Wheat is one of the most important food crops globally, providing humans with substantial dietary protein and calories. However, its production is confronted with multiple challenges, such as lodging, wheat stem sawfly infestation, and extreme weather stress, which severely restrict the achievement of high and stable yield. Wheat solid stem not only significantly improves stem strength and enhances lodging resistance, but also forms a physical barrier to resist wheat stem sawfly infection. Meanwhile, it exhibits stronger adaptive advantages under abiotic stresses such as drought and high temperature, making it a crucial trait resource for wheat stress-resistant breeding. This review systematically summarizes the research progress in aspects of the determination period and methods of wheat solid stem trait, the origin, creation and utilization of germplasm resources, the genetic expression characteristics and regulatory networks, the mapping of major QTLs and functional genes, as well as the synergistic relationship between this trait and yield-related traits and the mechanism of stress adaptation. Additionally, the controversies and deficiencies existing in current research are summarized, and the future research directions and application prospects are prospected, aiming to provide theoretical basis for genetic improvement of wheat solid stem trait.

Copper transporters (COPT) are involved in maintaining metal ion homeostasis in plants, but their role in the response of wheat to cadmium (Cd) stress remains unclear. Based on previous transcriptome analysis revealing that TaCOPT3 is significantly upregulated under Cd stress, this study cloned its three homologous copies and systematically analyzed their sequence characteristics, expression patterns, and biological functions. Sequence analysis showed that TaCOPT3-A, TaCOPT3-B, and TaCOPT3-D encode 162, 150, and 162 amino acids, respectively. All contain the conserved Ctr copper transport domain and share 65.40%-68.67% sequence identity with OsCOPT3. Subcellular localization prediction showed that all three copies of TaCOPT3 were localized to the plasma membrane. The promoter regions were rich in hormone-responsive elements (ABA, MeJA, and SA) and MYB transcription factor binding sites. RT-qPCR analysis showed that Cd stress significantly increased the expression of all three TaCOPT3 copies, with levels rising as Cd concentration increased. Under 300 μmol L^-1 CdCl₂ treatment, the expression level of TaCOPT3-A in the shoot was 427 times higher than that of the control, which was higher than that of other copies. Functional analysis showed that under 50 μmol L^-1 and 300 μmol L^-1 CdCl₂ treatment, shoot Cd accumulation in the TaCOPT3-A mutant e0483 was significantly reduced by 44.52% and 30.92%, respectively, compared with the wild type, and the bioconcentration factor (BCF) was significantly reduced by 36.62% and 24.19%, respectively. Haplotype analysis showed that TaCOPT3-A could be divided into two main haplotypes, with haplotype 1 accounting for 63.30% of global wheat germplasm. The known low-Cd-accumulating variety Jimai 22 belongs to this haplotype. Taken together, TaCOPT3 is a Cd-responsive gene in wheat. Loss of function of TaCOPT3-A significantly reduces Cd accumulation in shoots, suggesting its role in regulating Cd transport to the aboveground tissues. These findings provide a theoretical basis for unraveling the mechanism of wheat response to Cd stress.

Drought stress is a major factor restricting maize growth. The drfE gene, encodes a ferritin-like protein from Deinococcus radiodurans and plays an important role in response to abiotic stresses such as drought, oxidation, high salinity, radiation, and extreme temperatures. In this study, a plant expression vector p3301-drfE was constructed and transgenic maize lines overexpressing the drfE gene were obtained and screened for homozygosity. The drought tolerance of the drfE-overexpressing maize was evaluated at both the seedling and adult stages. The seedling stage drought tolerance results showed that under drought stress, the survival rate of drfE-overexpressing lines was significantly higher than that of wild type and the relative water content, POD activity, and CAT activity were significantly increased, while electrical conductivity, MDA content, and H₂O₂ content were significantly reduced. The adult-stage drought tolerance evaluation showed that drfE-overexpressing lines significantly increased ear length, ear weight per spike, 100-kernel weight, and grain yield. DrfE responds to drought stress by regulating peroxidases, drought stress-related kinases, and transcription factors such as WRKY and MYB. In conclusion, the drfE gene can significantly enhance drought tolerance in maize and serves as a promising candidate gene for breeding drought-tolerant maize varieties.

Due to the influence of karst landforms, Guizhou is more susceptible to drought under extreme weather events, posing a serious threat to rapeseed production. Compared to Brassica napus, Brassica juncea exhibits greater drought tolerance in production. Therefore, mining drought-tolerant-related genes and elucidating their molecular functions is of great significance for improving stress resistance and yield in rapeseed. MicroRNAs (miRNAs) have been shown to play critical regulatory roles in plant drought stress response, yet studies in B. juncea remain limited. In this study, two B. juncea lines with contrasting drought responses (G160 and G170) were used. Combined small RNA (sRNA) sequencing and molecular functional assays were performed to predict and functionally analyze drought-responsive miRNAs and their target genes. A total of 44 known and novel drought-responsive miRNAs were identified. RT-qPCR validated the dynamic expression patterns of eight miRNAs under drought stress, revealing that their expression levels were lower in the drought-tolerant line G170 than in the sensitive line G160. Target gene prediction indicated that some target genes are involved in drought response (e.g., ATHBs, PCL5) and ABA signaling pathways (e.g., AHA1, CAR9). Furthermore, heterologous overexpression of BjuMIR9552a in B. napus was performed. Drought-rehydration tests and physiological/biochemical measurements showed that transgenic plants exhibited lower drought tolerance than wild-type plants. RT-qPCR analysis revealed significant downregulation of AHA family genes in the transgenic lines, suggesting that BjuMIR9552a may negatively regulate drought resistance in rapeseed by targeting AHA family genes. This study identified eight miRNAs that may act as repressors of drought stress; overexpression of BjuMIR9552a reduces drought resistance and downregulates AHA family gene expression. These findings provide a new theoretical basis for further dissecting the miRNA-mediated drought response regulatory network in B. juncea.

