The super rice variety Nanjing 5718 has been designated as a leading variety by the Ministry of Agriculture and Rural Affairs and has demonstrated outstanding lodging resistance in large-scale production.Studying the stem characteristics of Nanjing 5718 and elucidating the molecular mechanisms underlying its lodging resistance can provide new insights for breeding lodging-resistant rice varieties.The lodging-resistant super rice Nanjing 5718 and two varieties,Nanjing 518 and Nanjing 58,with weak lodging resistance,were used as materials to compare agronomic traits,stem characteristics and their correlation with lodging resistance.The plant height and center of gravity of Nanjing 5718 were significantly lower than those of other varieties at 20 days after heading.The length of the second basal internode,stem diameter and stem wall thickness of the second and third basal internodes of Nanjing 5718 were significantly higher than other varieties at 20 days after heading.High content of cellulase and lignin in the stem was the important factor leading to strong lodging resistance.No significant differences in cellulase activity were observed in the second basal internodes among the three varieties.Compared to the other two varieties,only the pPLAⅢα,bHLH002,ILA1 and NAC5 among the 102 genes related to the cellulose and lignin biosynthetic pathways had missense mutations in their coding regions in Nanjing 5718.The relative expression levels of key cellulose biosynthesis-regulating genes,such as MYB61, SLR1,PIL13, PG3, ERF34,DPH1 and MYB7 were significantly different between Nanjing 5718 and Nanjing 58.Significant differences were also observed in the relative expression levels of some lignin metabolism genes between Nanjing 5718 and Nanjing 58:4CL3,RLM1,CYP98A4,SWN1,PAL1,and so on.The differential expression of those genes in basal internodes likely underlies the high cellulose and lignin content of stem and consequent strong lodging resistance in Nanjing 5718.In conclusion,the strong lodging resistance of the super rice variety Nanjing 5718 results from its increased internode diameter and stem wall thickness.The higher contents of cellulose and lignin in the internodes provide a structural basis for this enhanced lodging resistance.Variations in the expression of key genes involved in the cellulose and lignin biosynthesis pathways may be the primary factor contributing to the superior lodging resistance observed in Nanjing 5718.

This study aimed to elucidate the compositional differences and molecular regulatory mechanisms of anthocyanins in kernels of fresh-eating maize with different colors by integrating metabolomic and transcriptomic analyses,thereby providing candidate genes and a theoretical basis for molecular breeding of colored fresh-eating maize.White WN2000,yellow HN,colored CN1,and black HTN188 were used as materials.Metabolomics was employed to identify anthocyanin-related metabolites and screen differential metabolites;transcriptome sequencing was conducted to obtain differentially expressed genes(DEGs).Metabolite gene associations were analyzed through GO annotation and KEGG pathway enrichment,and key structural genes and transcriptional regulators were mined within the anthocyanin biosynthetic pathway.The results showed that 49 anthocyanin-related metabolites were identified in total.Major anthocyanins,including cyanidin,peonidin,and pelargonidin,accumulated significantly in HTN188,indicating stronger pigment deposition.Transcriptome analysis identified 12 557 DEGs,among which structural genes such as F3H,DFR,and UFGT,as well as transcription factors including MYB and bHLH,were significantly up-regulated in varieties with high anthocyanin content.Correlation analysis revealed that the expression level of Zm00001d011438 was significantly and positively correlated with total anthocyanin content,suggesting that it may play a key role in kernel anthocyanin accumulation.Overall,the integrated metabolomic and transcriptomic analyses characterized differences in anthocyanin composition and related gene expression among differently colored fresh-eating maize kernels,and identified structural genes,transcription factors,and the candidate Zm00001d011438 associated with the anthocyanin biosynthetic pathway,providing references for subsequent functional validation and genetic improvement.

