【Objective】Soil salinization severely constrains the sustainable development of rice production. The specific goals are to: comprehensively evaluate the salt tolerance of rice core germplasm accessions at the seedling stage, investigate the morphological and physiological characteristics of different rice subspecies under salt stress, clarify the associated variations in their responses, and summarize their adaptive strategies, thereby providing a theoretical foundation for screening and breeding salt-tolerant rice varieties.【Method】The salt tolerance score (STS), plant height, root length, shoot fresh weight, shoot dry weight, root dry weight and SPAD were measured for 276 rice core germplasm accessions after treatment using 125 mmol·L^-1 NaCl for 6 days. The relative values of each trait, except for STS and shoot fresh weight were calculated, along with the shoot water content (SWC). T-tests, significance analysis and correlation analysis were used to explore the morphological and physiological differences for salt stress responses among different rice subspecies. Principal component analysis (PCA) and stepwise linear regression were applied to screen key indicators for salt tolerance. The D-value was calculated to identify typical salt-tolerant accessions and salt-sensitive accessions, which were used to elucidate the regulatory patterns and response strategies of salt stress in different subspecies of rice.【Result】Salt stress affected the growth of seedlings of the three subspecies of rice. Compared with japonica rice, indica rice and AUS exhibited milder inhibitory effects from salt stress, and AUS demonstrated greater phenotypic variation. The STS, relative seedling height (RSH), relative root length (RRL), relative root dry weight (RRDW), relative SPAD (RSPAD) and SWC among the three subspecies of rice accessions were not significantly different. However, the relative shoot dry weight (RSDW) of indica rice was significantly higher than that of japonica rice and AUS, and the salt tolerance of temperate japonica rice seedlings was significantly higher than that of tropical japonica rice and admixed japonica rice. Correlation patterns of the seven salt-tolerance-related traits varied between the three subspecies. Three principal components were extracted from japonica rice, indica rice and AUS, with cumulative contribution rates of 82.587%, 80.117%, and 88.700%, respectively. Based on this, the D-values for the comprehensive evaluation of salt tolerance were calculated for each accession, and key parameters for salt tolerance were screened. It was found that RSDW is a common key indicator affecting the salt tolerance of rice seedlings, while RSH and RRDW are shared by japonica rice and AUS, and STS is the common key parameter for indica rice and AUS. In the three subspecies, high-D-value accessions and low-D-value accessions were selected to analyze root characteristics, ion balance, reactive oxygen species accumulation, and osmotic regulation substance content under salt stress. The root total number (RTN), root tip number (RN), total root length (TRL), and root surface area (RSA) of high-D-value accessions in the three subspecies were significantly higher than those of the three categories of low-D-value accessions. Among the three types of high-D-value accessions, the RTN and RN of indica rice were significantly higher than those of japonica rice and AUS. The root average diameter (RAD) of indica rice and AUS was significantly higher than that of japonica rice. AUS had significantly higher surface area and volume of roots in the 0.5-1 mm diameter range than japonica rice and indica rice, while japonica rice had significantly higher root volume in the 0-0.5 mm diameter range than indica rice and AUS. In terms of ion balance, the shoot Na⁺ content (SNC) of the three types of high-D-value accessions was significantly lower than that of the three types of low-D-value accessions. Among the three types of high-D-value groups, AUS had significantly lower SNC and shoot Na⁺/K⁺ (SNK) than that of japonica rice, japonica rice had significantly lower root Na⁺ content (RNC) than AUS, indica rice had significantly higher root K⁺ content (RKC) than AUS, and japonica rice and indica rice had significantly lower root Na⁺/K⁺ (RNK) than AUS. In terms of reactive oxygen species content, among the three categories of high-D-value accessions, the hydrogen peroxide content of japonica rice was significantly lower than that of indica rice and AUS. In terms of osmoregulatory substance content, among the three types of high-D-value accessions, the soluble sugar content of indica rice and AUS was significantly higher than that of japonica rice, and the proline content of indica rice was significantly higher than that of japonica rice.【Conclusion】Significant differences were observed in the morphological and physiological characteristics of rice germplasm accessions from different subspecies under salt stress. RSDW is a common key indicator affecting salt tolerance of rice seedlings. In response to salt stress, typical salt-tolerant germplasm from japonica, indica, and AUS developed distinct combinatorial profiles of regulatory modes, which varied in their emphasis on four key aspects: root morphological characteristics, ion homeostasis, reactive oxygen species (ROS) scavenging and osmotic adjustment.