Enhancing peanut kernel quality is crucial to ensuring grain and oil security and industrial competitiveness, with seed coat color being an important agronomic trait in peanut. In this study, a recombinant inbred line (RIL) population was constructed using Jihuatian 1 (red seed coat) and JM135 (pink seed coat) as parents. Major quality traits of the population kernels were detected using a near-infrared spectrometer. Based on HSV and RGB color space models, the RGB phenotypic data and seed coat color index (p) of the population were obtained. Genetic analysis was performed using the R package SEA v2.0. The results showed that the optimal genetic model for anthocyanin, oil, and sucrose contents in peanut kernels was 4MG-EEEA, for protein and linoleic acid contents, it was 4MG-EEA; and for oleic acid and palmitic acid contents, it was 4MG-CEA. The optimal genetic models for the R, G, B, and p values of peanut seed coat color were all 4MG-EEEA. Furthermore, the gene controlling seed coat color were preliminarily mapped using BSA-seq technology. By employing the ΔSNP-index method and the ED method, the target gene was ultimately located in a 2.06 Mb interval on Arahy.03. Six candidate genes were screened based on gene annotation information. Expression profile and variation analysis indicated that Arahy.07ZIFT? underwent a non-synonymous mutation?, while Arahy.W8TDEC? and ?Arahy.WZ366M? exhibited high expression levels during seed development?, suggesting they are likely candidate genes associated with testa color. The research findings provide a theoretical basis for understanding the genetics and molecular mechanisms of quality traits and seed coat color in peanuts.

Leaf morphology and color in rice influence grain yield by regulating canopy photosynthesis and also contribute to tolerance to both biotic and abiotic stresses. In our previous study, we identified the pale-green leaf and white-hull mutant wp4 (white panicle 4) and fine-mapped it to an approximately 79-kb region on chromosome 8. Here, sequencing of the candidate genes revealed a G-to-A substitution at the exon-intron junction of LOC_Os08g06280/LSD1, resulting in incomplete splicing of the fourth intron. Complementation assays confirmed that LOC_Os08g06280 corresponds to WP4. Introduction of the wild-type genomic sequence of LOC_Os08g06280 into the wp4 restored leaf and hull color as well as photosynthetic pigment content, demonstrating that wp4 is a novel allele of lsd1. WP4 encodes a conserved plant-specific transcription factor containing three zinc-finger domains, and this protein exhibits high conservation with homologous genes across diverse species. RT-qPCR analysis showed that the expression of genes associated with chloroplast development, chlorophyll and carotenoid biosynthesis, and photosynthesis were downregulated in wp4. Together, these results highlight the essential role of WP4 in chloroplast development and chlorophyll synthesis. This work lays a foundation for further investigation of the regulatory mechanisms underlying WP4 function and provides a valuable genetic resource for improving photosynthetic efficiency in rice breeding.

Stigma-exsertion materials can facilitate cross-pollination in mungbean under natural conditions, improve the efficiency of hybrid seed production, and promote the breeding of new mungbean varieties with stigma exsertion. In addition, identifying genes that regulate stigma development will contribute to the utilization of heterosis in mungbean. In this study, the mungbean cultivar Jilyu 7 (WT) was used as the experimental material, and a genetically stable stigma-exsertion mutant, se2, was identified through ethyl methanesulfonate (EMS) mutagenesis and artificial screening. Phenotypic characterization, genetic analysis, and candidate gene mining were subsequently conducted. The results showed that, compared with WT, se2 exhibited a significantly shortened keel flap, an exserted stigma, and normal pollen viability. In field experiments, the pod number per plant, seed number per pod, pod length, and yield per plant of se2 decreased by 83.4%, 60.9%, 25.1%, and 85.4%, respectively, compared with WT. In pot experiments, the number of flowers per plant, pod number per plant, and proportion of shrunken pods in se2 increased by 285.2%, 285.9%, and 67.6%, respectively, whereas the number of mature pods per plant decreased by 93.6%, indicating a significant reduction in seed-setting rate. Segregation ratio statistical analysis of traits in the F₂ population showed that the stigma-exsertion trait was controlled by a single recessive gene. The potential of se2 for mungbean hybrid breeding was further confirmed by bee-assisted pollination. After resequencing the mutant DNA bulk and the wild-type parent, six candidate genes related to stigma exsertion were identified through MutMap analysis, homologous sequence alignment, and expression analysis. This study lays a foundation for elucidating the molecular mechanism underlying stigma-exsertion development and for exploiting heterosis in mungbean.