The identification of the wheat lamina joint regulator LIGULELESS 2 (LG2) and analysis of its interacting proteins are of great significance for exploring the molecular mechanisms underlying lamina joint formation and leaf angle regulation, as well as for breeding new varieties with ideal plant architecture. First, two homologous genes of LG2, designated TaLG2 and TaLG2L, were identified in the wheat genome through phylogenetic analysis, each containing three homoeologous copies located in the A, B, and D subgenomes with more than 90% sequence similarity. Transcriptome-based expression profiling during lamina joint development and in different leaf tissues revealed that both TaLG2 and TaLG2L were specifically expressed in the lamina joint. Except for TaLG2-3A, the other five homoeologs exhibited specific expression at the early S1 stage of lamina joint development. The bait vector pGBKT7-TaLG2L-1A was constructed and used for yeast two-hybrid (Y2H) screening yielding 174 positive clones.Sequencing analysis identified 68 candidate interacting proteins of TaLG2L-1A. GO enrichment analysis showed that these proteins were mainly involved in ubiquitin binding, cation binding, and mRNA binding. Further rotation verification and pairwise Y2H assays demonstrated that TaLG2L-1A can interact with the auxin response factor TaARF17 and the blue light receptor cryptochrome TaCRY1, respectively. This study clarifies the tissue-specific expression patterns of wheat LG2 homologs, identifies and obtains key interacting proteins TaARF17 and TaCRY1 of TaLG2L-1A, and reveals the molecular mechanism by which LG2 may coordinate auxin and light signaling pathways to regulate lamina joint formation and leaf angle development.

This study aimed to clarify the regulatory mechanism of exogenous glycine betaine(GB)on the antioxidant and photosynthetic systems of maize seedling leaves under combined heat and drought stress(TD),providing a theoretical basis for alleviating crop stress under extreme environments.Using the maize variety Xianyu 335 as experimental material,different concentrations of GB(0,50,100,200,and 400 mmol/L)were applied to the leaves at the three-leaf-one-heart stage.After 24 hours,combined stress was simulated in a climate chamber with high temperature(day/night temperature of 40 ℃/28 ℃)and 20% PEG-6000 to induce moderate drought,exploring the regulatory effects of GB on the antioxidant system and photosynthesis of maize seedlings.The results showed that 100 mmol/L GB significantly promoted plant growth.Compared with the TD treatment,plant height,leaf area,shoot dry weight,and root dry weight increased by 27.48%,27.45%,28.33%,and 78.26%,respectively,while the root-to-shoot ratio increased by 14.91 percentage points.On the 5th day after stress,100 mmol/L GB significantly enhanced antioxidant enzyme activities,with superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT)activities increasing by 69.09%,69.02%,and 41.81%,respectively.Simultaneously,the contents of malondialdehyde(MDA),superoxide anion($\mathrm{O}^{\bar{.}}_{2}$),and hydrogen peroxide(H₂O₂)decreased by 21.92%,6.50%,and 25.33%,respectively.Furthermore,soluble sugar(SS)and soluble protein(SP)contents increased by 31.69% and 18.98%.Photosynthetic characterization analysis indicated that GB effectively improved the lamellar system structure of chloroplast grana and stroma thylakoids,thereby significantly increasing the SPAD value under combined stress and alleviating damage to the photosystem Ⅱ(PSⅡ)reaction center.This was manifested by a decrease in minimal fluorescence(F0)and increases in variable fluorescence(Fv)and maximum fluorescence(Fm).Additionally,by mitigating the stomatal and non-stomatal limitations caused by combined stress,GB treatment significantly enhanced photosynthetic performance,increasing the net photosynthetic rate(Pn)by 24.14% on the 5th day after stress.In conclusion,under combined heat and drought stress,exogenous GB can protect the photosynthetic system by enhancing antioxidant enzyme activities and osmotic adjustment capacity,thereby alleviating stress damage and promoting the growth of maize seedlings.

