The study of Nitrogen fixation, uptake, and leaching at different soil depths in the co-cultivation of maize and soybean under phosphorus fertilization is important for sustainable agriculture. This study was conducte...The study of Nitrogen fixation, uptake, and leaching at different soil depths in the co-cultivation of maize and soybean under phosphorus fertilization is important for sustainable agriculture. This study was conducted in Quzhou, Hebei Province, China, with MC812 maize and Jidou12 soybean varieties. Soil samples were taken from each plot to create a composite sample. The results show that nitrogen concentration varies at different depths and is higher in all treatments between 40 and 100 cm. Incorporating intercropping of maize and soybeans into farming practices can lead to more sustainable and environmentally friendly agriculture in China.展开更多
Intercropping, particularly the combination of maize and soybeans, has been widely recognized for its potential to improve nitrogen uptake and promote sustainable agriculture. This study examines the patterns of nitro...Intercropping, particularly the combination of maize and soybeans, has been widely recognized for its potential to improve nitrogen uptake and promote sustainable agriculture. This study examines the patterns of nitrogen uptake in maize and soybean intercropping systems under different growth stages and phosphorus fertilization levels and investigates the influence of nitrogen uptake on growth parameters such as plant height, leaf area, and biomass accumulation in the maize/soybean intercrop under different phosphorus fertilization regimes. The study also collected chlorophyll samples at different growth stages of maize in monoculture and intercropping with maize or soybean. The results showed that plant height was greater in V10 in both fertilized and unfertilized treatments for intercropped maize and soybean, and chlorophyll concentration was higher in VT intercropped maize. The results also showed a higher accumulation of biomass. Understanding the growth dynamics of these plants in monoculture and intercropping systems and the impact of fertilization practices is crucial for optimizing crop productivity and sustainability in agricultural systems.展开更多
Root architecture,which determines the water and nutrient uptake ability of crops,is highly plastic in response to soil environmental changes and different cultivation patterns.Root phenotyping for field-grown crops,e...Root architecture,which determines the water and nutrient uptake ability of crops,is highly plastic in response to soil environmental changes and different cultivation patterns.Root phenotyping for field-grown crops,especially topological trait extraction,is rarely performed.In this study,an image-based semi-automatic root phenotyping method for field-grown crops was developed.The method consisted of image acquisition,image denoising and segmentation,trait extraction and data analysis.Five global traits and 40 local traits were extracted with this method.A good consistency in 1st-order lateral root branching was observed between the visually counted values and the values extracted using the developed method,with R^(2)=0.97.Using the method,we found that the interspecific advantages for maize mainly occurred within 5 cm from the root base in the nodal roots of the 5th-7th nodes,and that the obvious inhibition of soybean was mostly reflected within 20 cm from the root base.Our study provides a novel approach with high-throughput and high-accuracy for field research on root morphology and branching features.It could be applied to the 3D reconstruction of field-grown root system architecture to improve the inputs to data-driven models(e.g.,OpenSimRoot)that simulate root growth,solute transport and water uptake.展开更多
Flavonoids produced by legume roots act as signaling molecules that induce the expression of nod genes in symbiotic rhizobia.However,the role of flavonoids in root exudates under intercropping systems in promoting soy...Flavonoids produced by legume roots act as signaling molecules that induce the expression of nod genes in symbiotic rhizobia.However,the role of flavonoids in root exudates under intercropping systems in promoting soybean nodulation remains unclear.Two consecutive years of field experiments were conducted using maize–soybean strip intercropping with interspecific row spacings of 30 cm(MS30),45 cm(MS45),and 60 cm(MS60),along with sole cropping of soybean(SS)and maize(MM).Root interactions were manipulated using either no root barrier(NB)or a polyethylene plastic barrier(PB)to assess the relationship between flavonoids in root exudates and soybean nodulation.We found that root–root interaction between soybean and maize increased nodule number and fresh weight in intercropped soybean,with enhancement gradually increasing as interspecific distance widened.The proportion of nodules with diameters exceeding 0.4 cm was higher in intercropped soybean under NB compared to PB.Additionally,the expression of nodule-related genes-GmENOD40,Gm NIN2b,and Gm EXPB2-was up-regulated.Furthermore,compared to monocropping,isoflavone secretion by soybean roots decreased,whereas flavonoid and flavonol secretion by both maize and soybean roots increased under intercropping.The abundance of differentially secreted flavonoid metabolites in the rhizosphere of both species declined when root contact was prevented by the barrier.In soybean roots,the expression of Gm CHS8 and Gm IFS1 was up-regulated,while Gm ICHG was down-regulated under root interaction.Most flavonoid and flavonol compounds showed positive correlations with nodule diameter.Nodule number,fresh weight,and the proportion of nodules larger than 0.2 cm increased in diverse soybean genotypes treated with maize root exudates,which contributed to enhanced nitrogen fixation capacity.Therefore,maize–soybean strip intercropping,combined with optimal row spacing,enhances the positive effects of underground root interactions and improves nodulation and nitrogen fixation in intercropped soybean.展开更多
Maize/soybean intercropping systems are commonly used in developing countries,but few studies have been performed to elucidate the differences in nutrient efficiency and rhizosphere microbiome,especially when maize is...Maize/soybean intercropping systems are commonly used in developing countries,but few studies have been performed to elucidate the differences in nutrient efficiency and rhizosphere microbiome,especially when maize is intercropped with different soybean varieties.In this study,field experiments were conducted to compare the growth and yield of two soybean(Glycine max)varieties,BD2 and YC03-3,and one maize(Zea mays)variety,Huazhen,in mono-cropped and intercropped cultures.The plant biomass and N content of both crops in BD2/maize intercropping were significantly improved compared to their monoculture,but no such effects were observed in the plants of YC03-3/maize intercropping.The yield of BD2 intercropped with maize exhibited a 37.5%increment above that of BD2 in monoculture.Moreover,19.2-29.1%longer root length of maize and 19.0-39.4%larger root volume of BD2 were observed in BD2/maize intercropping than in monoculture,but no growth advantage was observed in YC03-3/maize intercropping.Maize showed root avoidance when intercropped with BD2,but space competition when intercropped with YC03-3.16S rRNA amplicon sequencing showed that compared with the monoculture system,rhizobacteria community composition in BD2/maize intercropping changed more significantly than that of the YC03-3/maize intercropping system.In BD2/maize intercropping,most of the rhizobacteria community biomarker bacteria of BD2 were positively correlated with plant biomass,as well as plant P and N content.Maize tended to recruit Rhizobiales and Proteobacteria,which showed positive correlation with plant biomass and N content,respectively,as well as soil available N.In conclusion,soybean varieties determined the advantages of maize/soybean intercropping through root-root interactions and modification of rhizobacteria communities.Our insight emphasizes a linkage between root traits and the rhizobacteria community,which shows the importance of optimizing intercropping systems by selection of appropriate crop varieties.展开更多