The rapid development of high-throughput sequencing and phenotyping technologies has generated increasing large-scale genotype and phenotype datasets. The conventional genomic selection (GS) algorithm struggle to handle such data, and computational efficiency has become a key concern in genomic selection. In order to address this problem, this study proposes a novel computationally efficient Haseman-Elston regression+QR decomposition genomic selection (HQGS) method. First, Haseman-Elston regression is used to estimate genetic variance, followed by orthogonal triangular decomposition (QR decomposition) of the core population to obtain an approximate solution for high-dimensional matrices, which greatly improves computational efficiency. In simulated data analysis, different levels of core population size, number of markers, true heritability, and training population size were set to evaluate HQGS, genomic best linear unbiased prediction (GBLUP), random forest (RF), and support vector machine (SVM). In terms of prediction accuracy, HQGS and GBLUP were similar in most cases, both significantly outperforming RF in all cases and outperforming SVM in most cases. In terms of computational efficiency, HQGS significantly outperformed GBLUP, RF, and SVM, with GBLUP being the least efficient. In real data analysis, for 14 traits in wheat population 1, HQGS showed significantly better prediction accuracy than GBLUP for 3 traits, was similar to GBLUP for 8 traits, significantly outperformed RF for 6 traits, was similar to RF for 5 traits, significantly outperformed SVM for 5 traits, and was similar to SVM for 5 traits. For yield data under four environments in wheat population 2, HQGS outperformed GBLUP in three environments, outperformed RF in one environment, was similar to RF in two environments, outperformed SVM in two environments, and was similar to SVM in one environment. This study presents a novel computationally efficient genomic selection method that effectively avoids the inversion of large genetic relationship matrices, significantly improving computational efficiency while maintaining prediction accuracy, providing a more efficient and reliable new approach for handling large datasets.

Peanut (Arachis hypogaea L.) is an important oil crop in China, and breeding varieties with high oil content is a critical approach to enhancing industrial efficiency. Kernel oil content as a typical quantitative trait, is controlled by multiple minor-effect genes. In this study, molecular markers were developed for seven stable oil content quantitative trait loci (QTLs) repeatedly detected across multiple peanut populations. These markers were used to genotype 310 peanut germplasm accessions and the distribution patterns and pyramiding effects of high-oil alleles were systematically analyzed. The results showed that the high-oil allele at a single QTL could increase oil content by 0.38-3.61 percentage points, with phenotypic effects ranging from 53. 79% to 55.47%. The frequency of high-oil alleles varied significantly among different QTLs, with qOCA05 having the lowest frequency (6%) and qOCA06.2 the highest (94%). Only two accessions were found to carry all seven high-oil alleles, with oil contents of 56.36% and 58.59%, indicating that pyramiding multiple genes can significantly increase seed oil content. Analysis revealed that all 60 accessions with oil content above 55% carried at least two high-oil alleles; among them, four accessions with oil content exceeding 60% had pyramided five to six high-oil alleles, suggesting the presence of other genetic factors with larger effects. The findings of this study provide practical molecular markers and important breeding strategies for high-oil peanut breeding.

Castor bean (Ricinus communis L.), an important non-edible oilseed crop worldwide, urgently requires improvement in seed yield to meet the rapidly increasing industrial demand for castor oil. Polyploid breeding is an effective strategy for enhancing plant growth and yield-related traits. Previous studies on the phenotypic effects of whole-genome duplication have mainly focused on allopolyploids, whereas much less is known about variation in growth and yield traits in autopolyploid plants. Here, we investigated growth, physiological, and seed traits in castor bean using a synthetic autotetraploid generated by chromosome doubling of a diploid line, thereby providing a theoretical basis for polyploid breeding and genetic improvement in castor and other oilseed crops. To this end, the diploid castor variety ZB306 and its synthetic autotetraploid counterpart were used as experimental materials, and their ploidy levels were verified by flow cytometry and somatic chromosome counting. Morphological, anatomical, photosynthetic, and seed traits were then compared between tetraploid and diploid plants. The results showed that the genome size and chromosome number of tetraploid castor (2n = 4X = 40) were twice those of diploid castor, confirming that the tetraploid plants were true autotetraploids. Compared with diploid plants, tetraploids exhibited significantly greater plant height, basal stem diameter, leaf area, and leaf thickness. Stomatal length and width were also significantly greater in tetraploid leaves, whereas stomatal density showed a decreasing trend. Anatomical observations further revealed that both cell size and cell number in the lower epidermis, xylem, and parenchymatous tissues, as well as cell size in the palisade tissue, were significantly greater in tetraploid leaves than in diploid leaves. In addition, chlorophyll content, net photosynthetic rate, and transpiration rate were significantly higher in tetraploids than in diploids. Seed-related traits, including seed length, width, thickness, hundred-seed weight, and endosperm oil content, were also significantly greater in tetraploids than in diploids. Overall, autotetraploid castor plants exhibited enhanced vegetative growth and superior yield-related traits compared with their diploid counterparts. These findings not only provide a theoretical basis for polyploid breeding and genetic improvement in castor and other oilseed crops, but also lay the foundation for further studies on the molecular mechanisms underlying trait variation following polyploidization.