To elucidate the intrinsic mechanisms underlying the amelioration of degraded black soils by organic fertilizers,and thereby provide a scientific basis for optimizing chemical fertilizer reduction strategies while safeguarding long-term soil productivity in the target region,a maize field trial was conducted in 2024.Six fertilization treatments were established,as follows:CF(regular fertilization),RF(20% reduction of chemical fertilizer),RFH1(RF supplemented with 200 kg/ha humic acid fertilizer),RFH2(RF supplemented with 330 kg/ha humic acid fertilizer),RFO1(RF supplemented with 200 kg/ha chicken manure organic fertilizer)and RFO2(RF supplemented with 330 kg/ha chicken manure organic fertilizer).Compared to CF and RF,the RFH2,RFO1,and RFO2 treatments significantly reduced soil bulk density by 12.4%—20.7%.All organic amendment treatments improved soil structure stability,and the fraction of water-stable aggregates(>0.25 mm)increased by 15.9%—39.1%,while soil pH decreased by 0.8%—1.2%.RFO1 and RFO2 elevated soil alkaline hydrolyzable nitrogen content by 14.6%—28.5%.Additionally,every organic treatment increased soil available phosphorus and soil organic matter contents by 8.7%—36.8% and 11.0%—48.9%,respectively,with RFO2 showing the most pronounced improvements.At the same time,RFH2,RFO1,and RFO2 significantly enhanced the activities of key soil enzymes(urease,amylase,catalase,alkaline phosphatase,and sucrase)by 18.1%—72.4%.In terms of grain yield,RFH2,RFO1,and RFO2 outperformed CF by 0.5%—13.9%,and all organic amended treatments increased by 16.7%—36.6% compared with RF,with RFO2 achieving the highest yield.Organic amended treatments also improved partial productivity and agronomic efficiency of fertilizers by 11.9%—31.1%,while RFO2 exhibited 25.8%—36.6% higher nitrogen and phosphorus partial productivity compared to CF and RF.Overall,chemical fertilizer reduction combined with organic fertilizer effectively improved soil physicochemical properties,enhanced soil enzyme activities,and increased nutrient-use efficiency.This practice not only maintained maize yield but also contributed to the restoration of degraded black soils.Thus,20% chemical fertilizer reduction combined with 330 kg/ha chicken manure organic fertilizer(RFO2)was identified as the optimal fertilization strategy for degraded black soils in this experiment.

In order to explore the effects of mulching measures(such as straw returning and plastic film mulching)on soil aggregates and organic carbon in semi-arid rain-fed agricultural areas.The potato-wheat rotation system in the dryland of Longzhong was used as the research object.The effects of straw stubble mulching(SR),straw strip mulching(SM),plastic film mulching(PM)and open field(CK)on soil organic carbon components(SOC,POC,MAOC),aggregate stability and aggregate carbon contribution rate were systematically analyzed.By evaluating the soil improvement effect of different mulching measures,integrating the intrinsic indicators such as soil organic carbon component dynamics,aggregate stability and crop productivity and water use efficiency data reported in the literature,the optimal mulching mode that can synergistically improve organic carbon and aggregate stability was screened.The results showed that the organic carbon content and aggregate stability of potato and wheat were improved by three mulching measures in potato-wheat rotation,and the effect of SR treatment was the best.Compared with CK treatment,the SOC content of SR and SM treatment increased by 15.38% and 7.78%,and the SOC content of PM treatment did not change significantly.SR and SM treatment increased the POC content in 0—20 cm soil layer by 18.54%,16.62%,and PM decreased the POC content in 0—20 cm soil layer by 3.06%.The overall trend of MAOC increased in each treatment was SR>SM>PM>CK.Compared with CK treatment,SR and SM treatments increased the proportion of MWD,GMD,>2 mm aggregates and SOC content,while PM significantly reduced MWD and GMD.SR increased the SOC enrichment coefficient of>2 mm aggregates by 17.26% in 0—20 cm soil layer,and SR and SM treatments significantly increased the SOC contribution rate of>2 mm aggregates.In summary,under the conditions of this experiment,all three mulching measures can increase soil organic carbon content,and straw stubble mulching returning to the field has the best effect in improving soil organic carbon content and aggregate stability,effectively improving soil fertility.