Betalain,an economically valuable water-soluble natural plant pigment,is prized for its strong antioxidant activity,making it popular as a dietary supplement and a visual marker for plant transformation.However,market...Betalain,an economically valuable water-soluble natural plant pigment,is prized for its strong antioxidant activity,making it popular as a dietary supplement and a visual marker for plant transformation.However,market demand significantly outstrips current production capacity.This study reports the development of an efficient push-and-pull multigene strategy based on polycistronic expression and metabolic flux regulation to enhance betalain biosynthesis in transgenic maize(Zea mays L.)endosperm.We engineered a novel enhanced RUBY(eRUBY)system derived from the original polycistronic RUBY construct(CYP76AD1P2ADODA1P2ADOPA5GT unit,abbreviated CDG)by introducing arogenate dehydrogenase(ADHα)to increase the L-tyrosine substrate supply.All the genes were driven by the endosperm-specific promoter.Fusion of ADHαinto a single polycistronic eRUBY construct(CDGA)produced significantly higher betanin(6.88 mg g−1 dry weight)and isobetanin(1.81 mg g−1 dry weight)levels than in CDG+A,which stacked the ADHαcassette independently with CDG.The high betalain accumulation in CDGA lines(which also exhibited higher transgene copy number)resulted in a 2.85–7.58-fold improvement in endosperm antioxidant capacity compared to WT(versus 2.48–2.80-fold in CDG+A).Importantly,transgenic plants maintained a normal phenotype.Transcriptome and metabolome analyses further indicated that metabolism of phenylalanine,alanine,aspartate,and glutamate contributes to betalain production.Hybridization with sweet corn successfully created a high-sugar eRUBY maize variety.Collectively,these results demonstrate the successful development of a novel maize germplasm with significantly enhanced nutritional value through high betalain accumulation.展开更多
Maize(Zea mays L.)is recognized as one of the most significant cereal crops worldwide,serving as a primary source of human food,animal feed,and industrial raw materials.With increasing diversification of market demand...Maize(Zea mays L.)is recognized as one of the most significant cereal crops worldwide,serving as a primary source of human food,animal feed,and industrial raw materials.With increasing diversification of market demands for specialty maize varieties,distinctive fresh produce cultivars characterized by unique textures have gained considerable popularity among consumers(Boyer and Shannon 1984).Notably,sweet maize is often referred to as the‘King of fruits and vegetables'due to its richness in polysaccharides,dietary fiber,trace elements,vitamins,linoleic acid,and other essential nutrients(Revilla et al.2021).展开更多
Maize yield is critically endangered by diseases throughout its growth cycle,posing significant risks to food security.The spatial and temporal dynamics of maize yield loss and the rate of yield loss attributable to t...Maize yield is critically endangered by diseases throughout its growth cycle,posing significant risks to food security.The spatial and temporal dynamics of maize yield loss and the rate of yield loss attributable to these threats on a regional scale have been challenging to ascertain due to scarce continuous observation data.This study compiled county-level data on maize yield and yield loss across China's six primary cropping regions over twenty years from 1999 to 2018.These include the Spring-sown area of Northern China(1-NC),the Summer-sown Huang-Huai-Hai Plain(2-HHP),the Southwest Mountain(3-SM),the Southern Hilly(4-SH),the Northwest Irrigated(5-NI),and the Qinghai-Tibet Plateau Maize Regions(6-QTP).We identified 15 major diseases affecting these regions.The annual average yield loss due to maize diseases in the regions 1-NC,2-HHP,3-SM,4-SH,5-NI,and 6-QTP were 0.40,0.58,0.12,0.05,0.04 and<0.01 million tons,respectively,and the corresponding average yield loss rate(the ratio of yield loss to total yield)in these regions was 0.63,0.90,0.65,0.63,0.44,and 0.05.The yield loss due to all diseases increased for three regions in 3-SM,4-SH and 5-NI.The yield loss rate due to diseases significantly increased in region 4-SH and 5-NI.Predominantly,maize leaf blight has become the most significant threats.In region 1-NC,maize head smut(D1)and maize leaf blight(D2)were the primary diseases.In region 2-HHP,maize leaf blight(D2),maize rust(D3),maize brown spot(D5),Curvularia leaf spot(D7),and maize virus disease(D14)were the key pathogens.Bivariate trend analysis(joint analysis of yield loss and loss rate trends)indicated that maize head smut(D1)decreased significantly in 1-NC,while in 2-HHP,six diseases showed a significant decrease in both yield loss and loss rate,namely sheath blight(D4),brown spot(D5),root rot(D11),downy mildew(D12)and virus disease(D14).By providing a long-term,national-scale perspective,this study not only supports the development of broad management strategies but also guides the creation of precise,region-specific control protocols to safeguard maize production.展开更多
Persistent overcast rain was an essential limiting factor for summer maize production,of which immediate impact was the dual pressure of waterlogging and shading.However,the mechanisms underlying independent and combi...Persistent overcast rain was an essential limiting factor for summer maize production,of which immediate impact was the dual pressure of waterlogging and shading.However,the mechanisms underlying independent and combined effects of waterlogging and shading on maize yield losses remain understudied,particularly across different growth stages.Denghai 605(DH605)was selected to be subjected shading,waterlogging,and their combined stress at the 3rd leaf stage(V3),the 6th leaf stage(V6),and tasseling stage(VT).Results showed that shading,waterlogging and their combination significantly restricted leaf area expansion,reduced leaf net photosynthetic rate(P_(n))and net assimilation rate(NAR),thereby decreasing the crop growth rate(CGR)and biomass accumulation.Additionally,compared to control,the process of lignin synthesis was inhibited under stressed treatment,resulting in diminished stem mechanical strength and impaired vascular system development,which substantially reduced assimilate remobilization efficiency to the ear and ultimate grain yield.Waterlogging and combined stresses exhibited maximum impact at the V3 stage,followed by V6 and VT stages,while shading effects were most pronounced at the VT stage,followed by V6 and V3 stages.Moreover,the compound stress exacerbated the damage brought about by a single stress.As climate change is projected to increase the frequency of multiple abiotic stress occurrences,these findings provide valuable insights for future summer maize breeding research under persistent rainfall conditions.展开更多
Anther is a key male reproductive organ that is essential for the plant life cycle,from the sporophyte to the gametophyte generation.To explore the isoform-level transcriptional landscape of developing anthers in maiz...Anther is a key male reproductive organ that is essential for the plant life cycle,from the sporophyte to the gametophyte generation.To explore the isoform-level transcriptional landscape of developing anthers in maize(Zea mays L.),we analyzed Iso-Seq data from anthers collected at 10 developmental stages,together with strand-specific RNA-seq,CAGE-seq,and PAS-seq data.Of the 152,026 high-confidence full-length isoforms identified,68.8%have not been described;these include 22,365 isoforms that originate from previously unannotated loci and 82,167 novel isoforms that originate from annotated protein-coding genes.Using our newly developed strategy to detect dynamic expression patterns of isoforms,we identify 13,899 differentially variable regions(DVRs);surprisingly,1275 genes contain more than two DVRs,revealing highly efficient utilization of limited genic regions.We identify 7876 long non-coding RNAs(lncRNAs)from 4098 loci,most of which were preferentially expressed during cell differentiation and meiosis.We also detected 371 long-range interactions involving intergenic lncRNAs(lincRNAs);interestingly,243 were lincRNA-gene ones,and the interacting genes were highly expressed in anthers,suggesting that many potential lncRNA regulators of key genes are required for anther development.This study provides valuable resources and fundamental information for studying the essential transcripts of key genes during anther development.展开更多
α.-Zeins,the major maize endosperm storage proteins,are transcriptionally regulated by Opaque2(O2)and prolamin-box-binding factor 1(PBF1),with Opaque11(O11)functioning upstream of them.However,whether O11 directly bi...α.-Zeins,the major maize endosperm storage proteins,are transcriptionally regulated by Opaque2(O2)and prolamin-box-binding factor 1(PBF1),with Opaque11(O11)functioning upstream of them.However,whether O11 directly binds toα-zein genes and its regulatory interactions with O2 and PBF1 remain unclear.Using the small-kernel mutant sw1,which exhibits decreased 19-kDa and increased 22-kDaα-zein,we positionally clone O11 and find it directly binds to G-box/E-box motifs.O11 activates 19-kDaα-zein transcription,stronger than PBF1 but weaker than O2.Notably,PBF1 competitively binds to an overlapping E-box/P-box motif,and represses O11-mediated transactivation.Although O11 does not physically interact with O2,it participates in the O2-centered hierarchical network to enhanceα-zein expression.sw1 o2 and sw1 pbf1 double mutants exhibit smaller,more opaque kernels with further reduced 19-kDa and 22-kDaα-zeins compared to the single mutants,suggesting distinct regulatory effects of these transcription factors on 19-kDa and 22-kDaα-zein genes.Promoter motif analysis suggests that O11,PBF1,and O2 directly regulate 19-kDaα-zein genes,while O11 indirectly controls 22-kDaα-zein genes via O2 and PBF1 modulation.These findings identify the unique and coordinated roles of O11,O2,and PBF1 in regulatingα.-zein genes and kernel development.展开更多