【Objective】This study aimed to develop novel glyphosate-resistant wheat germplasm using EMS mutagenesis to mitigate weed infestation in wheat fields. Resistant mutant plants were selected through field screening, and the mutation profiles of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene as well as optimal application conditions were characterized, offering a practical approach for breeding glyphosate-resistant wheat varieties.【Method】A mutant population was generated by treating newly germinated seeds of Zhenmai 9 with EMS mutagenesis. Resistant mutants were isolated through multiple rounds of glyphosate screening in the field across M₂ and M₃ generations. Promising lines, including GR1, GR19, and GR23, were identified via pedigree selection, combined with yield and resistance phenotype screening. Mutation sites in the EPSPS gene were detected by PCR amplification and sequencing, while expression levels of TaEPSPS-4A, TaEPSPS-7A, and TaEPSPS-7D were analyzed using RT-qPCR. Field trials involving different glyphosate doses and application growth stages were conducted to systematically evaluate herbicide efficacy and determine the appropriate dosage and timing for safe application.【Result】The resistance mutant frequency in the M₂ population was 6.53×10^-6. In the M₃ generation, 43 mutant plants exhibiting tolerance to 4× the recommended glyphosate dose were successfully obtained. Sequencing analysis revealed that resistant lines GR1 and GR19 harbored 5 and 3 mutation sites in TaEPSPS-7D, respectively, whereas GR23 carried 5 mutation sites in TaEPSPS-4A. Expression analysis indicated that glyphosate treatment significantly downregulated most homoeolog genes in the three mutation lines, irrespective of whether those genes carried resistance mutations. Field trials demonstrated 100% weed control efficacy across all glyphosate treatments, significantly superior to isoproturon. As the glyphosate doses increased, wheat seedling height and fresh weight showed a decreasing trend, but most differences with the untreated control were not significant, indicating no substantial adverse effects on growth. Yield analysis revealed that treatment with 1× and 2× doses did not cause significant yield reduction, whereas 4× and 8× doses led to significant reductions of 3.04% and 4.63%, respectively. Growth stage-specific trials further indicated that spraying a 2× dose of glyphosate from seedling to jointing stages had no significant impact on plant growth, but application at the booting stage significantly reduced plant height, fresh weight, and grain yield, resulting in a 6.48% yield loss.【Conclusion】The combination of EMS mutagenesis and field screening successfully generated new glyphosate-resistant wheat germplasm capable of withstanding 4× the recommended glyphosate dose. Multiple point mutations in the non-active center of the EPSPS enzyme confered enhanced glyphosate resistance without compromising yield. For practical application of such resistant varieties, the optimal weed control window is during wheat green-up (early March), using 41% glyphosate isopropylamine salt at 840-1 680 g ae·hm^-2, diluted in 450 L·hm^-2 of water, applied as foliar spray to weeds under rain-free conditions.

【Objective】The phosphatidylethanolamine-binding protein (PEBP) family serves as pivotal regulators of plant flowering, orchestrating floral transition through the coordination of photoperiodic and hormonal signaling pathways. This study systematically characterized PEBP gene family members in the ancestral Saccharum species S. spontaneum and S. officinarum, elucidating their structural architecture, evolutionary trajectories, and expression profiles to unravel the molecular mechanisms governing flowering regulation and facilitate molecular breeding strategies.【Method】The PEBP gene family was identified by performing sequence alignment of Arabidopsis and rice PEBP protein sequences against the genomes of S. spontaneum and S. officinarum, supplemented with screening using the hidden Markov model profile PF01161. Phylogenetic reconstruction, gene structure analysis, conserved motif identification, and synteny evaluation were performed using MEGA-X and TBtools. Putative cis-regulatory elements within promoter regions were predicted via the PlantCARE database. Transcriptomic profiling coupled with qRT-PCR validation delineated expression dynamics, while functional characterization of FT3 and TFL1 genes was achieved through Arabidopsis transformation.【Result】Our analysis identified 23 and 20 PEBP genes in S. spontaneum and S. officinarum, respectively, classified into three subfamilies: FT-like, TFL1-like, and MFT-like. Protein characterization revealed greater variability in S. spontaneum PEBPs (151-364 aa; 17.1-40.4 kDa) compared to S. officinarum (170-191 aa; 19.2-20.8 kDa), though both predominantly encoded hydrophilic alkaline proteins. Conserved motif analysis demonstrated stringent conservation in TFL1-like subfamily members, while MFT-like proteins exhibited remarkable structural plasticity, exemplified by elongated PEBP domains in SspMFT1.1/1.2/1.3. Gene architecture analysis showed FT-like members possessed the highest exon variability (2-5), contrasting with TFL1-like (3-4) and MFT-like (fixed 4-exon) subfamilies. Evolutionary analysis revealed whole-genome and segmental duplications as primary expansion mechanisms, with tandem duplication frequency substantially higher in S. officinarum (8%) than S. spontaneum (1%). Syntenic analysis uncovered species-specific duplication events (e.g., SspFT5.1/SspFT5.2 and SoFT12.1/SoFT12.2) and stronger conservation between S. spontaneum and sorghum. Promoter analysis identified abundant light- and hormone-responsive elements, particularly jasmonic acid and abscisic acid response motifs. Expression profiling identified two key genes, FT3 and TFL1, with contrasting expression dynamics. FT3 displayed a sustained, photoperiod-sensitive upregulation, whereas TFL1 showed an initial decrease followed by an increase and was independent of photoperiod regulation. Transgenic validation confirmed FT3 orthologs consistently accelerated flowering (~19 days early), whereas TFL1 genes functioned as floral repressors.【Conclusion】Genomic analysis revealed 23 and 20 PEBP genes in S. spontaneum and S. officinarum, respectively, phylogenetically clustered into three well-defined subfamilies (FT-like, TFL1-like, and MFT-like) that exhibited substantial structural and functional divergence. FT3 and TFL1 demonstrated opposite expression patterns during floral induction, with FT3 showing marked photoperiod responsiveness and significantly elevated transcript abundance in S. spontaneum relative to S. officinarum. Transgenic functional analysis confirmed that FT3 typically promotes flowering, whereas the TFL1 gene suppresses it.