Rice yield is a complex quantitative trait controlled by multiple quantitative trait loci (QTL). Dissecting these QTL into single-segment substitution lines (SSSLs) not only improves the accuracy of QTL mapping but also facilitates genome-wide design breeding under a uniform genetic background. In this study, a chromosome segment substitution line, CSSL-Z815, carrying six substituted segments from the indica restorer line R225 in the genetic background of the japonica cultivar Nipponbare, was used. An F₂ population derived from a cross between Nipponbare and Z815 was employed to identify 24 QTL associated with rice yield-related traits. These QTL were distributed on chromosomes 1, 4, 7, and 8 and explained 2.60% to 26.42% of the phenotypic variation. Among them, qGL8 showed the largest additive effect on the long-grain trait in Z815, with a contribution rate of 9.15%. Through marker-assisted selection (MAS), these QTL were further dissected into three single-segment substitution lines (S1-S3). Eleven QTL were consistently expressed and stably inherited in their corresponding SSSLs. In addition, 21 novel yield-related QTL were identified in these SSSLs, including qPH4, qGL7, qRLW7, and qYD8. Furthermore, qGL8 was fine-mapped to a 600 kb interval between markers RM23519 and RM3480 on chromosome 8. Based on resequencing analysis, four candidate genes were identified: LOC_Os08g42980, encoding an LA domain-containing protein; LOC_Os08g43000, encoding a CC-NBS-LRR protein; LOC_Os08g43140, encoding an expressed protein; and LOC_Os08g43160, encoding a TCP family transcription factor. These findings provide important insights for further elucidating the molecular mechanism by which qGL8 regulates grain length.

Plant height (PH) and peduncle length (PL) are critical traits affecting the yield potential and stress adaptation of dryland wheat and dissecting their genetic basis is of great significance for wheat breeding for drought resistance and high yield. In this study, a natural population consisting of 215 wheat accessions was used. Phenotypic evaluations of PH and PL were conducted under multiple drought environments, and genome-wide association analysis was performed using a mixed linear model based on 100K SNP chip genotyping data. The results showed that PH and PL exhibited extensive continuous variation across different environments, with coefficients of variation ranging from 17.74% to 20.90% for PH and from 18.82% to 23.78% for PL. Genotype-by-environment interaction effects were significant, and the broad-sense heritabilities were 0.61 (PH) and 0.67 (PL), respectively. Population structure analysis divided the materials into seven subpopulations with significant differences in PH and PL among subpopulations. A total of 145 significant marker-trait associations were detected, of which 116 were associated with PH and 29 with PL. A stable co-localized hotspot region was identified on chromosome 4D (16.15-19.70 Mb) containing six significant SNP markers repeatedly detected across multiple environments. Based on these markers, the natural population was divided into two haplotypes (HapI and HapII). Compared with HapI, the HapII type showed significantly reduced PH and PL but increased thousand-kernel weight. Three KASP markers were successfully developed from this region and were further validated to be significantly associated with PH and PL in an independent panel of 373 accessions. Combined with transcriptome data and functional annotation, 83 high-confidence genes were identified, within the candidate interval, of which 27 were highly expressed in stems, including known dwarfing genes and several homologous genes not yet functionally characterized in wheat. This study provides important molecular markers and candidate gene resources for plant architecture improvement in dryland wheat.

Drought is one of the major factors restricting agricultural production, especially grain crop production in China. In this study, a field-controlled water experiment was conducted to evaluate the drought resistance of 94 spring wheat varieties (lines) and to analyze their possible known drought-resistance functional genes, providing a reference for the selection of new drought-resistant varieties and the effective utilization of drought-resistant resources. Under drought stress treatment, the measured values of eight field traits—yield, plant height, length of the peduncle, spike length, spikelet number, grains number per spike, thousand-kernel weight and growth period, as well as starch dry basis values related to grain quality traits, were significantly lower than those under normal irrigation treatment. In contrast, the measured values of grain protein content, sedimentation value and wet gluten content increased significantly under drought stress compared to normal irrigation. Correlation analysis of drought resistance indices showed that among the 13 traits, plant height showed a significant positive correlation with the yield-based drought resistance index with good stability, making it a rapid assessment indicator for adult-stage drought resistance in wheat breeding. Using functional markers of drought-resistance-related genes TaDTG6-B, TaPYL1-1B, TaKCS3, TaWD40, TaPP2C6, and TaBADH, genotyping of the 94 materials was performed. The results showed that 12 materials carried the elite haplotype of TaDTG6, 10 materials carried the elite haplotype of TaPP2C6, and no material with haplotype variation of TaWD40 was detected. The elite haplotype of the wax synthesis-related gene TaKCS3 was subjected to directional selection in breeding, with a detection frequency of 67%. Based on the yield-based drought resistance index, 23 high drought-resistant spring wheat varieties (lines) were selected, among which 8 showed strong drought resistance, providing materials and a theoretical basis for wheat drought resistance breeding.