There is increasing interest in developing reduced-crude protein(CP)diets for broiler chickens because their commercial adoption would generate a diverse range of advantages that would enhance the sustainability of th...There is increasing interest in developing reduced-crude protein(CP)diets for broiler chickens because their commercial adoption would generate a diverse range of advantages that would enhance the sustainability of the chickenmeat industry.However,the development of reduced-CP broiler diets is proving to be not straightforward,particularly when dietary CP reductions exceed 30 g/kg.The capacity of broilers to accommodate dietary CP reductions when offered maize-based diets is superior to their counterparts offered wheat-based diets.Numerous factors could be contributing to this difference but have yet to be identified with certainty.Maize-based,reduced-CP diets characteristically support better weight gains and efficiencies of feed conversion than wheat-based diets,but this better growth performance is associated with increased fat deposition,monitored as heavier relative abdominal fat-pad weights.This is an intriguing dichotomy.Insulin is a powerful anabolic hormone in mammalian species capable of promoting fat deposition,protein accretion and growth,but the importance of insulin in avian species is usually dismissed.This is because broiler chickens are considered both hyperglycaemic and resistant to insulin.However,the likelihood is that young broiler chickens are more sensitive to insulin than is generally recognised and the anabolic properties of insulin may be contributing to the diverse responses observed between maize and wheat in the context of reduced-CP diets.Dietary CP reductions may trigger increased plasma ammonia concentrations and metabolic acidosis,but both factors can influence insulin secretion and insulin resistance.Maize has slower rates of starch digestion and glucose absorption than wheat and it has been suggested that this generates a more sustained insulin release resulting in increased weight gains and fat deposition.If so,this could be driving the differences generated by the feed grain selected as the basis of reduced-CP diets.The intention of this review is to explore this proposition because if the causal factors of the differences between maize and wheat can be identified the development and acceptance of reduced-CP broiler diets should be accelerated.展开更多
High temperature stress (HT) significantly reduces maize yield by impairing starch accumulation in kernels.However,the mechanism by which HT affects starch synthesis remains controversial-whether through reduced assim...High temperature stress (HT) significantly reduces maize yield by impairing starch accumulation in kernels.However,the mechanism by which HT affects starch synthesis remains controversial-whether through reduced assimilate supply or direct inhibition on kernel metabolism.To clarify these mechanisms,a heat-sensitive maize hybrid,Xianyu 335 (XY),was exposed to 30℃/20℃ (maximum/minimum temperature,control) and 40℃/30℃ for seven consecutive days during the seed setting stage.Synchronous pollination (SP),apical pollination (AP),and shading treatments were applied to manipulate the inherent source–sink ratio in maize plants.Results showed that apical kernel weight decreased by 11.9%under 40℃ in the SP treatment.The ^(13)C content,starch accumulation,and cell-wall invertase (CWIN) activity also declined by 15.9,36.7,and 16.4%,respectively,under HT.In the shading treatment,40℃/30℃ caused even greater reductions in^(13)C content,starch accumulation,and CWIN activity due to diminished assimilate supply.Conversely,in the AP treatment,starch content and CWIN activity increased by 22.0 and 18.5%,respectively,under 40℃/30℃,resulting in kernel weight and ^(13)C content similar to those in SP and shading treatments regardless of temperature.Consistent with apical kernels under AP,HT did not negatively affect middle kernels in either SP or shading treatments,as kernel weight and starch content remained unchanged under HT.Although all kernels were exposed to the same HT or control environment,their responses varied a lot.The impaired starch synthesis in apical kernels under HT was rescued by increasing carbon supply via AP treatment.The contrasting performance among middle kernels,apical kernels under AP,and apical kernels under SP or shading indicates that reduced carbon supply is a critical factor underlying inhibited starch accumulation.Our findings provide a theoretical basis for further understanding kernel abortion under HT.展开更多
In maize production,the development of density-tolerant and lodging-resistant varieties has made dense planting an effective strategy for achieving high and stable yields,with superior hybrids serving as a prerequisit...In maize production,the development of density-tolerant and lodging-resistant varieties has made dense planting an effective strategy for achieving high and stable yields,with superior hybrids serving as a prerequisite for successful highdensity cultivation.However,the photosynthetic mechanisms underlying improved density tolerance in maize hybrids released across different eras in China remain unclear.This study investigates 40 years of breeding progress toward enhanced photosynthetic traits under varying planting densities and elucidates the physiological and ecological bases of improved density tolerance in maize hybrids.A three-year field experiment was conducted from 2019 to 2021 to compare eight major Chinese hybrids from four decadal cohorts under three planting densities:45,000(D1),67,500(D2),and 90,000(D3)plants ha^(-1).At high density(D3),modern hybrids exhibited a more optimal canopy architecture and superior leaf photosynthetic performance compared to older hybrids,despite a slight reduction in specific leaf nitrogen.Notably,modern hybrids(2000s)were able to maintain higher net photosynthetic rates and photosynthetic nitrogen use efficiency(PNUE)at D3,resulting in the highest grain yield(GY),which was 118.47%greater than that of older hybrids(1970s).Leaf area duration after anthesis,total chlorophyll content,key photosynthetic enzyme activities,and maximum quantum efficiency of PSII photochemistry were all positively correlated with GY.Among these,PNUE showed the strongest correlation with grain yield and thus represents a key indicator for optimizing maize hybrids.Based on these findings,breeders should continue selecting hybrids under high-density and suboptimal conditions,focusing on optimizing population architecture and enhancing photosynthetic capacity while fine-tuning leaf nitrogen status to develop high-yielding,density-tolerant hybrids capable of sustaining long-term increases in maize grain yield.展开更多
The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new con...The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new concept of deep storage irrigation through flood resources utilization.However,whether deep storage irrigation can recharge deep soil moisture and sustain crop production still requires further study.A two-year field experiment was conducted on summer maize in the Guanzhong Plain with five soil wetting layer depths(T1:60 cm;T2:90 cm;T3:120 cm;T4:150 cm;T5:180 cm)and soil saturation moisture content as the irrigation upper limit.The results presented that the ranges of deep soil moisture recharge in the100–200 cm soil profile(SMS_(100–200))was 73.34–267.42 and 0–150.03 mm in 2021(wet season)and 2022(normal season).When the effective precipitation and irrigation exceeded 390 mm,the SMS_(100–200)began to linearly increase.The highest grain yield(GY)were observed at T2 and T3 treatments in 2021(11.44 t ha^(-1))and 2022(11.25 t ha^(-1)),respectively.The maize GY of T4 in 2021 and T5 in 2022 were only 3.9 and 5.7%lower than the maximize GY,respectively.However,the SMS_(100–200)for T4 and T5 were 2.4 and 5.0 times that of T2 and T3 treatments in 2021 and 2022,respectively.Overall,the further increase in irrigation amounts induced only a slight decrease in grain yield,but it significantly increased deep soil moisture recharge.Therefore,the deep storage irrigation breaks through the traditional idea of water-saving irrigation with limited water resources,which can be utilized as an effective alternative to address the issues of water scarcity,low flood resources utilization,and groundwater level declines in the irrigation districts of northern China.展开更多
