreased to the point that no lodging occurred.Compared with LD,the activities of phenylalanine ammonia-Lyase(PAL),4-coumarate:coenzyme A ligase(4CL),catechol-O-methyltransferase(COMT),and cinnamyl-alcohol dehydrogenase(CAD)in the lignin synthesis pathway were significantly reduced in the culms under HD during the critical period for culm formation,and the relative expression levels of TaPAL,Ta4CL,TaCOMT,and TaCAD were significantly downregulated.However,the activities of lignin synthesis-related enzymes and their gene expression levels were significantly increased under HD-h compared with HD.A partial least squares path modeling analysis found significant positive effects between the canopy light environment,the photosynthetic capacity of the middle and lower leaves of plants,lignin synthesis and accumulation,and lodging resistance in the culms.Thus,under conventional high-density planting,the risk of wheat lodging was significantly higher.Accordingly,the canopy light environment can be optimized by changing the heterogeneity of the population distribution to improve the photosynthetic capacity of the middle and lower leaves of plants,promote lignin accumulation in the culm,and enhance lodging resistance in wheat.These findings provide a basis for understanding the mechanism responsible for the lower mechanical strength of the culm under high-yield wheat cultivation,and a theoretical basis and for developing technical measures to enhance lodging resistance.