To clarify the effects of different nitrogen forms combined with magnesium fertilization on potato in the northern foothills of Yinshan Mountains,a field experiment was conducted in Hohhot,Inner Mongolia.The experiment included two nitrogen forms(nitrate nitrogen and ammonium nitrogen)and two magnesium application rates(0,45 kg/ha),resulting in four treatments.The impacts of these treatments on potato yield and its components,dry matter,nitrogen,magnesium,and potassium contents,their accumulation,and nitrogen use efficiency throughout the growth period were analyzed.The results showed that,compared with the application of nitrate nitrogen alone,the combined application of nitrate nitrogen and magnesium significantly increased potato leaf dry matter(21.24%—75.60%)and tuber dry matter(22.04%—62.36%)from tuber initiation stage to harvest stage,as well as whole-plant dry matter(32.54%—70.28%)from seedling stage to harvest stage.It also enhanced nitrogen accumulation(44.01%—69.84%)in tuber initiation stage,starch accumulation stage and harvest stage,whole-plant magnesium accumulation(37.66%—84.21%)during the entire growth period,whole-plant potassium accumulation (24.30%—54.95%) from tuber initiation stage to harvest stage, nitrogen uptake efficiency (30.77%—66.67%) during the entire growth period,and partial factor productivity of nitrogen fertilizer at harvest stage(35.13%).Correlation analysis indicated that potato dry matter,whole-plant nitrogen,magnesium,and potassium accumulation were significantly positively correlated with nitrogen uptake efficiency during the entire growth period(r was all greater than 0.78).At harvest stage,whole-plant potassium content showed a highly significant negative correlation with yield(r was -0.78).Principal component analysis further demonstrated that the total variation among treatments during the entire growth period was highly dispersed,indicating significant differences between nitrogen form combined with magnesium fertilization treatments and those without magnesium application.These findings provide a new strategy for improving nitrogen use efficiency and optimizing nitrogen-magnesium management in potato production in the northern foothills of Yinshan Mountains.

In order to explore the gene function of nerve growth factor(NGF),and to clarify the expression differences of NGF in different tissues of Red Steppe cattle and its influence on the myogenic differentiation of bovine skeletal muscle satellite cells(bSMSCs),collect various tissues of the Red Steppe cattle,clone and obtain the complete CDS region of the NGF gene,and then conduct bioinformatics and tissue expression analysis on it.bSMSCs were isolated from the deep tissues of the hind limbs of neonatal calves.The expression of Pax7,Desmin and MyoD1,the specific markers of bSMSCs,was detected by immunofluorescence staining.In vitro,2% horse serum was used to induce myogenic differentiation of bSMSCs by serum deprivation method,and the expression patterns of NGF mRNA and protein at different stages of differentiation were detected.The results showed that the length of the CDS region of bovine NGF gene was 726 bp,encoding 241 amino acids.The amino acid sequence of Red Steppe NGF gene is located in a branch of house mouse,red deer and sheep,with high homology and close kinship.The molecular weight of NGF protein was about 26.67 ku,the molecular formula was C₁₁₇₉H₁₈₆₁N₃₄₉O₃₃₉S₁₀,the theoretical isoelectric point was 9.72,the half-life was 30 h,and the NGF protein was water soluble.NGF protein had signal peptide and was secreted protein.There were 42 potential phosphorylation sites.There were three potential sites for N-glycosylation.The secondary structure of NGF protein was composed of α-helix,β-sheet,β-turn and random coil,and the results of tertiary structure prediction were consistent with those of NGF protein.There were significant differences in the expression level of NGF gene in different tissues,with the highest expression level in liver,followed by kidney and tumour.The expression of the NGF gene was continuously upregulated during the myogenic differentiation process of bSMSCs,and there was a significant difference on the 7th day.This study successfully cloned the CDS region sequence of the NGF gene in the grassland,and established the tissue expression profile of the NGF gene in the Red Steppe cattle.The expression pattern of the NGF gene during the myogenic differentiation process of bSMSCs was clarified.