Carbohydrate partitioning from source to sink tissues is essential for plant growth and development.However,in maize(Zea mays L.),the molecular mechanisms by which callose synthase genes regulate this process remain l...Carbohydrate partitioning from source to sink tissues is essential for plant growth and development.However,in maize(Zea mays L.),the molecular mechanisms by which callose synthase genes regulate this process remain largely unexplored.This study demonstrates that mutation of maize callose synthase12(Zm Cals12)results in increased carbohydrate accumulation in photosynthetic leaves but decreased carbohydrate content in sink tissues,leading to plant dwarfing and male sterility.Histochemical β-glucuronidase(GUS)activity assay and m RNA in situ hybridization(ISH)revealed that Zm Cals12 expression mainly occurs in the vascular transport system.Zm Cals12 loss-of-function decreased callose synthase activity and callose deposition in plasmodesmatas(PDs)and surrounding phloem cells(PCs)of the vascular bundle.The drop-and-see(DANS)assay indicated reduced PD permeability in photosynthetic cells and diminished transport competence of leaf veins in Zmcals12 mutants,resulting in decreased symplastic transport.Paraffin section analysis revealed that less-developed vascular cells(VCs)in Zmcals12 mutants likely disrupted sugar transport,contributing to the pleiotropic phenotype.Furthermore,impaired sugar transport inhibited internode development by suppressing auxin(IAA)biosynthesis and signaling in Zmcals12 mutant.These findings elucidate the mechanism by which Zm Cals12-mediated callose deposition and symplastic transport regulate maize growth and development.展开更多
Sand dust belts span approximately one-fifth of the global land surface.In these regions,dust tends to settle on vegetation surfaces,altering the observed reflectance and affecting remote sensing detections.To enhance...Sand dust belts span approximately one-fifth of the global land surface.In these regions,dust tends to settle on vegetation surfaces,altering the observed reflectance and affecting remote sensing detections.To enhance the accuracy of maize growth monitoring in dust-affected regions,this study aims to quantify the effect of sand dust retention on maize during the tasseling stage in the Kashgar Prefecture,Xinjiang Uygur Autonomous Region,China,by analyzing changes in canopy reflectance and vegetation indices.First,field sampling was conducted to measure the key canopy structure parameters and dust retention levels of maize,and laboratory spectral measurements were performed on leaf spectral properties under gradient dust retention.The measured data were then used to drive the LargE-Scale remote sensing data and image Simulation framework(LESS)model for simulating realistic maize canopy spectra across different dust levels,with validation against Sentinel-2 imagery.Second,on the basis of the simulated and satellite-derived spectra,the dust resistance of 36 common vegetation indices was systematically evaluated,and new robust dust-resistant indices were developed.The results showed that compared with dust-free maize,the canopy reflectance of dust-retained maize followed an increase–decrease–increase pattern,with critical turning points at 735 and 1325 nm.The maximum reflectance difference of–0.11755(change rate:29.002%)occurred within the 735–1325 nm range at 24 g/m^(2)dust retention,and the minimum reflectance difference of 0.04285(change rate:148.950%)was observed in the 350–735 nm range under the same dust retention level.Among the 36 vegetation indices,only the global environment monitoring index(GEMI)and the ratio of transformed chlorophyll absorption in reflectance index to optimized soil-adjusted vegetation index(TCARI/OSAVI)exhibited dust resistance,with GEMI being effective below 6 g/m^(2)and TCARI/OSAVI remaining stable across all levels(average ratio:0.970).The newly developed indices in this study,(RE3–RE2)/(NIR–RE2),(RE3–RE2)/(RE4–RE2),and(NIR–RE2)/(RE4–RE2),retained values within the predefined dust-resistant range over the full dust retention levels of 0–24 g/m^(2),thus showing a more stable dust resistance compared with the commonly used 36 vegetation indices.Specially,(RE3–RE2)/(RE4–RE2)performed the most robustly in Sentinel-2 imagery,that is,58.020%of pixels were within the dust-resistant range,and an average ratio of 0.937 was obtained for the original-spectra index.This study provides a scientific basis for crop monitoring and management in dust-affected regions.展开更多
The exogenous plant growth regulator,diethyl aminoethyl hexanoate(DA-6),in combination with suitable varieties and planting densities,is important to increase yield in the maize-soybean strip intercropping system.To i...The exogenous plant growth regulator,diethyl aminoethyl hexanoate(DA-6),in combination with suitable varieties and planting densities,is important to increase yield in the maize-soybean strip intercropping system.To identify the role of DA-6 in mitigating high-density stress and increasing yield,we conducted a two-year field experiment examining changes in branching architecture and other yield traits of soybeans in maize-soybean strip intercropping systems.In the planting system,two soybean cultivars(ND:Nandou 25 and QH:Qihuang 34)were grown under three planting densities(D1:102,000 plants ha^(-1),D2:130,000 plants ha^(-1),D3:158,000 plants ha^(-1))with DA-6 treatments(DA0:water control;DA60:60 mg L^(-1);DA100:100 mg L^(-1)).Applying DA-6 at 60 mg L^(-1)at the fourth trifoliolate leaf stage increased soybean yield,with QH yield rising by 22.4% and 29.5% at D3 density,and ND yield by 29.5% and 30.0% at D2 density in 2022 and 2023,respectively,compared with D1 under DA0.DA-6improved photosynthesis in both varieties under D2 density,with DA60 increasing ND canopy photosynthetic rate by 15.1%-16.4% and QG by 9.1%-20.6% over two years.In ND,DA-6 enhanced branching,raising the leaf area index by 37%,branch number from 3.6 to 4.7 per plant,and total pod number by 19.7%.In QH,yield grains were mainly due to a 17% increase in the number of stem pods and a 6.5% improvement in hundred-grain weight.In the maize-soybean strip intercropping system,QH achieved a high yield by forming a high-density(D2 to D3)main stem pod,and ND by combining moderate density(D1 to D2)with DA-6-induced branching.展开更多
[Objective] The experiment was aimed to explore character variation between different families after DNA introduction and select variant plants with good stability. [Method] The method of pollen-tube-pathway was used ...[Objective] The experiment was aimed to explore character variation between different families after DNA introduction and select variant plants with good stability. [Method] The method of pollen-tube-pathway was used to introduce total DNA of soybean into normal maize inbred line 7313 for selecting generation by generation. When field characters of maize, grain colors, grain traits and panicle axis colors were stable, the crude protein, gliadin, glutelin and oil content of grains which were selected from variant strains were detected and compared. [Result] The grain crude protein, gliadin, glutelin and oil content of line 26h-4-3 were significantly different from these of control treatment. The increments of D3 and D4 generation were 10.34% and 26.70%, 6.58% and 6.28%, 15.09% and 70.34%, 55.82% and 51.52% respectively. All indexes of line 26h-3-1 were also higher than these of control treatment and the increments of D3 and D4 generation were 5.67% and 21.63%,1.91% and 2.31%, 10.85% and 62.27%,22.49% and 9.67%. [Conclusion] The crude protein, gliadin, glutelin and oil content of variant line 26h-4-3 and 26h-3-1 were stable, so variant line 26h-4-3 and 26h-3-1 were excellent variant strains which satisfied the requirement of high protein breeding.展开更多
The effects of different maize sowing dates and densities on stem and leaf morphological characters and yield of soybean in wheat/maize/soybean relaycropping system were studied. The results showed that with early sow...The effects of different maize sowing dates and densities on stem and leaf morphological characters and yield of soybean in wheat/maize/soybean relaycropping system were studied. The results showed that with early sowing of maize, the maize yield was promoted, and maize was harvested in advance, which reduced the intergrowth period with soybean and guaranteed soybean＇s proper plant height, larger stem diameter and optimal values of LAI and SLW, so that soybean yield was also increased. The effects of different maize densities on the stem and leaf of soybean mainly were significant before the maize harvest, but soybean yield under high maize density was significantly lower than that under middle and low maize density, and the highest maize yield was under middle density. Based on soybean and maize comprehensive values, the optimum combination of this experiment was sowed on March 21 and planting density was 5.25×10^4 plant/hm^2.展开更多
文摘The study of Nitrogen fixation, uptake, and leaching at different soil depths in the co-cultivation of maize and soybean under phosphorus fertilization is important for sustainable agriculture. This study was conducted in Quzhou, Hebei Province, China, with MC812 maize and Jidou12 soybean varieties. Soil samples were taken from each plot to create a composite sample. The results show that nitrogen concentration varies at different depths and is higher in all treatments between 40 and 100 cm. Incorporating intercropping of maize and soybeans into farming practices can lead to more sustainable and environmentally friendly agriculture in China.