This study aimed to investigate the effects of substituting different proportions of chemical fertilizer with organic fertilizer on sweet corn yield and soil N₂O emission characteristics, so as to provide a theoretical basis for establishing a nitrogen application regime that achieves both high crop yield and environmental friendliness in the oasis irrigation area of Northwest China. A two-year field positioning experiment was conducted at the Wuwei Oasis Agricultural Experimental Station. A conventional chemical fertilizer treatment (CK) was used as the control, and four organic fertilizer substitution treatments were set: replacing 10%, 20%, 30%, and 40% of chemical fertilizer with organic fertilizer (M1, M2, M3, and M4, respectively). By dynamically monitoring soil N₂O flux, soil ammonium nitrogen (NH4⁺-N) and nitrate nitrogen (NO₃^--N) contents, and the activities of nitrate reductase (NR) and nitrite reductase (NiR). we analyzed the effects of partial substitution of chemical fertilizer with organic fertilizer on soil N₂O emissions in sweet corn fields and the underlying mechanisms. Based on the mean results of the two-year experiment, compared with the CK treatment, the M2 treatment significantly increased sweet corn biomass yield and fresh ear yield by 12.57% and 4.51%, respectively, while the M3 and M4 treatments significantly reduced yields. All partial organic fertilizer substitution treatments significantly reduced the peak N₂O emissions after basal fertilization and the first topdressing, as well as the cumulative N₂O emissions during the sweet corn growing season. Compared with CK, the M1, M2, M3, and M4 treatments reduced the global warming potential (GWP) of N₂O by 2.52%-8.89% and the emission intensity (EI) by 3.26%-10.35%. Among them, the M3 treatment exhibited the lowest GWP, and the M2 treatment had the lowest EI. Mantel test and random forest model analysis revealed that cumulative soil N₂O emissions were extremely significantly positively correlated with NH₄⁺-N and NO₃^--N contents, as well as NR and NiR activities at the sowing stage, and significantly positively correlated with NO₃^--N content and NiR activity at the jointing stage. Further analysis using a structural equation model indicated that partial substitution of chemical fertilizer with organic fertilizer primarily reduced N₂O emissions by decreasing the NH₄⁺-N content at the sowing stage, thereby indirectly affecting NO₃^--N content and NiR activity. In conclusion, substituting 20% of chemical fertilizer with organic fertilizer (M2) ensures increased sweet corn yield while significantly reducing soil N₂O emissions, and can be recommended as the optimal fertilization regime for balancing production efficiency and emission reduction goals in the oasis irrigation area.

To address the issues of insufficient organic material input, heavy reliance on chemical nitrogen fertilizers, and low nitrogen use efficiency in spring wheat production in the northwest oasis irrigation region, a field experiment was conducted using different residue returning modes combined with N nitrogen application levels to investigate the regulatory effects of combined green manure and wheat straw return on spring wheat nitrogen application and soil nitrogen status under different N rates, aiming to provide theoretical support and practical basis for nitrogen-saving and efficiency enhancement in spring wheat production. The study was conducted as a field split-plot experiment in the Hexi Oasis Irrigation Area of Gansu province during 2023 to 2024. The main plots comprised three residue return methods: green manure combined with wheat straw return (GS), green manure return alone (G), and fallow after wheat harvest (F). Subplots included four nitrogen application levels: conventional nitrogen (N1, 225 kg hm^-2), 15% nitrogen reduction (N2, 190 kg hm^-2), 30% nitrogen reduction (N3, 155 kg hm^-2), and 45% nitrogen reduction (N4, 120 kg hm^-2). Indicators such as spring wheat nitrogen accumulation and distribution, grain yield, nitrogen use efficiency, and soil nitrogen dynamics were systematically measured and analyzed. The results showed that reduced nitrogen application significantly decreased nitrogen accumulation and grain yield of spring wheat, but the GS treatment effectively compensated for these negative effects. Under the N3 treatment, the nitrogen accumulation of spring wheat in GS from flowering to maturity was on average 18.1% higher than that in the F treatment. Meanwhile, grain yield under GS-N3 was on average 7.5% higher than under F-N1, demonstrating a stable yield maintenance capacity. The GS treatment optimized nitrogen distribution in spring wheat, significantly increasing nitrogen accumulation in grains at maturity and the nitrogen harvest index. Under the same nitrogen application level, the proportion of grain nitrogen allocation in GS was on average 6.7% and 19.8% higher than that in G and F, respectively, and the nitrogen harvest index was on average 11.8% and 11.7% higher, respectively. Under GS-N3, grain N allocation increased by 12.6% on average compared with F-N1, and the nitrogen harvest index increased by 21.4% on average; the nitrogen use efficiency and partial factor productivity of N fertilizer increased by 8.5% and 56.1% on average, respectively, indicating significant nitrogen-saving and efficiency-enhancing effects. GS significantly increased total nitrogen content in the plough layer soil and enhanced soil nitrogen supply capacity. Before sowing, at flowering, and at maturity stages, the total nitrogen content in the 0-20 cm soil layer under GS was on average 23.3%, 16.7%, and 25.7%, higher, respectively, than that under F. GS also significantly increased soil inorganic nitrogen content in the 0-40 cm layer. At different growth stages, compared with F-N1, GS-N3 increased soil nitrate nitrogen content by 4.1%-9.1%, and soil ammonium nitrogen content increased by 4.1%-5.9%, while, no significant increase in inorganic nitrogen content was observed in the 40-80 cm layer. In the Hexi Oasis Irrigation Area, combined green manure and wheat straw return with 30% nitrogen reduction can improve soil nitrogen supply, promote nitrogen absorption by spring wheat, optimize nitrogen allocation to grains, and ultimately ensure stable spring wheat yield while achieving nitrogen saving and efficiency improvement. This practice can be recommended as a green and efficient production technique for spring wheat in the northwest Oasis Irrigation region.