To clone the full-length cDNA sequence of the MSTN(Myostatin)gene from Gymnocypris przewalskii,clarify its expression characteristics in different tissues of G.przewalskii and expression differences in the muscle tissues of different Cyprinidae fishes,and provide basic data for exploring the molecular mechanism underlying the slow growth of G.przewalskii.5'RACE and 3'RACE techniques were used to clone the full-length cDNA sequence of the MSTN gene from G.przewalskii.Bioinformatics methods were employed to analyze its sequence characteristics,and Quantitative Real-time PCR(RT-qPCR)was used to detect the differential expression of this gene in different tissues of G.przewalskii and muscle tissues of different Cyprinidae fishes.The results showed that the full-length cDNA sequence of the MSTN gene from G.przewalskii was 2 168 bp,including an open reading frame(ORF)of 1 128 bp encoding 375 amino acids,with ATG as the start codon and TGA as the stop codon.The predicted encoded protein contained 70 threonine(Thr)phosphorylation sites.Phylogenetic analysis showed that the MSTN gene of G.przewalskii clustered with homologous genes of other Cyprinidae fishes,indicating a close genetic relationship.RT-qPCR results revealed that MSTN was expressed in gill,kidney,liver,heart,brain,muscle,and skin tissues of G.przewalskii,with relatively high expression levels in the brain and muscle tissues.Among different Cyprinidae fishes,the expression level of the MSTN gene was relatively higher in G.przewalskii and Gymnocypris eckloni,while relatively lower in Ctenopharyngodon idella,Carassius auratus,and Megalobrama amblycephala.The full-length cDNA sequence of the MSTN gene from G.przewalskii was successfully cloned,and its sequence characteristics and evolutionary status were clarified,the expression differences of this gene in different tissues of G.przewalskii and among different Cyprinidae fishes were revealed.

Drought is one of the key factors limiting the yield of japonica rice.Exploring the genetic mechanism of drought tolerance in japonica rice at the germination stage,screening drought-tolerant candidate genes,and identifying their superior haplotypes provide a theoretical basis for deciphering the drought tolerance mechanism of japonica rice at the germination stage and developing related molecular markers.139 core germplasm resources of japonica rice from Northwest China were used as materials.Japonica rice seeds after radicle emergence were subjected to simulated drought stress using 15% PEG-6000.Six drought tolerance-related traits,including relative germination rate(RGR)and relative root length(RRL),were determined.Combined with 255 501 high-quality single nucleotide polymorphisms(SNPs),genome-wide association studies(GWAS)were conducted using the general linear model(GLM),mixed linear model(MLM),and fixed and random model circulating probability unification(FarmCPU)model.Haplotype analysis was further performed based on drought tolerance phenotypic data to identify potential candidate genes.The results showed that the mean values of the six drought tolerance traits followed a normal distribution,with coefficients of variation(CV)ranging from 3.43% to 56.25%.Among these traits,the relative root and shoot dry weight(RRSDW)exhibited the largest CV and showed a significantly positive correlation with relative root length(RRL),relative shoot length(RSL),and relative root and shoot fresh weight(RRSFW).GWAS for the six drought tolerance traits using high-density SNPs detected a total of 1 164 distinct SNPs,among which 379 were regarded as high-confidence SNPs loci and 6 as quantitative trait nucleotides(QTNs).By integrating the 50 kb upstream and downstream regions of these loci,14 significant SNPs loci were screened out,corresponding to 14 reliable quantitative trait loci(QTL)candidate intervals,which were mainly significantly associated with RRSDW.Genes within these 14 intervals were further predicted and analyzed using databases.With missense mutations in exons as the criterion,the gene LOC_Os03g56130,which encodes lichenase-2 precursor,was identified.Combined with drought tolerance phenotypes,haplotype analysis of this gene revealed that 5 missense mutations in exons constituted 4 haplotypes.Among them,Hap.2 showed a significantly higher RRSDW than the other haplotypes,being identified as the superior haplotype.These findings indicate that LOC_Os03g56130 is a potential candidate gene associated with drought tolerance in japonica rice at the germination stage.