文摘Intercropping, particularly the combination of maize and soybeans, has been widely recognized for its potential to improve nitrogen uptake and promote sustainable agriculture. This study examines the patterns of nitrogen uptake in maize and soybean intercropping systems under different growth stages and phosphorus fertilization levels and investigates the influence of nitrogen uptake on growth parameters such as plant height, leaf area, and biomass accumulation in the maize/soybean intercrop under different phosphorus fertilization regimes. The study also collected chlorophyll samples at different growth stages of maize in monoculture and intercropping with maize or soybean. The results showed that plant height was greater in V10 in both fertilized and unfertilized treatments for intercropped maize and soybean, and chlorophyll concentration was higher in VT intercropped maize. The results also showed a higher accumulation of biomass. Understanding the growth dynamics of these plants in monoculture and intercropping systems and the impact of fertilization practices is crucial for optimizing crop productivity and sustainability in agricultural systems.
基金supported by the National Key Research and Development Program of China (2016YFD0300202)the Science and Technology Project of Yunna, China (2017YN07)the Science and Technology Major Project of Inner Mongolia, China (2019ZD024 and 2020GG0038)
文摘Root architecture,which determines the water and nutrient uptake ability of crops,is highly plastic in response to soil environmental changes and different cultivation patterns.Root phenotyping for field-grown crops,especially topological trait extraction,is rarely performed.In this study,an image-based semi-automatic root phenotyping method for field-grown crops was developed.The method consisted of image acquisition,image denoising and segmentation,trait extraction and data analysis.Five global traits and 40 local traits were extracted with this method.A good consistency in 1st-order lateral root branching was observed between the visually counted values and the values extracted using the developed method,with R^(2)=0.97.Using the method,we found that the interspecific advantages for maize mainly occurred within 5 cm from the root base in the nodal roots of the 5th-7th nodes,and that the obvious inhibition of soybean was mostly reflected within 20 cm from the root base.Our study provides a novel approach with high-throughput and high-accuracy for field research on root morphology and branching features.It could be applied to the 3D reconstruction of field-grown root system architecture to improve the inputs to data-driven models(e.g.,OpenSimRoot)that simulate root growth,solute transport and water uptake.
基金funded by the National Key Research and Development Program of China(2021YFF1000500)the National Natural Science Foundation of China(32372231)(3187101212)the earmarked fund for China Agriculture Research System(CARS-04-PS21)。
文摘Flavonoids produced by legume roots act as signaling molecules that induce the expression of nod genes in symbiotic rhizobia.However,the role of flavonoids in root exudates under intercropping systems in promoting soybean nodulation remains unclear.Two consecutive years of field experiments were conducted using maize–soybean strip intercropping with interspecific row spacings of 30 cm(MS30),45 cm(MS45),and 60 cm(MS60),along with sole cropping of soybean(SS)and maize(MM).Root interactions were manipulated using either no root barrier(NB)or a polyethylene plastic barrier(PB)to assess the relationship between flavonoids in root exudates and soybean nodulation.We found that root–root interaction between soybean and maize increased nodule number and fresh weight in intercropped soybean,with enhancement gradually increasing as interspecific distance widened.The proportion of nodules with diameters exceeding 0.4 cm was higher in intercropped soybean under NB compared to PB.Additionally,the expression of nodule-related genes-GmENOD40,Gm NIN2b,and Gm EXPB2-was up-regulated.Furthermore,compared to monocropping,isoflavone secretion by soybean roots decreased,whereas flavonoid and flavonol secretion by both maize and soybean roots increased under intercropping.The abundance of differentially secreted flavonoid metabolites in the rhizosphere of both species declined when root contact was prevented by the barrier.In soybean roots,the expression of Gm CHS8 and Gm IFS1 was up-regulated,while Gm ICHG was down-regulated under root interaction.Most flavonoid and flavonol compounds showed positive correlations with nodule diameter.Nodule number,fresh weight,and the proportion of nodules larger than 0.2 cm increased in diverse soybean genotypes treated with maize root exudates,which contributed to enhanced nitrogen fixation capacity.Therefore,maize–soybean strip intercropping,combined with optimal row spacing,enhances the positive effects of underground root interactions and improves nodulation and nitrogen fixation in intercropped soybean.
基金supported by the National Key Research and Development Program of China(2021YFF1000504 and 2023YFD1901300)the National Natural Science Foundation of China(32172658,32172659 and 32302662)the Natural Science Foundation of Guangdong Province,China(2021A1515010826).
文摘Maize/soybean intercropping systems are commonly used in developing countries,but few studies have been performed to elucidate the differences in nutrient efficiency and rhizosphere microbiome,especially when maize is intercropped with different soybean varieties.In this study,field experiments were conducted to compare the growth and yield of two soybean(Glycine max)varieties,BD2 and YC03-3,and one maize(Zea mays)variety,Huazhen,in mono-cropped and intercropped cultures.The plant biomass and N content of both crops in BD2/maize intercropping were significantly improved compared to their monoculture,but no such effects were observed in the plants of YC03-3/maize intercropping.The yield of BD2 intercropped with maize exhibited a 37.5%increment above that of BD2 in monoculture.Moreover,19.2-29.1%longer root length of maize and 19.0-39.4%larger root volume of BD2 were observed in BD2/maize intercropping than in monoculture,but no growth advantage was observed in YC03-3/maize intercropping.Maize showed root avoidance when intercropped with BD2,but space competition when intercropped with YC03-3.16S rRNA amplicon sequencing showed that compared with the monoculture system,rhizobacteria community composition in BD2/maize intercropping changed more significantly than that of the YC03-3/maize intercropping system.In BD2/maize intercropping,most of the rhizobacteria community biomarker bacteria of BD2 were positively correlated with plant biomass,as well as plant P and N content.Maize tended to recruit Rhizobiales and Proteobacteria,which showed positive correlation with plant biomass and N content,respectively,as well as soil available N.In conclusion,soybean varieties determined the advantages of maize/soybean intercropping through root-root interactions and modification of rhizobacteria communities.Our insight emphasizes a linkage between root traits and the rhizobacteria community,which shows the importance of optimizing intercropping systems by selection of appropriate crop varieties.
基金supported by grants from the Biological Breeding-National Science and Technology Major Project(2024ZD04077)the Invigorate the Seed Industry of Guangdong Province(2024-NPY-00-044)+3 种基金the National Natural Science Foundation of China(32272120)the Guangxi Science and Technology Major Project(GKAA24206023)the National Key Research and Development Program of China(2024YFF1000800)the Guangdong Basic Research Center of Excellence for Precise Breeding of Future Crops Major Project(FCBRCE-202502,FCBRCE-202504).
文摘Betalain,an economically valuable water-soluble natural plant pigment,is prized for its strong antioxidant activity,making it popular as a dietary supplement and a visual marker for plant transformation.However,market demand significantly outstrips current production capacity.This study reports the development of an efficient push-and-pull multigene strategy based on polycistronic expression and metabolic flux regulation to enhance betalain biosynthesis in transgenic maize(Zea mays L.)endosperm.We engineered a novel enhanced RUBY(eRUBY)system derived from the original polycistronic RUBY construct(CYP76AD1P2ADODA1P2ADOPA5GT unit,abbreviated CDG)by introducing arogenate dehydrogenase(ADHα)to increase the L-tyrosine substrate supply.All the genes were driven by the endosperm-specific promoter.Fusion of ADHαinto a single polycistronic eRUBY construct(CDGA)produced significantly higher betanin(6.88 mg g−1 dry weight)and isobetanin(1.81 mg g−1 dry weight)levels than in CDG+A,which stacked the ADHαcassette independently with CDG.The high betalain accumulation in CDGA lines(which also exhibited higher transgene copy number)resulted in a 2.85–7.58-fold improvement in endosperm antioxidant capacity compared to WT(versus 2.48–2.80-fold in CDG+A).Importantly,transgenic plants maintained a normal phenotype.Transcriptome and metabolome analyses further indicated that metabolism of phenylalanine,alanine,aspartate,and glutamate contributes to betalain production.Hybridization with sweet corn successfully created a high-sugar eRUBY maize variety.Collectively,these results demonstrate the successful development of a novel maize germplasm with significantly enhanced nutritional value through high betalain accumulation.