【Objective】This study aimed to elucidate the effects of different irrigation methods on soil water-salt transport, rice yield, and water use efficiency (WUE) in salinized paddy fields in Ningxia, as well as their physiological mechanisms, so as to clarify the suitable irrigation methods for rice in this region.【Method】Using the locally dominant cultivar Ningjing 52 as the test material, a two-year field positioning experiment was conducted to systematically investigate the patterns of soil water-salt transport, rice physiological traits, yield, and WUE under conventional irrigation (CK) and different levels of alternate wetting and drying (AWD) irrigation (W1, W2, and W3 treatments). Specifically, for the AWD treatments, from the early tillering to the late grain-filling stage, the field was re-flooded after the soil water potential dropped to -10 kPa, -20 kPa, and -30 kPa under W1, W2, and W3, respectively, and this cycle was repeated. A partial least squares path model (PLS-PM) was employed to analyze the interactions among these factors.【Result】The different irrigation methods practices significantly altered soil water-salt distribution, with the 0-40 cm soil layer being the primary zone for salt leaching. Compared with CK, W1 reduced the water content in the 0-40 cm soil layer by 11.46%, increased the electrical conductivity (EC) in the 0-20 cm layer by 8.43%, and achieved a desalination rate of 6.14% in the 20-40 cm layer, significantly outperforming CK (2.21%). Physiological analysis revealed that W1 significantly increased root length, root volume, and root-shoot ratio at the heading and grain-filling stages compared with CK, enhanced root activity, total root absorption area, and active absorption area during grain filling, and improved canopy photosynthetic efficiency (SPAD value and net photosynthetic rate of rice leaves). Consequently, yield increased by 3.96%-4.75%, and WUE improved by 18.30%-19.77%. In contrast, W2 and W3 treatments led to a notable decline in soil water content, increased soil salt accumulation, inhibited root development, and reduced photosynthetic efficiency, resulting in yield reductions of 20.00%-46.46%. Further PLS-PM analysis indicated that different irrigation methods practices influenced rice canopy photosynthetic efficiency by regulating soil physicochemical properties, root morphology, and physiology, thereby directly or indirectly affecting yield. Among these factors, canopy photosynthetic efficiency was the primary driver of rice yield.【Conclusion】The alternate wetting and drying irrigation method under -10 kPa effectively coordinates water-salt distribution, improves root morphology and physiology, and enhances photosynthetic efficiency, thereby achieving water-saving and yield-increasing effects in salinized rice fields. It could serve as a suitable irrigation method for salinized soils in Ningxia.

【Objective】The objective of this study was to simulate and predict the geographical distribution of ratoon rice in Sichuan-Chongqing region under climate change, thereby providing a scientific reference for regional expansion planning, cultivar breeding, and cropping-system formulation of ratoon rice in this area.【Method】Based on the past (1981-2000) 53 and current (2001-2020) 147 distribution points and 6 environmental variables of ratoon rice, the MaxEnt model was used to simulate the changes in the planting areas and potential suitable areas, and the dominant environmental variables affecting its distribution were determined.【Result】(1) The accumulated temperature during the safe growth period (Tac), the number of days during the safe growth period (Day), the average temperature in September (Tav₉), and altitude (Alt) were the dominant environmental variables affecting the geographical distribution pattern of ratoon rice. (2) From the past (1981-2000) to the current (2001-2020), the planting areas and potential suitable areas had extended toward the northwest of the basin, with an area expansion of 0.44×10⁴ km² (69.23%) and 3.25×10⁴ km² (60.89%), which located at 28°9'-30°55' N, 103°35'-108°32' E and 28°4'-31°48' N, 103°10'-110°4' E, respectively; the highly suitable area had extended northwest and northeast, mainly located at 28°7'-31°7' N and 103°26'-107°21' E, with a high degree of coupling with the distribution and changes of the planting area. (3) From the current (2001-2020) to the future (2041-2060), the suitable area was projected to expand northwestward under SSP245 and SSP585 scenarios. The northwestern boundary was expected to reach the area south of the central Chengdu to central Guangyuan, with the total suitable area increasing by 3.69%-16.92%. The highly suitable area was projected to extend northwestward to the line connecting Dongpo District of Meishan and Dachuan District of Dazhou, advancing 1.4°N (155.65 km) northward and 0.8°E (88.94 km) westward, with the area increasing by 45.24%-65.18%. Conversely, portions of the highly suitable area in central Yibin (Sichuan) and in Qijiang, Rongchang, and Dazu (Chongqing) were expected to contract by 2.68%-11.90%. The unchanged areas were mainly concentrated in southern Sichuan and western Chongqing regions, accounting for 72.32%-88.10% of the baseline highly suitable area.【Conclusion】Climate change was generally conducive to the expansion of suitable areas for ratoon rice in the Sichuan-Chongqing region. The primary driver was the concurrent increase in accumulated temperature and number of days during the safe growth period. Priority should therefore be given to consolidating the traditional advantageous areas in southern Sichuan and western Chongqing. Expansion should proceed incrementally into the new suitable areas, notably northeastern Leshan, western and eastern Ziyang, southern Suining, southern Nanchong, southwestern Dazhou in Sichuan, as well as the most of Tongnan and northern Tongliang in Chongqing. Pilot cultivation should be encouraged in emerging potential areas, such as eastern Chengdu, Deyang, and southern Mianyang. A phased, region-specific strategy was recommended to ensure the sustainable and stable development of ratoon rice production. Concurrently, intensified efforts were needed to develop and deploy monitoring, early-warning, and risk-mitigation technologies against meteorological disasters under continued global warming.