To investigate the effects of high-temperature stress at different developmental stages on grain yield and the physicochemical properties of starch in maize, a field experiment was conducted from 2024 to 2025 using two maize cultivars, Anke 985 (AK985) and Helian 1589 (HL1589). Four high-temperature stress treatments were imposed: stress at the V12 stage (V12-HT), flowering stage (VT-HT), grain formation stage (R2-HT), and grain-filling stage (R3-HT). Changes in starch granule size distribution, pasting properties, thermal characteristics, and yield-related traits of maize grain under high-temperature stress at different stages were analyzed. Compared with the control, high-temperature stress at all stages significantly decreased the volume and surface area proportions of large starch granules (> 18 μm) and increased those of medium-sized (3-18 μm) and small (< 3 μm) starch granules, while having no significant effect on the numerical proportion of starch granules. High-temperature stress at different stages also significantly increased starch pasting parameters, including peak viscosity, trough viscosity, and final viscosity. In contrast, high-temperature stress reduced starch enthalpy, but significantly increased the onset, peak, and conclusion temperatures. In addition, high-temperature stress at all stages significantly reduced grain number per ear and 100-grain weight, ultimately leading to decreased grain yield. Among the treatments, V12-HT and VT-HT caused greater reductions in grain number per ear and yield, whereas R2-HT and R3-HT exerted a more pronounced inhibitory effect on 100-grain weight. Grain starch and fat contents were significantly reduced under all high-temperature treatments, whereas protein content increased. Overall, high-temperature stress at different developmental stages significantly altered starch physicochemical properties by decreasing the volume and surface area proportions of large starch granules, increasing those of medium and small granules, enhancing starch pasting properties, and reducing enthalpy. V12-HT and VT-HT reduced grain yield mainly by decreasing grain number and secondarily by impairing grain filling and reducing grain weight, whereas R2-HT and R3-HT reduced grain yield mainly by inhibiting grain filling and thereby decreasing grain weight. High-temperature stress also reduced grain starch and fat contents while relatively increasing protein content. High-temperature stress decreased the volume and surface area proportions of large starch granules in maize grains, increased those of medium and small starch granules, elevated pasting parameters such as starch setback, and reduced enthalpy.

The winter wheat growth model lacks consideration of the effects of planting density and row spacing on canopy construction, light interception, and yield formation, which limits its application in precision planting management of winter wheat. In this study, a coupled model integrating the Root Zone Water Quality Model (RZWQM) and CERES-Wheat was improved and evaluated using multi-year field experiments with varying planting densities and row spacings. Result indicated that the original model, using a fixed canopy extinction coefficient (K = 0.85), produced significant discrepancies in simulated canopy photosynthetically active radiation interception (PARI) and leaf area index (LAI) compared to observations. The relative root mean square error (RRMSE) for these two variables were 32.98% and 27.56%, respectively, with coefficients of determination (R²) of 0.22 and 0.33. Additionally, simulations for high-density treatments overestimated tiller number (RRMSE = 43.09%; R² = 0.80) and spike number (RRMSE = 35.23%; R² = 0.56), but underestimated kernel number per spike (RRMSE = 35.92%; R² = 0.11), resulting in poor yield response to density and row spacing (RRMSE = 25.00%; R² = 0.18). By incorporating a dynamic extinction coefficient that varies with growth stage and responds to density and row spacing, the new algorithm significantly improved the simulation accuracy for PARI (RRMSE = 16.18%; R² = 0.58) and LAI (RRMSE = 18.62%; R² = 0.73), and enhanced predictions of kernel number (RRMSE = 17.98%; R² = 0.51) and yield (RRMSE = 14.67%; R² = 0.48). Furthermore, introducing a factor for the effect of photosynthetically active radiation on tillering improved simulations of tiller number (RRMSE = 27.11%; R² = 0.79) and spike number (RRMSE = 26.11%; R² = 0.59). The final model, integrating the advantages of the above improvements, greatly enhanced the simulation accuracies for PARI, LAI, tiller number, spike number, grain number per spike, and grain yield improving model adaptability under different planting densities and row spacing conditions and providing important methods for simulating canopy dynamics and yield components in winter wheat.

Soil salinization is a major abiotic stress limiting maize production, and the germination stage is particularly sensitive to salt stress. Enhancing salt tolerance at this stage is therefore crucial for ensuring seedling establishment in saline soils. To investigate the regulatory effects of coronatine (COR) on salt tolerance during maize seed germination, eight widely cultivated maize varieties from the Huang-Huai-Hai region were subjected to germination tests under different NaCl concentrations. Salt tolerance at the germination stage was comprehensively evaluated using subordinate function analysis and cluster analysis, and representative varieties with contrasting salt tolerance were selected. Subsequently, seeds were primed with different concentrations of COR (0, 0.0001, 0.001, 0.01, 0.1 and 1.0 μmol L^-1) to examine its effects on germination performance and key physiological traits under 150 mmol L^-1 NaCl stress. The results showed that salt stress significantly inhibited maize seed germination, with pronounced genotypic differences among varieties. Low concentrations of COR (≤ 0.01 μmol L^-1) effectively alleviated the salt-induced inhibition of seed germination, with 0.01 μmol L^-1 being the optimal concentration, particularly in salt-sensitive varieties. Appropriate COR priming significantly improved germination potential, germination rate, and germination index under salt stress, enhanced α-amylase activity, promoted the accumulation of soluble sugars and soluble proteins, and reduced malondialdehyde content. However, higher COR concentrations (≥ 0.1 μmol L^-1) inhibited seed germination. In conclusion, appropriate coronatine priming enhances salt tolerance during maize seed germination by coordinately regulating germination metabolism, osmotic adjustment, and membrane lipid peroxidation.