In order to further analyze the genetic basis regulating the protein content of super sweet corn stalk,this study used the BLINK model to locate the major SNP loci and predict candidate genes controlling the trait,based on the maize 56K gene chip.The results showed that during the harvest period of super sweet corn,the protein content of stalk ranged from 12.63 to 30.29 g/kg,with an average of 20.76 g/kg,showing a normal distribution.Six significant SNP loci regulating the protein content of super sweet corn stalk were identified by GWAS.These loci were distributed on chromosomes 1,4 and 6,and their contribution rates ranged from 10.07% to 18.17%.Among them,Affx-115330268 on chromosome 6 had the highest contribution rate.A total of 184 candidate genes were detected in the 200 kb confidence interval between the upstream and downstream of the significant association sites,of which 34 were annotated genes,accounting for 18.48%.Through GO functional annotation and KEGG pathway enrichment analysis,candidate genes were mainly involved in biological processes such as biological regulation,cellular processes,and catalytic activity,and were enriched in steroid biosynthesis,tryptophan metabolism,photosynthesis-antenna protein and other pathways.Based on the literature search and comparison,it was found that six key genes (GRMZM2G141473, GRMZM2G007854, GRMZM2G111319, GRMZM2G121024, GRMZM2G010353, GRMZM2G049547) that regulate the protein content of super sweet corn stalk,which are mainly involved in protein and enzyme synthesis.

To determine the optimum strip configuration for the intercropping of soybean and maize with different border-row advantages,the field experiments were carried out in two distinct ecological regions,Jian'an District of Xuchang City and Shangshui County of Zhoukou City,Henan Province.The experimental materials included two maize varieties with strong border-row advantage(MC121 and Denghai 3206(DH3206)),and two with weak border-row advantage(Haoyu 16(HY16)and MY73),previously screened,and one soybean variety Jindou 99(JD99).Two strip intercropping patterns were established∶6 rows of soybeans alternating with 4 rows of maize(6S4M)and 4 rows of soybeans alternating with 2 rows of maize(4S2M).Sole cropping of soybeans(CKS)and maize(CKM)were set as the controls.This study investigated the variations in maize agronomic traits,dry shoot weight,yield and its components of each row under different strip patterns,and compared the differences of land equivalent ratio(LER).The results showed that the LER was greater than 1 in 12 of the 16 treatments formed by two strip configurations for four maize varieties in the two ecological regions,and the LER of maize varieties HY16 and MY73 was greater than 1 under each strip configuration at two sites.The LER of MC121 and DH3206,with strong border-row advantage,was higher in strip type of 4S2M than that of 6S4M.In contrast,the LER of HY16,with weak border-row advantage,was higher in strip type of 6S4M than that of 4S2M,while it was opposite for MY73.Under 6S4M planting pattern,stem diameter,canopy light transmittance,chlorophyll a and chlorophyll b contents in ear leaf and leaf below the ear of maize variety DH3206 decreased with the increase of border row order;bottom light transmittance,chlorophyll b content in ear leaf and leaf below the ear of maize variety MC121 decreased with the increase of border row order in two experimental sites.The yield of maize varieties MC121 and DH3206 with strong border-row advantage in Jian'an District and Shangshui County decreased by 23.71%,27.00% and by 20.03%,9.05%,respectively.The dry shoot weight per plant of the edge row-2 at maturity decreased by 15.87%,19.93% and by 13.82%,24.56%,respectively,compared with the edge row-1.In contrast,there was no significant change in yield and dry shoot weight per plant at maturity between the edge row-1 and the edge row-2 of maize varieties with weak border-row advantage.In conclusion,the average LER of varieties with weak border-row advantage is higher than those with strong border-row advantage under the same strip configuration,and maize yield difference between intercropping and monoculture is seriously affected by variety type.Therefore,screening and matching suitable maize varieties is essential for improving the yield and benefit of soybean-maize strip intercropping system.