【Objective】Phosphorus is a critical nutrient element for crop growth and development, directly influencing photosynthesis and physiological functions. Accurate monitoring of leaf phosphorus content is essential for efficient crop management and yield prediction. In this study, an ensemble hyperspectral dimensionality reduction model was proposed for estimating leaf phosphorus content based on different spectral preprocessing methods combined with various spectral dimensionality reduction techniques, in order to provide a theoretical basis for hyperspectral diagnosis of crop phosphorus nutrition.【Method】Through two years of field experiments, canopy spectral reflectance and leaf phosphorus content were collected for winter wheat during four key growth stages (jointing, heading, flowering, and grain filling) under three nitrogen application levels. Derived spectral features were generated using De-trending transformation, standard normal variate transformation, and first-order derivative reflectance transformation. Spectral dimensionality reduction was performed using successive projections algorithm (SPA), least absolute shrinkage and selection operator (LASSO), and competitive adaptive reweighted sampling (CARS). Single estimation models and integrated estimation models were constructed by combining random forest regression (RF), support vector regression (SVR), and partial least squares regression (PLSR).【Result】The leaf phosphorus content-sensitive spectral features were primarily concentrated in the visible, near-infrared, and short-wave infrared bands. Compared to original spectral reflectance and other derived spectral features, first-order derivative-derived spectral features demonstrated significant advantages in detecting leaf phosphorus content. Among the single models, the highest estimation accuracy was achieved when CARS was used for dimensionality reduction to select sensitive first-order derivative-derived features, driving the RF algorithm, with R²=0.843 and RMSE=0.038% in the training dataset, and R²=0.756 and RMSE=0.057% in the testing dataset. The integrated hyperspectral dimensionality reduction estimation further improved model accuracy. The integrated model driven by first-order derivative-derived spectral features and constructed using RF regression achieved the best estimation performance, with R²=0.932 and RMSE=0.025% in the training dataset, and R²=0.817 and RMSE=0.049% in the testing dataset.【Conclusion】Ensemble hyperspectral dimensionality reduction method effectively enhanced the estimation accuracy of leaf phosphorus content in winter wheat, providing theoretical support for large-scale monitoring of crop nutrition and growth under different hyperspectral remote sensing platforms, crop types, and growth conditions in the future.

【Objective】The host adaptability of Bemisia tabaci is closely associated with the plasticity of its lipid metabolism, particularly fatty acid metabolism. Fatty acid elongases (ELOs) are key regulatory components in fatty acid biosynthesis and modification. A comprehensive characterization of the ELO gene family in B. tabaci will contribute to elucidate the metabolic mechanisms underlying its nutritional adaptation, growth, and reproduction, and to identify novel target gene resources for sustainable green pest management strategies.【Method】Based on the B. tabaci MED genome and ELO sequences from other insects, ELO genes in B. tabaci were identified through multiple sequence alignment, 22 BtELO coding sequences were amplified and cloned using RT-PCR. Bioinformatics analyses were conducted to determine gene structure and protein physicochemical properties, and a maximum-likelihood phylogenetic tree was constructed to examine the evolutionary relationships between BtELOs and ELO genes from other Hemipteran insects. The temporal and spatial expression patterns of BtELOs in different developmental stages (egg, 1st-4th instar nymphs, and adults) and in various adult tissues (head, thorax, and abdomen) were analyzed using quantitative real-time PCR (qRT-PCR).【Result】A total of 22 BtELOs CDS were successfully identified and cloned, ranging from 714 to 1 296 bp. These genes, located on 10 genomic SCAFFOLDs, were sequentially designated BtELO1 through BtELO22 based on their linear arrangement. The encoded proteins, comprising 237 to 431 amino acids, are generally hydrophobic, contain 6-7 transmembrane domains, and are predicted to localize in the endoplasmic reticulum. Sequence alignment and phylogenetic analyses revealed that BtELO proteins possess the typical ELO conserved domain and histidine cluster (HXXHH). The sequence similarity among BtELO family members was as high as 76%. The BtELOs were grouped into 7 major evolutionary clades with clear phylogenetic clustering patterns, indicating conserved evolutionary relationships, with some genes forming independent clades indicative of gene duplication events. Spatiotemporal expression profiling revealed that the expression of BtELOs exhibited clear stage- and tissue-specific patterns in B. tabaci, indicating that these genes may perform diverse biological functions in this species.【Conclusion】The 22 BtELOs identified in B. tabaci contain the typical elongase domain and the conserved HXXHH motif. All BtELOs are expressed in various developmental stages and tissues of B. tabaci. Several genes exhibit high expression in eggs and adult abdomens, suggesting potential roles in reproductive processes, whereas those highly expressed during the nymphal stages may be associated with growth, development, and molting.