基金supported by the Youth Research Foundation of Beijing Academy of Agriculture and Forestry Sciences,China(QNJJ202420)the Beijing Science and Technology Association Youth Lifting Project,Chinathe Beijing Municipal Rural Revitalization Agricultural Science and Technology Development Project,China(NY2401020224)。
文摘Maize(Zea mays L.)is recognized as one of the most significant cereal crops worldwide,serving as a primary source of human food,animal feed,and industrial raw materials.With increasing diversification of market demands for specialty maize varieties,distinctive fresh produce cultivars characterized by unique textures have gained considerable popularity among consumers(Boyer and Shannon 1984).Notably,sweet maize is often referred to as the‘King of fruits and vegetables'due to its richness in polysaccharides,dietary fiber,trace elements,vitamins,linoleic acid,and other essential nutrients(Revilla et al.2021).
基金supported by the National Key Research and Development Program of China,China(2022YFF1301801)Agricultural scientific and technological innovation project of Shandong Academy of Agricultural Sciences,China(333 Project)(06202214442066)+1 种基金Beijing Natural Science Foundation,China(5232018)Technology Innovation Project of Shandong Academy of Agricultural Sciences,China(06202214442062).
文摘Maize yield is critically endangered by diseases throughout its growth cycle,posing significant risks to food security.The spatial and temporal dynamics of maize yield loss and the rate of yield loss attributable to these threats on a regional scale have been challenging to ascertain due to scarce continuous observation data.This study compiled county-level data on maize yield and yield loss across China's six primary cropping regions over twenty years from 1999 to 2018.These include the Spring-sown area of Northern China(1-NC),the Summer-sown Huang-Huai-Hai Plain(2-HHP),the Southwest Mountain(3-SM),the Southern Hilly(4-SH),the Northwest Irrigated(5-NI),and the Qinghai-Tibet Plateau Maize Regions(6-QTP).We identified 15 major diseases affecting these regions.The annual average yield loss due to maize diseases in the regions 1-NC,2-HHP,3-SM,4-SH,5-NI,and 6-QTP were 0.40,0.58,0.12,0.05,0.04 and<0.01 million tons,respectively,and the corresponding average yield loss rate(the ratio of yield loss to total yield)in these regions was 0.63,0.90,0.65,0.63,0.44,and 0.05.The yield loss due to all diseases increased for three regions in 3-SM,4-SH and 5-NI.The yield loss rate due to diseases significantly increased in region 4-SH and 5-NI.Predominantly,maize leaf blight has become the most significant threats.In region 1-NC,maize head smut(D1)and maize leaf blight(D2)were the primary diseases.In region 2-HHP,maize leaf blight(D2),maize rust(D3),maize brown spot(D5),Curvularia leaf spot(D7),and maize virus disease(D14)were the key pathogens.Bivariate trend analysis(joint analysis of yield loss and loss rate trends)indicated that maize head smut(D1)decreased significantly in 1-NC,while in 2-HHP,six diseases showed a significant decrease in both yield loss and loss rate,namely sheath blight(D4),brown spot(D5),root rot(D11),downy mildew(D12)and virus disease(D14).By providing a long-term,national-scale perspective,this study not only supports the development of broad management strategies but also guides the creation of precise,region-specific control protocols to safeguard maize production.
基金supported by the University Youth Innovation Science and Technology Support Program of Shandong Province,China(2021KJ073)the Postdoctoral Innovation Program of Shandong Province,China(202003039)+2 种基金the China Agriculture Research System(CARS-02-21)the State Key Laboratory of North China Crop Improvement and Regulation(NCCIR2023KF-8)the Key R&D Program of Shandong Province,China(2023TZXD08603)。
文摘Persistent overcast rain was an essential limiting factor for summer maize production,of which immediate impact was the dual pressure of waterlogging and shading.However,the mechanisms underlying independent and combined effects of waterlogging and shading on maize yield losses remain understudied,particularly across different growth stages.Denghai 605(DH605)was selected to be subjected shading,waterlogging,and their combined stress at the 3rd leaf stage(V3),the 6th leaf stage(V6),and tasseling stage(VT).Results showed that shading,waterlogging and their combination significantly restricted leaf area expansion,reduced leaf net photosynthetic rate(P_(n))and net assimilation rate(NAR),thereby decreasing the crop growth rate(CGR)and biomass accumulation.Additionally,compared to control,the process of lignin synthesis was inhibited under stressed treatment,resulting in diminished stem mechanical strength and impaired vascular system development,which substantially reduced assimilate remobilization efficiency to the ear and ultimate grain yield.Waterlogging and combined stresses exhibited maximum impact at the V3 stage,followed by V6 and VT stages,while shading effects were most pronounced at the VT stage,followed by V6 and V3 stages.Moreover,the compound stress exacerbated the damage brought about by a single stress.As climate change is projected to increase the frequency of multiple abiotic stress occurrences,these findings provide valuable insights for future summer maize breeding research under persistent rainfall conditions.
基金supported by the Excellent Young Scientists Fund(Category B)(32422063)the National Key Research and Development Program of China(2022YFF1003500)the Zhengzhou University Qiushi Postdoctoral Research Funding Program.For open access,the authors have applied for a Creative Commons Attribution(CC BY)license for any Author Accepted Manuscript version arising from this submission.
文摘Anther is a key male reproductive organ that is essential for the plant life cycle,from the sporophyte to the gametophyte generation.To explore the isoform-level transcriptional landscape of developing anthers in maize(Zea mays L.),we analyzed Iso-Seq data from anthers collected at 10 developmental stages,together with strand-specific RNA-seq,CAGE-seq,and PAS-seq data.Of the 152,026 high-confidence full-length isoforms identified,68.8%have not been described;these include 22,365 isoforms that originate from previously unannotated loci and 82,167 novel isoforms that originate from annotated protein-coding genes.Using our newly developed strategy to detect dynamic expression patterns of isoforms,we identify 13,899 differentially variable regions(DVRs);surprisingly,1275 genes contain more than two DVRs,revealing highly efficient utilization of limited genic regions.We identify 7876 long non-coding RNAs(lncRNAs)from 4098 loci,most of which were preferentially expressed during cell differentiation and meiosis.We also detected 371 long-range interactions involving intergenic lncRNAs(lincRNAs);interestingly,243 were lincRNA-gene ones,and the interacting genes were highly expressed in anthers,suggesting that many potential lncRNA regulators of key genes are required for anther development.This study provides valuable resources and fundamental information for studying the essential transcripts of key genes during anther development.
基金supported by the Natural Science Foundation of Henan Province(242300421028)the National Natural Science Foundation of China(32372091)+3 种基金the Science and Technology Innovation Fund of Henan Agricultural University(202023CXZX002)to ZY.F.the National Key Research and Development Program of China(2021YFF1000304)to Q-W.S.the Natural Science Foundation Youth Fund project of Henan Province(232300421261)to Q-Q.Z.the China Postdoctoral Science Foundation(2024M750812),and Henan Postdoctoral Foundation.
文摘α.-Zeins,the major maize endosperm storage proteins,are transcriptionally regulated by Opaque2(O2)and prolamin-box-binding factor 1(PBF1),with Opaque11(O11)functioning upstream of them.However,whether O11 directly binds toα-zein genes and its regulatory interactions with O2 and PBF1 remain unclear.Using the small-kernel mutant sw1,which exhibits decreased 19-kDa and increased 22-kDaα-zein,we positionally clone O11 and find it directly binds to G-box/E-box motifs.O11 activates 19-kDaα-zein transcription,stronger than PBF1 but weaker than O2.Notably,PBF1 competitively binds to an overlapping E-box/P-box motif,and represses O11-mediated transactivation.Although O11 does not physically interact with O2,it participates in the O2-centered hierarchical network to enhanceα-zein expression.sw1 o2 and sw1 pbf1 double mutants exhibit smaller,more opaque kernels with further reduced 19-kDa and 22-kDaα-zeins compared to the single mutants,suggesting distinct regulatory effects of these transcription factors on 19-kDa and 22-kDaα-zein genes.Promoter motif analysis suggests that O11,PBF1,and O2 directly regulate 19-kDaα-zein genes,while O11 indirectly controls 22-kDaα-zein genes via O2 and PBF1 modulation.These findings identify the unique and coordinated roles of O11,O2,and PBF1 in regulatingα.-zein genes and kernel development.