Rice-upland rotation is a key agronomic practice for the improvement and sustainable use of saline-alkaline land; however, differences in the ameliorative effects of different preceding crops and their regulatory mechanisms on the root growth of subsequent crops remain unclear. To clarify the cascading relationships among preceding crops, soil quality, and the root systems of subsequent crops, and to provide a theoretical basis for optimizing rice-upland rotation systems in saline-alkaline soils, this study focused on saline-alkaline soil in the Yinbei Irrigation District of Ningxia that had been continuously planted with rice for five years. Four rotation treatments were established: rice-maize (CK), rice-Hunan millet (F1), rice-sweet sorghum (F2), and rice-soybean (F3). After dryland crops harvest, winter triticale was planted in all treatments. Soil physicochemical properties and root morphological traits of the subsequent winter triticale crop were measured, and a soil quality index (SQI) was used for comprehensive evaluation. The results showed that different preceding crops exerted distinct short-term ameliorative effects on the soil, with clear stratification across soil layers. F2 markedly alleviated salinity-alkalinity stress in the surface soil, reducing total salt content by 16.7% compared with CK, but induced salt accumulation in the deeper soil layer. F1 effectively improved deep-soil water retention, whereas F3 significantly enhanced surface-soil fertility, increasing organic matter content by 38.7% compared with CK. A minimum dataset consisting of total salt content, Ca²⁺, K⁺, and pH effectively characterized soil quality, explaining 66.3% of the variation in the total dataset. Based on this dataset, SQI was highest under F2 in the topsoil, whereas CK performed best in the subsoil. The positive effect of soil quality on root morphology of the subsequent winter triticale crop was mainly concentrated from the regreening stage to the jointing stage, while F3 showed a significant delayed advantage at the booting stage. In summary, maize and soybean can be prioritized as preceding crops with complementary functions in rice-upland rotation systems in the Yinbei region: maize is beneficial for maintaining deep-soil quality and promoting early root development, whereas soybean can rapidly improve topsoil fertility and support later growth. This study revealed the sequential patterns by which preceding crops regulate root growth in subsequent crops, thereby providing a theoretical basis for stage-specific root management in crop rotation systems on saline-alkaline soils.

To clarify the synergistic effects of nitrogen application and planting density on the yield and quality of Tartary buckwheat, Chuanqiao 1 was used as the experimental material in this study. A two-factor split-plot design was adopted, with four nitrogen application rates in the main plots: 0 (N0), 60 (N1), 120 (N2), and 180 (N3) kg hm^-2, and three planting densities in the subplots: 750,000 (M1), 1,500,000 (M2), and 2,250,000 (M3) plants hm^-2. The effects of the interaction between nitrogen application and planting density on the canopy light environment, agronomic traits, photosynthetic characteristics, carbon and nitrogen metabolism, yield and its components, and grain nutritional quality of Tartary buckwheat were analyzed. The results showed that nitrogen application, planting density, and their interaction had significant or highly significant effects on light intensity, light quality distribution, agronomic traits, photosynthetic parameters, key enzymes involved in carbon and nitrogen metabolism, and yield and quality traits in the middle and lower canopy. The appropriate combination of nitrogen application and planting density (M2N1) improved the canopy light environment by optimizing population structure, thereby affecting photosynthesis as well as population yield and quality. Under the M2N1 treatment, the highest yields in spring and autumn were 2258 kg hm^-2 and 2180 kg hm^-2, respectively. At the same time, M2N1 significantly increased the contents of crude fat, crude protein, flavonoids, polyphenols, and total starch in the grains, with the mean values across the two seasons being 66.48%, 20.49%, 71.82%, 78.57%, and 21.67% higher, respectively, than those under M3N3. Correlation analysis showed that blue light intensity within the canopy was significantly and positively correlated with the contents of total flavonoids, rutin, and quercetin in the grains, with correlation coefficients of 0.381, 0.586, and 0.561, respectively, whereas no significant correlation was found between red light and any quality trait. Therefore, the optimal combination for the synergistic improvement of yield and quality in Tartary buckwheat was a nitrogen application rate of 60 kg hm^-2 and a planting density of 1,500,000 plants hm^-2.