【Objective】This study aims to reveal the spatiotemporal variation of five major grass weed species, including Lolium multiflorum, in winter wheat fields of the Huang-Huai-Hai region over the past decade, and to provide a basis for regional weed monitoring, early-warning and precision management.【Method】Two rounds of systematic surveys were conducted in winter wheat fields across the Huang-Huai-Hai region in 2013 and 2023 using an inverted “W”-shaped nine-point sampling method. The distribution ranges and infestation levels of five dominant grass weeds, including Aegilops tauschii, Bromus japonicus, Lolium multiflorum, Alopecurus myosuroides and Avena fatua, were recorded. The relationships between relative abundance (RA) and longitude/latitude were analyzed to characterize spatiotemporal distribution patterns.【Result】The spatiotemporal changes in grass weeds in winter wheat fields of the Huang-Huai-Hai region were mainly reflected in the following aspects: (1) The relative abundance of four grass weeds, L. multiflorum, A. tauschii, B. japonicus and A. myosuroides, increased continuously, whereas that of A. fatua decreased slightly. In 2013, B. japonicus and A. tauschii showed the highest RA values in the region, together accounting for more than 15%, followed by A. fatua (2.51%), while L. multiflorum and A. myosuroides both had RA values below 2.5%. By 2023, the RA of A. tauschii (11.66%) and B. japonicus (11.22%) increased markedly. The maximum increase observed for A. tauschii was 8.72%, whereas B. japonicus exhibited increases ranging from 0.43% to 10.44%. The regional mean RA of L. multiflorum increased to 2.88%, exceeding that of A. fatua (2.14%) and becoming the third most abundant species. (2) Spatially, the infested area of L. multiflorum, A. tauschii, B. japonicus and A. myosuroides expanded continuously, while the distribution range of A. fatua shrank slightly. A. tauschii and B. japonicus expanded continuously eastward and southward from their traditional high-incidence belts in the western and northern Huang-Huai-Hai region; by 2023 they almost covered all major winter wheat production areas across the entire region, and relatively stable populations had formed in previously blank or sporadically infested areas such as the Huaibei region of Anhui and Jiangsu as well as Tianjin. In 2013, L. multiflorum and A. myosuroides occurred only sporadically in a few prefecture-level cities; ten years later, L. multiflorum was recorded in about 60% of the surveyed prefecture-level cities, rapidly shifting from “localized point occurrence” to a pattern of “southern concentration with regional spread”, and forming new high-incidence belts in central-southern Henan, northern Anhui, northern Jiangsu and the Guanzhong Plain, indicating strong expansion momentum and substantial potential risk. A. myosuroides formed concentrated high-incidence areas in the Guanzhong Plain, central-southern Henan, northern Anhui and central-southern Hebei, with its overall pattern changing from “point-like occurrence” to “patch-like expansion”. In contrast, the overall distribution range of A. fatua decreased; it was no longer recorded in some central and northern prefecture-level cities, and its main high-incidence belt shifted from the previous “wide distribution in southern and western areas” to localized concentration in central-southern Henan, northern Anhui and the Guanzhong Plain, showing a “southward contraction” pattern. (3) Correlation analyses showed that in 2013 the RA of A. tauschii was significantly negatively correlated with longitude, whereas in 2023 it was significantly positively correlated with latitude, indicating a weakened east-west gradient and an enhanced north-south gradient. The RA of B. japonicus increased highly significantly with latitude in both surveys, and in 2023, also showed a significant increasing trend with longitude. The RA of L. multiflorum and A. fatua generally decreased with increasing latitude and longitude, while A. myosuroides showed no consistent or significant correlation.【Conclusion】Over the past decade, major grass weeds in winter wheat fields of the Huang-Huai-Hai region have undergone marked spatiotemporal expansion, accompanied by increasing relative abundance. These changes are driven by the combined effects of alien invasion, conservation tillage, long-term reliance on single-site-of-action herbicides, and cross-regional movement of agricultural machinery and seeds. Accordingly, region-specific systems for weed monitoring, early warning, and integrated management, together with optimized tillage practices and herbicide mode-of-action rotations, are required to enable precision control of grass weeds across the Huang-Huai-Hai winter wheat system.

Greenhouse gas emission inventories specifically target anthropogenic components. Consequently, internationally recognized accounting methodologies deduct natural background emissions when quantifying nitrous oxide from croplands and methane (CH₄) from flooded lands. However, in compiling paddy CH₄ emission inventories, the entirety of CH₄ emitted from rice paddies is currently accounted for as anthropogenic contribution from rice cultivation. Here, through synthesis of empirical research, meta-analysis of published literatures, and model simulations, we analyzed the origins and cultivation history of rice paddies in China, key drivers of CH₄ emissions, and fundamental accounting methodologies used in inventory compilation. The goal was to isolate and estimate the natural and anthropogenic contributions to CH₄ emissions from rice paddies in China. Our results reveal that rice paddies possess dual attributes of both wetlands and croplands. Their CH₄ emissions comprise both natural and anthropogenic components and should not be wholly attributed to human activities. Paddy CH₄ emissions were found to be approximately 72.2% to 123.6% of those from their adjacent natural wetlands, indicating that converting low-lying lands and marshes to rice cultivation does not necessarily increase CH₄ emissions. Global wetland restoration practices further demonstrate that water management regimes mimicking paddy field conditions during the growing season (groundwater depth 0-20 cm) optimally balance CH₄ mitigation with soil carbon sequestration and biodiversity conservation, underscoring the rice cultivation potential as a climate-smart land-use practice. Estimates based on machine learning models suggest that natural emissions constitute more than 36% of total paddy CH₄ fluxes, a proportion too significant to ignore. Therefore, analogous to the IPCC accounting methodologies for nitrous oxide from croplands and CH₄ from flooded lands, natural background emissions should be deducted when compiling paddy CH₄ inventories. As a responsible global leader in rice production, China should proactively shape international discourse on CH₄ inventory compilation and mitigation strategies. We propose initiating methodological updates and foundational data enhancement by: (1) Strengthening theoretical research to refine accounting methodologies and ensure scientific rigor in inventories; (2) Enhancing foundational data collection through intensified in-situ monitoring and improved model estimation to reduce inventory uncertainty; and (3) Fostering international collaboration and exchange to elevate the influence of China and other major rice-producing nations in shaping global standards for paddy CH₄ accounting and inventory compilation, thereby synergistically advancing carbon mitigation and sequestration actions in rice ecosystems.