基金Australian Research Council Linkage project(LP220100292)for partially supporting Mengzhu Wang’s PhD scholarship。
文摘There is increasing interest in developing reduced-crude protein(CP)diets for broiler chickens because their commercial adoption would generate a diverse range of advantages that would enhance the sustainability of the chickenmeat industry.However,the development of reduced-CP broiler diets is proving to be not straightforward,particularly when dietary CP reductions exceed 30 g/kg.The capacity of broilers to accommodate dietary CP reductions when offered maize-based diets is superior to their counterparts offered wheat-based diets.Numerous factors could be contributing to this difference but have yet to be identified with certainty.Maize-based,reduced-CP diets characteristically support better weight gains and efficiencies of feed conversion than wheat-based diets,but this better growth performance is associated with increased fat deposition,monitored as heavier relative abdominal fat-pad weights.This is an intriguing dichotomy.Insulin is a powerful anabolic hormone in mammalian species capable of promoting fat deposition,protein accretion and growth,but the importance of insulin in avian species is usually dismissed.This is because broiler chickens are considered both hyperglycaemic and resistant to insulin.However,the likelihood is that young broiler chickens are more sensitive to insulin than is generally recognised and the anabolic properties of insulin may be contributing to the diverse responses observed between maize and wheat in the context of reduced-CP diets.Dietary CP reductions may trigger increased plasma ammonia concentrations and metabolic acidosis,but both factors can influence insulin secretion and insulin resistance.Maize has slower rates of starch digestion and glucose absorption than wheat and it has been suggested that this generates a more sustained insulin release resulting in increased weight gains and fat deposition.If so,this could be driving the differences generated by the feed grain selected as the basis of reduced-CP diets.The intention of this review is to explore this proposition because if the causal factors of the differences between maize and wheat can be identified the development and acceptance of reduced-CP broiler diets should be accelerated.
基金financially supported by the National Natural Science Foundation of China (32071978)the National Key Research and Development Program of China (2022YFD2300901 and 2022YFD2300905)。
文摘High temperature stress (HT) significantly reduces maize yield by impairing starch accumulation in kernels.However,the mechanism by which HT affects starch synthesis remains controversial-whether through reduced assimilate supply or direct inhibition on kernel metabolism.To clarify these mechanisms,a heat-sensitive maize hybrid,Xianyu 335 (XY),was exposed to 30℃/20℃ (maximum/minimum temperature,control) and 40℃/30℃ for seven consecutive days during the seed setting stage.Synchronous pollination (SP),apical pollination (AP),and shading treatments were applied to manipulate the inherent source–sink ratio in maize plants.Results showed that apical kernel weight decreased by 11.9%under 40℃ in the SP treatment.The ^(13)C content,starch accumulation,and cell-wall invertase (CWIN) activity also declined by 15.9,36.7,and 16.4%,respectively,under HT.In the shading treatment,40℃/30℃ caused even greater reductions in^(13)C content,starch accumulation,and CWIN activity due to diminished assimilate supply.Conversely,in the AP treatment,starch content and CWIN activity increased by 22.0 and 18.5%,respectively,under 40℃/30℃,resulting in kernel weight and ^(13)C content similar to those in SP and shading treatments regardless of temperature.Consistent with apical kernels under AP,HT did not negatively affect middle kernels in either SP or shading treatments,as kernel weight and starch content remained unchanged under HT.Although all kernels were exposed to the same HT or control environment,their responses varied a lot.The impaired starch synthesis in apical kernels under HT was rescued by increasing carbon supply via AP treatment.The contrasting performance among middle kernels,apical kernels under AP,and apical kernels under SP or shading indicates that reduced carbon supply is a critical factor underlying inhibited starch accumulation.Our findings provide a theoretical basis for further understanding kernel abortion under HT.
基金supported by the National Natural Science Foundation of China(32071960)the National Key Research and Development Program of China(2018YFD0300603)。
文摘In maize production,the development of density-tolerant and lodging-resistant varieties has made dense planting an effective strategy for achieving high and stable yields,with superior hybrids serving as a prerequisite for successful highdensity cultivation.However,the photosynthetic mechanisms underlying improved density tolerance in maize hybrids released across different eras in China remain unclear.This study investigates 40 years of breeding progress toward enhanced photosynthetic traits under varying planting densities and elucidates the physiological and ecological bases of improved density tolerance in maize hybrids.A three-year field experiment was conducted from 2019 to 2021 to compare eight major Chinese hybrids from four decadal cohorts under three planting densities:45,000(D1),67,500(D2),and 90,000(D3)plants ha^(-1).At high density(D3),modern hybrids exhibited a more optimal canopy architecture and superior leaf photosynthetic performance compared to older hybrids,despite a slight reduction in specific leaf nitrogen.Notably,modern hybrids(2000s)were able to maintain higher net photosynthetic rates and photosynthetic nitrogen use efficiency(PNUE)at D3,resulting in the highest grain yield(GY),which was 118.47%greater than that of older hybrids(1970s).Leaf area duration after anthesis,total chlorophyll content,key photosynthetic enzyme activities,and maximum quantum efficiency of PSII photochemistry were all positively correlated with GY.Among these,PNUE showed the strongest correlation with grain yield and thus represents a key indicator for optimizing maize hybrids.Based on these findings,breeders should continue selecting hybrids under high-density and suboptimal conditions,focusing on optimizing population architecture and enhancing photosynthetic capacity while fine-tuning leaf nitrogen status to develop high-yielding,density-tolerant hybrids capable of sustaining long-term increases in maize grain yield.
基金supported by the National Natural Science Foundation of China(U2243235)the Shaanxi Provincial Department of Water Resources,China(2022slkj-6)。
文摘The irrigation districts of northern China face issues such as water scarcity,inability to effectively utilize flood resources,and groundwater overexploitation.In view of these challenges,this study proposes a new concept of deep storage irrigation through flood resources utilization.However,whether deep storage irrigation can recharge deep soil moisture and sustain crop production still requires further study.A two-year field experiment was conducted on summer maize in the Guanzhong Plain with five soil wetting layer depths(T1:60 cm;T2:90 cm;T3:120 cm;T4:150 cm;T5:180 cm)and soil saturation moisture content as the irrigation upper limit.The results presented that the ranges of deep soil moisture recharge in the100–200 cm soil profile(SMS_(100–200))was 73.34–267.42 and 0–150.03 mm in 2021(wet season)and 2022(normal season).When the effective precipitation and irrigation exceeded 390 mm,the SMS_(100–200)began to linearly increase.The highest grain yield(GY)were observed at T2 and T3 treatments in 2021(11.44 t ha^(-1))and 2022(11.25 t ha^(-1)),respectively.The maize GY of T4 in 2021 and T5 in 2022 were only 3.9 and 5.7%lower than the maximize GY,respectively.However,the SMS_(100–200)for T4 and T5 were 2.4 and 5.0 times that of T2 and T3 treatments in 2021 and 2022,respectively.Overall,the further increase in irrigation amounts induced only a slight decrease in grain yield,but it significantly increased deep soil moisture recharge.Therefore,the deep storage irrigation breaks through the traditional idea of water-saving irrigation with limited water resources,which can be utilized as an effective alternative to address the issues of water scarcity,low flood resources utilization,and groundwater level declines in the irrigation districts of northern China.