Drip fertigation provides an effective approach for precise nitrogen regulation in summer maize. However, the mechanisms by which nitrogen fertilizer type and management strategy can be synergistically optimized to better match crop nitrogen demand while improving nitrogen use efficiency remain poorly understood. In this study, two nitrogen forms, urea (U) and urea ammonium nitrate solution (UAN), and four split-application strategies with different pre- and post-silking topdressing ratios were established: 40%+60% (T1), 50%+50% (T2), 60%+40% (T3), and 50%+50% with four equal split applications (T4). Treatments T1-T3 involved variable-rate topdressing, with applications before silking at V6:V12 = 1:2 and after silking at R1:R2 = 2:1, whereas T4 involved four uniform topdressings. In addition, a no-nitrogen control (Tn) and a traditional rainfed single-application fertilization treatment (Tt) were included. This study systematically investigated the effects of nitrogen form and application strategy on yield formation and nitrogen use efficiency in summer maize. The results showed that, compared with urea, UAN improved ear traits, increased grain yield by 11.9%-24.9%, and enhanced agronomic nitrogen efficiency by 26.4%-74.2%. Among the different nitrogen management strategies, T3 (60% pre-silking+40% post-silking) performed best. By promoting dry matter and nitrogen accumulation at silking and optimizing dry matter and nitrogen translocation after silking, T3 achieved the highest grain yield and nitrogen partial factor productivity. These results indicate that combining the diverse nitrogen forms supplied by UAN with the precise timing of the T3 strategy can optimize the source-sink relationship in summer maize and synergistically improve both grain yield and nitrogen use efficiency. Therefore, in the summer maize region of the Huang-Huai-Hai Plain, the application of UAN combined with a pre-silking-heavy nitrogen strategy under drip fertigation represents an effective approach for simultaneously achieving high yield in densely planted maize and high nitrogen use efficiency.

Potato starch is widely used in various industrial fields. However, due to significant differences in phenotype, genetic background, and processing quality among different high-starch potato varieties, their comprehensive utilization potential urgently requires further in-depth investigation. In this study, 41 high-starch potato varieties were used as experimental materials to systematically analyze phenotypic traits, SSR based molecular genetic diversity, and starch physicochemical properties. The results showed that the coefficients of variation for nine phenotypic and quality traits ranged from 7.09% to 47.22%, and the genetic diversity index ranged from 1.14 to 2.07, indicating relatively abundant genetic variation. Using SSR primers associated with starch content, a total of 73 bands were detected with a polymorphism rate of 94.52%. At a genetic similarity coefficient of 0.65, the materials were classified into four groups, among which 36 potato varieties were clustered in Group II and the remaining five varieties were clustered in Groups I, III, and IV. Significant differences were observed among varieties in six traits, including amylose content, transparency, and freeze-thaw stability. Cluster analysis based on these traits divided the varieties into two groups, reflecting clear differentiation in processing applications. Association analysis between SSR markers and 15 traits identified 5 SSR markers associated with 8 traits. These findings provide an important theoretical foundation for the breeding of starch-processing potato varieties and the rational utilization of germplasm resources.

The purpose of this study was to investigate the effects of plant growth regulators (PGRs) on the growth of aboveground and underground parts, photosynthesis, stress physiology, and storage roots in sweet potato. Controlled field experiments were conducted using Yuhongxinshu 98 as the experimental material. Seven treatments were applied: normal soil moisture (CK), early-stage drought stress (D), early-stage drought stress+6-BA (D1), late-stage waterlogging stress (W), late-stage waterlogging stress + uniconazole (W1), DW, and D1W1. We investigated the effects of these two stresses and analyzed the roles of PGRs in yield and quality, the growth of the main vine and underground parts, photosynthetic characteristics, osmotic adjustment substances, and the activities of stress-related enzymes. The results showed that: (1) the three types of water stress, namely D, W, and DW, caused substantial reductions in sweet potato yield, by 55.65%, 35.62%, and 54.20%, respectively. After exogenous application of PGRs, the yields of D1, W1, and D1W1 increased by 45.14%, 48.84%, and 58.10%, respectively, compared with those of D, W, and DW. (2) Water stress under D, W, and DW significantly decreased the contents of starch, soluble protein, and soluble sugar in the storage roots of sweet potato, and spraying 6-BA and uniconazole effectively improved these quality traits. (3) D1 and W1 were beneficial to main vine thickening in sweet potato. W1 significantly inhibited the elongation of the main vine, and its ratio of root-to-shoot (R/T) was significantly higher than that of W. (4) The net photosynthetic rate (P_n) was inhibited by treatment D, which resulted in a hysteresis effect. Compared with CK, stomatal conductance (G_s) under D and W decreased by 21.92% and 19.05%, respectively. (5) Both D and D1 increased proline (Pro) and soluble protein contents in the leaves. (6) Both drought stress and waterlogging stress significantly enhanced catalase (CAT) activity. After spraying 6-BA and uniconazole, namely under D1 and W1, CAT activity remained higher than that in CK. In conclusion, whether as single drought stress, single waterlogging stress, or drought followed by waterlogging stress, all three stress conditions affected the normal growth and yield formation of sweet potato. After exposure to these stresses, spraying 6-BA under drought stress or uniconazole under waterlogging stress alleviated the negative effects, improved storage root quality and photosynthetic capacity, regulated the contents of osmotic adjustment substances, promoted the activities of stress-related enzymes, enhanced the adaptability of sweet potato to these two stresses, and reduced stress injury, ultimately increasing the yield and quality of storage roots under water stress.