【Objective】This study explored the effects of the application of organic materials on soil pH, microbial biomass and microbial entropy, so as to provide a scientific basis for the improvement of arable land quality.【Method】Based on the meta-analysis, 1 296 sets of data from 224 literatures around the world were integrated to comprehensively analyze the differences in soil pH, microbial biomass carbon (MBC), nitrogen (MBN), microbial entropy carbon (qMBC), and nitrogen (qMBN) under the conditions of organic material application measures (type, application amount, and application years), climate factors (annual average temperature, precipitation), and initial soil properties (pH value, organic carbon content).【Result】After the application of organic materials, the soil pH value increased significantly by 0.23 units, increased by 4.0%, while MBC, MBN, qMBC and qMBN increased by 46.8%, 54.0%, 16.4% and 14.9%, respectively. Compared with chemical fertilizer, soil pH, MBC, MBN, qMBC and qMBN increased by 5.9%, 53.4%, 13.2%, 79.9% and 38.2%, respectively. The effect of increasing soil pH was the best when the amount of manure application was more than 10 t∙hm^-2∙a^-1 and the application period exceeded 10 years; however, the soil microbial biomass index could be significantly improved when the amount of fertilizer was more than 40 t∙hm^-2∙a^-1 and the application period was 3-10 years. Under the climate conditions of annual average temperature >16 ℃ and annual precipitation >1 200 mm, the effect of applying organic materials on improving soil pH was better, especially in soils with initial soil pH value of 4.5-5.5 and organic carbon content (SOC) >12 g∙kg^-1; however, under the climate conditions of 8-16 ℃ annual average temperature and annual precipitation <600 mm, the application of organic materials had better effect on the improvement of MBC, MBN, qMBC and qMBN in weakly alkaline soil (pH>7.5) with SOC≤12 g∙kg^-1. The random forest model showed that the effects of applying organic materials on soil pH, MBC, MBN and microbial entropy were affected by soil initial pH and SOC, application measures of organic materials and climate conditions, respectively. The partial least squares path model further proved that the application measures of organic materials, climate conditions and initial soil properties affect microbial biomass and microbial entropy by adjusting pH value.【Co nclusion】Organic materials most effectively elevated soil pH in acidic with high-SOC soils (pH≤5.5, SOC>12 g∙kg^-1), which enhanced microbial biomass and microbial quotients in alkaline with low-SOC soils (pH>7.5, SOC≤12 g∙kg^-1). The regulation of soil pH, microbial carbon and nitrogen, and microbial quotients was primarily controlled by initial soil properties, organic material application measures, and climatic conditions.

【Objective】Nitrogen leaching is one of the significant sources of nitrate pollution in groundwater in vegetable-growing areas with facilities. This study aimed to explicit the characteristics of nitrogen leaching in facility vegetable fields for the calculation of agricultural non-point source pollution and achieving green, efficient and sustainable vegetable production.【Method】This study took the one-year two-crop system of facility tomato and cucumber as the research object, and conducted an 8-year field experiment from 2016 to 2023 in Yucheng City, Shandong Province, to investigate the effects of different water and fertilizer management strategies on nitrogen leaching, yield, water and fertilizer use efficiency in facility vegetable fields.【Result】Under the rotation mode of facility tomato and cucumber, the peak leaching flow mainly occurred in March and October, which were basically during the fruiting periods; the runoff yield of peak season accounted for more than 34.6% of the annual flow. The optimized water and fertilizer management (OPTW) significantly reduced the leaching flow in facility vegetable fields by more than 32.6%, but had no significant effect on the leaching intensity. The proportion of total soluble nitrogen in the leachate of each treatment was more than 70.0%, which was the main form of nitrogen loss. Compared with the traditional water and fertilizer management (FP), the optimized fertilization (OPT) reduced the total nitrogen leaching by 24.7%, increased the annual vegetable yield by 3.2%, and improved the water and fertilizer use efficiency by more than 2.7%, while OPTW significantly reduced the total nitrogen leaching by 49.6%, increased the annual yield of facility vegetables by 19.6%, and improved the water and fertilizer use efficiency by more than 55.5%. The total nitrogen leaching coefficients of OPT and OPTW were 24.9% and 16.3%, respectively, with no significant difference between them, and OPTW was 31.9% lower than FP.【Conclusion】The optimized water and fertilizer integrated management could ensure vegetable yield increase while reducing nitrogen emissions and improving water and fertilizer use efficiency, providing a reliable technical support for reducing the risk of nitrogen leaching in facility vegetable fields. However, in subsequent research or actual production, the irrigation regime needed to be further optimized, and agronomic measures should be added, such as nitrogen form regulation and enhancement of soil water and fertilizer retention capacity.