基金supported by grants from the National Natural Science Foundation of China(31771876)the Biological Breeding Program of State Key Laboratory of Sichuan Agricultural University,China(SKL-ZY202234)the Sichuan Province Science and Technology Program,China(2021YFYZ0011 and 2021YFYZ0017)。
文摘Carbohydrate partitioning from source to sink tissues is essential for plant growth and development.However,in maize(Zea mays L.),the molecular mechanisms by which callose synthase genes regulate this process remain largely unexplored.This study demonstrates that mutation of maize callose synthase12(Zm Cals12)results in increased carbohydrate accumulation in photosynthetic leaves but decreased carbohydrate content in sink tissues,leading to plant dwarfing and male sterility.Histochemical β-glucuronidase(GUS)activity assay and m RNA in situ hybridization(ISH)revealed that Zm Cals12 expression mainly occurs in the vascular transport system.Zm Cals12 loss-of-function decreased callose synthase activity and callose deposition in plasmodesmatas(PDs)and surrounding phloem cells(PCs)of the vascular bundle.The drop-and-see(DANS)assay indicated reduced PD permeability in photosynthetic cells and diminished transport competence of leaf veins in Zmcals12 mutants,resulting in decreased symplastic transport.Paraffin section analysis revealed that less-developed vascular cells(VCs)in Zmcals12 mutants likely disrupted sugar transport,contributing to the pleiotropic phenotype.Furthermore,impaired sugar transport inhibited internode development by suppressing auxin(IAA)biosynthesis and signaling in Zmcals12 mutant.These findings elucidate the mechanism by which Zm Cals12-mediated callose deposition and symplastic transport regulate maize growth and development.
基金supported by the Fundamental Research Funds for the Central Universities(N2001020)the National Natural Science Foundation of China(41201359).
文摘Sand dust belts span approximately one-fifth of the global land surface.In these regions,dust tends to settle on vegetation surfaces,altering the observed reflectance and affecting remote sensing detections.To enhance the accuracy of maize growth monitoring in dust-affected regions,this study aims to quantify the effect of sand dust retention on maize during the tasseling stage in the Kashgar Prefecture,Xinjiang Uygur Autonomous Region,China,by analyzing changes in canopy reflectance and vegetation indices.First,field sampling was conducted to measure the key canopy structure parameters and dust retention levels of maize,and laboratory spectral measurements were performed on leaf spectral properties under gradient dust retention.The measured data were then used to drive the LargE-Scale remote sensing data and image Simulation framework(LESS)model for simulating realistic maize canopy spectra across different dust levels,with validation against Sentinel-2 imagery.Second,on the basis of the simulated and satellite-derived spectra,the dust resistance of 36 common vegetation indices was systematically evaluated,and new robust dust-resistant indices were developed.The results showed that compared with dust-free maize,the canopy reflectance of dust-retained maize followed an increase–decrease–increase pattern,with critical turning points at 735 and 1325 nm.The maximum reflectance difference of–0.11755(change rate:29.002%)occurred within the 735–1325 nm range at 24 g/m^(2)dust retention,and the minimum reflectance difference of 0.04285(change rate:148.950%)was observed in the 350–735 nm range under the same dust retention level.Among the 36 vegetation indices,only the global environment monitoring index(GEMI)and the ratio of transformed chlorophyll absorption in reflectance index to optimized soil-adjusted vegetation index(TCARI/OSAVI)exhibited dust resistance,with GEMI being effective below 6 g/m^(2)and TCARI/OSAVI remaining stable across all levels(average ratio:0.970).The newly developed indices in this study,(RE3–RE2)/(NIR–RE2),(RE3–RE2)/(RE4–RE2),and(NIR–RE2)/(RE4–RE2),retained values within the predefined dust-resistant range over the full dust retention levels of 0–24 g/m^(2),thus showing a more stable dust resistance compared with the commonly used 36 vegetation indices.Specially,(RE3–RE2)/(RE4–RE2)performed the most robustly in Sentinel-2 imagery,that is,58.020%of pixels were within the dust-resistant range,and an average ratio of 0.937 was obtained for the original-spectra index.This study provides a scientific basis for crop monitoring and management in dust-affected regions.
基金supported by the earmarked fund for the China Agriculture Research System(CARS-04-PS21)National Key Research and Development Program of China(2024YFD2300401)a recipient of a joint Ph.D.scholarship supported by the China Scholarship Council(CSC)(202306910067)。
文摘The exogenous plant growth regulator,diethyl aminoethyl hexanoate(DA-6),in combination with suitable varieties and planting densities,is important to increase yield in the maize-soybean strip intercropping system.To identify the role of DA-6 in mitigating high-density stress and increasing yield,we conducted a two-year field experiment examining changes in branching architecture and other yield traits of soybeans in maize-soybean strip intercropping systems.In the planting system,two soybean cultivars(ND:Nandou 25 and QH:Qihuang 34)were grown under three planting densities(D1:102,000 plants ha^(-1),D2:130,000 plants ha^(-1),D3:158,000 plants ha^(-1))with DA-6 treatments(DA0:water control;DA60:60 mg L^(-1);DA100:100 mg L^(-1)).Applying DA-6 at 60 mg L^(-1)at the fourth trifoliolate leaf stage increased soybean yield,with QH yield rising by 22.4% and 29.5% at D3 density,and ND yield by 29.5% and 30.0% at D2 density in 2022 and 2023,respectively,compared with D1 under DA0.DA-6improved photosynthesis in both varieties under D2 density,with DA60 increasing ND canopy photosynthetic rate by 15.1%-16.4% and QG by 9.1%-20.6% over two years.In ND,DA-6 enhanced branching,raising the leaf area index by 37%,branch number from 3.6 to 4.7 per plant,and total pod number by 19.7%.In QH,yield grains were mainly due to a 17% increase in the number of stem pods and a 6.5% improvement in hundred-grain weight.In the maize-soybean strip intercropping system,QH achieved a high yield by forming a high-density(D2 to D3)main stem pod,and ND by combining moderate density(D1 to D2)with DA-6-induced branching.
基金Supported by Natural Science Foundation of Guangxi Province(0236005)Educational Commission of Guangxi Province[(2002)316]~~
文摘[Objective] The experiment was aimed to explore character variation between different families after DNA introduction and select variant plants with good stability. [Method] The method of pollen-tube-pathway was used to introduce total DNA of soybean into normal maize inbred line 7313 for selecting generation by generation. When field characters of maize, grain colors, grain traits and panicle axis colors were stable, the crude protein, gliadin, glutelin and oil content of grains which were selected from variant strains were detected and compared. [Result] The grain crude protein, gliadin, glutelin and oil content of line 26h-4-3 were significantly different from these of control treatment. The increments of D3 and D4 generation were 10.34% and 26.70%, 6.58% and 6.28%, 15.09% and 70.34%, 55.82% and 51.52% respectively. All indexes of line 26h-3-1 were also higher than these of control treatment and the increments of D3 and D4 generation were 5.67% and 21.63%,1.91% and 2.31%, 10.85% and 62.27%,22.49% and 9.67%. [Conclusion] The crude protein, gliadin, glutelin and oil content of variant line 26h-4-3 and 26h-3-1 were stable, so variant line 26h-4-3 and 26h-3-1 were excellent variant strains which satisfied the requirement of high protein breeding.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(nyhyzx07004-10)Major Science&Technology Program of Sichuan Province(01NG016-01)~~
文摘The effects of different maize sowing dates and densities on stem and leaf morphological characters and yield of soybean in wheat/maize/soybean relaycropping system were studied. The results showed that with early sowing of maize, the maize yield was promoted, and maize was harvested in advance, which reduced the intergrowth period with soybean and guaranteed soybean＇s proper plant height, larger stem diameter and optimal values of LAI and SLW, so that soybean yield was also increased. The effects of different maize densities on the stem and leaf of soybean mainly were significant before the maize harvest, but soybean yield under high maize density was significantly lower than that under middle and low maize density, and the highest maize yield was under middle density. Based on soybean and maize comprehensive values, the optimum combination of this experiment was sowed on March 21 and planting density was 5.25×10^4 plant/hm^2.