【Objective】The objectives of this study are to explore the response mechanism of citrus yield, quality and water-nitrogen use efficiency to water and nitrogen under surge-root irrigation in western Hubei, and to propose a water-nitrogen management mode for high-quality and high-yield of citrus, so as to provide a theoretical basis for the scientific management of water and nitrogen in citrus industry.【Method】6a-old Newhall navel orange was used as the test material, and the surge-root irrigation technology was adopted, and two factors of irrigation and nitrogen application were established. The two irrigation levels were full irrigation (FI: 70%-85%θ_f, θ_f is the field water holding capacity) and deficit irrigation (DI, 70%FI), and the three nitrogen application levels were high nitrogen (NH: 300 kg·hm^-2), medium nitrogen (NM: 225 kg·hm^-2) and low nitrogen (NL: 150 kg·hm^-2), respectively. The effects of different water and nitrogen treatments on the yield, fruit quality and water-nitrogen use efficiency of citrus in western Hubei were analyzed, and the yield, quality and water-nitrogen use efficiency of citrus were comprehensively evaluated based on the game theory combination weighted TOPSIS method.【Result】Irrigation and nitrogen application under surge-root irrigation had significant effects on yield, single fruit weight, irrigation water use efficiency (IWUE), nitrogen partial factor productivity (NPFP), fruit diameter and fruit quality of western Hubei citrus (P<0.05). Moderate deficit irrigation and reduced nitrogen application were beneficial for improving the yield, quality and water-nitrogen utilization efficiency of citrus fruits. Among the treatments, the yield, single fruit weight, IWUE, fruit transverse and longitudinal diameter of DINM treatment were the largest, which were 24 458.38 kg·hm^-2, 311.45 g, 40.48 kg·m^-3, 89.02 mm and 87.18 mm, respectively. This represented an increase of 2.26%-25.66%, 1.92%-16.04%, 2.82%-78.46%, 8.85%-20.74%, and 3.33%-17.76% compared to other treatments. However, the DINL treatment exhibited the highest NPFP at 143.80 kg·kg^-1. Under deficit irrigation conditions, the fruit moisture content was lower than that under full irrigation; however, the fruit hardness, soluble solid content, soluble reducing sugars, titratable acidity, vitamin C content, edible rate, and sugar-acid ratio were higher than those under full irrigation. Under full irrigation, the soluble solid content, soluble reducing sugars, vitamin C content, and sugar-acid ratio decreased with the reduction of nitrogen application. Compared with the FINH treatment, the FINM treatment decreased by 8.01%, 12.06%, 7.70%, and 14.55%, respectively, while the FINL treatment decreased by 14.97%, 18.19%, 10.54%, and 16.25%. Under deficit irrigation, the fruit moisture content, soluble solid content, soluble reducing sugars, titratable acidity, vitamin C content, edible rate, and sugar-acid ratio showed a trend of first increasing and then decreasing with the reduction of nitrogen application. Compared with DINM treatment, the DINH treatment decreased by 1.63%, 6.75%, 13.65%, 6.35%, 8.04%, 4.11%, and 9.18%, respectively, and the DINL treatment decreased by 3.30%, 14.55%, 20.55%, 4.76%, 10.98%, 7.50%, and 10.25%, respectively. The comprehensive weights of indexes were determined based on the game theory combination weighted TOPSIS method. The comprehensive weights of citrus yield, NPFP, IWUE and fruit quality were 0.399, 0.153, 0.104 and 0.344, respectively. The comprehensive evaluation results showed that the comprehensive score of DINM treatment was the highest, followed by DINH treatment, and the score of FINL treatment was the lowest.【Conclusion】The optimal water-nitrogen coupling mode of citrus in western Hubei under surge-root irrigation is 70%FI (FI: 70%-85%θ_f) and NM (225 kg·hm^-2).

【Objective】The leaves of Vaccinium species are the main by-products in blueberry cultivation, which are rich in polyphenolic active compounds, but their resource values have not been fully developed and utilized. This study aimed to systematically investigate the accumulation patterns of polyphenolic components and their antioxidant activities in leaves at different developmental stages across 34 Vaccinium species, including wild resources and commercial cultivars. The objective was to identify germplasm with high nutritional value, thereby providing a theoretical basis for the high-value utilization of Vaccinium leaves and the development of functional products.【Method】Young (tender) leaves in spring, mature leaves and senescent leaves in winter from 34 Vaccinium species were used as experimental materials to detect the contents of total flavonoids, quercetin, anthocyanins, and proanthocyanidins. Antioxidant activities were comprehensively evaluated by three in vitro methods of hydroxyl radical (·OH) scavenging rates, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging rates, and ferric reducing antioxidant power (FRAP). Correlation analysis and principal component analysis (PCA) were applied to elucidate the relationships between polyphenolic components and antioxidant activities.【Result】Polyphenol contents and antioxidant activities in Vaccinium leaves were generally high and exhibited significant variations among species, cultivars, and leaf developmental stages. The average total flavonoid contents of young, mature, and senescent leaves were 189.92, 89.05 and 99.51 mg·g^-1 DW, respectively. Notably, young leaves of V. duclouxii (YNY316) exhibited an exceptionally high total flavonoid content of 561.43 mg·g^-1 DW. The average quercetin contents were 4.51, 12.56 and 8.95 mg·g^-1 DW, with mature leaves of V. mandarinorum (MFH4) showing the highest level (38.85 mg·g^-1 DW). The average anthocyanin contents were 0.83, 1.41 and 1.70 mg·g^-1 DW, while the average proanthocyanidin contents were 36.52, 38.45 and 44.42 mg·g^-1 DW. Antioxidant activity assessment revealed that senescent leaves showed the highest ·OH scavenging rate (65.14%) and FRAP value (1.23), whereas mature leaves exhibited the strongest ABTS radical scavenging capacity (33.66%). Correlation analysis indicated that quercetin contents in mature and senescent leaves were significantly positively correlated (P<0.01) with FRAP values and ABTS radical scavenging rates, indicating that quercetin is a major contributor to the antioxidant activity of Vaccinium leaves. Furthermore, wild resources such as V. duclouxii, V. trichophyllum, and V. mandarinorum, along with blueberry cultivars including ‘Eureka' ‘Beckyblue' and ‘Sringhigh', exhibited superior performance across multiple indices.【Conclusion】Wild Vaccinium germplasm and selected superior cultivars are rich in polyphenols, particularly flavonoids and proanthocyanidins, and exhibit remarkable antioxidant potential. The optimal developmental stages for leaf harvesting aimed at different functional components were clarified (e.g., young leaves for flavonoid extraction and mature leaves for quercetin extraction). These findings provide a theoretical foundation for the breeding of high-polyphenol blueberry cultivars and the high-value utilization of Vaccinium leaf resources.

【Objective】The thermostability and potential safety risks of Bacillus may pose a threat to the quality of honey products. Therefore, it is necessary to optimize the pre-treatment process for Bacillus detection in honey, to clarify the contamination characteristics of Bacillus, and to evaluate the risks in the processing chain, aiming to provide a theoretical basis for establishing a scientific and effective quality and safety control system.【Method】To improve the accuracy of Bacillus detection results in honey, this study selected a temperature range of 60-80 ℃ to carry out heat treatment experiments, and systematically explored the optimal process conditions for simultaneously achieving efficient inactivation of miscellaneous bacteria and retention of Bacillus spore concentration. Quantitative counting of Bacillus was performed on 150 commercial honey samples and 150 raw honey samples, followed by further strain isolation and purification. Meanwhile, Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) and next-generation sequencing based bacterial genome sequencing were combined to identify the species of Bacillus in honey. The species and detection rates of Bacillus in each honey sample were statistically analyzed, and food safety risk assessment was conducted accordingly. Furthermore, by simulating the honey processing procedures, the study investigated the effect of heat treatment at 40-60 ℃ on the growth of Bacillus cereus spores in honey and clarified its variation trend.【Result】Heat treatment at 80 ℃ for 10 min could completely inactivate the interfering bacteria (Escherichia coli and Saccharomyces cerevisiae) in honey, while maintaining the spore viability at the same order of magnitude. Statistical analysis was conducted on the results of Bacillus quantification and identification in 150 commercial honey samples and 150 raw honey samples. The results showed that the total detection rate of Bacillus in commercial honey was 38.7%, dominated by Bacillus cereus (20.7%), Bacillus subtilis (12.7%) and Bacillus pumilus (11.3%). By contrast, the total detection rate of Bacillus in raw honey was 23.3%, mainly including Bacillus cereus (16.7%), Bacillus pumilus (8.0%) and Bacillus licheniformis (3.3%). A comparison of the samples with the highest Bacillus concentration in commercial and raw honey indicated that all of these samples were subject to single contamination by Bacillus cereus. In addition, experiments simulating the heat treatment conditions (40-60 ℃) during honey processing demonstrated that the number of Bacillus cereus spores was positively correlated with temperature-time, namely, the spore count exhibited a significant upward trend with the increase of treatment temperature and extension of treatment duration. Correlation analysis of Bacillus species indicated that Bacillus contamination in commercial honey was primarily derived from raw honey. The detection of environmental strains indirectly demonstrated that honey was susceptible to microbial contamination throughout the whole chain, including honey collection by bees, raw honey harvesting and subsequent processing procedures.【Conclusion】Heat treatment at 80 ℃ for 10 min was identified as the optimal pre-treatment protocol for Bacillus detection in honey. Bacillus cereus was confirmed as the primary hazard bacterium in honey. It was recommended that honey production enterprises listed Bacillus as one of the core monitoring indicators for the quality control of raw honey.

【Background】The Chinese Holstein is the primary dairy cattle breed in China, and its production performance is directly linked to the economic sustainability of the industry. Birth weight and weaning weight are key early-life traits used to evaluate calf health and future milk production potential. A systematic understanding of their genetic characteristics is essential for effective genetic improvement. However, comprehensive studies evaluating the genetic parameters, breeding values, and genetic trends of birth weight and weaning weight in large Chinese Holstein populations remain limited.【Objective】This study aimed to investigate the non-genetic factors influencing these traits, estimate their genetic parameters and breeding values, and provide a theoretical basis for efficient genetic selection in Chinese Holstein cattle.【Method】Complete production records from a large-scale Holstein farm in Hebei Province between 2017 and 2023 were collected. Following rigorous data cleaning and tracing of complete three-generation pedigrees, valid birth weight and weaning weight data were obtained from 15 672 Holstein calves, derived from 5 798 dams and 100 sires. The GLM procedure in SPSS 26.0 was used to analyze the effects of fixed factors (including birth year, birth season, parity, sex, and calving type) on birth weight and weaning weight. Variance components for both traits were estimated using a two-trait animal model with the AI-REML and EM algorithms in DMU software. Heritabilities and the genetic correlation between the two traits were subsequently calculated. Breeding values for all individuals were estimated using the BLUP method under an animal model. The effectiveness of breeding practices was evaluated by ranking sires based on estimated breeding values, comparing progeny performance, and analyzing genetic trends.【Result】Descriptive statistics indicated mean values of (40.05±4.53) kg for birth weight and (100.31±8.60) kg for weaning weight. Fixed effects analysis revealed that birth year, season, parity, sex, and calving type had highly significant effects (P<0.01) on both traits. The direct heritability estimates were 0.57 (0.04) for birth weight and 0.39 (0.02) for weaning weight, indicating high heritability for both traits. A moderate-to-high positive genetic correlation (0.46±0.04) was observed between birth weight and weaning weight. Breeding value estimation demonstrated high accuracy, with progeny of the top ten sires showing significantly higher mean birth weight (40.26 kg) and weaning weight (104.41 kg) compared to those of the bottom ten sires (39.08 kg and 97.90 kg, respectively). Genetic trend analysis revealed considerable fluctuation in average breeding values for both traits over birth years, with an overall declining trend.【Conclusion】Birth weight and weaning weight in Chinese Holstein cattle are influenced by factors such as birth year and sex. The results confirm the high heritability of both traits and a moderate-to-high genetic correlation between them, supporting their simultaneous selection in breeding programs. Sires exhibiting superior performance in early growth traits were identified, and it is recommended to prioritize the use of bulls with high breeding values for weaning weight and moderate breeding values for birth weight in practical breeding. This study clarifies the genetic basis of early body weight traits in Chinese Holstein cattle, providing a theoretical foundation and data support for genetic improvement and the formulation of balanced breeding strategies for birth weight and weaning weight.

【Background】Staphylococcus aureus is a common gram-positive pathogenic bacterium capable of causing various infectious diseases and toxin-mediated illnesses. As central effectors of innate immunity, macrophage play a critical role in eliminating S. aureus. However, S. aureus can evade immune clearance by inducing macrophage apoptosis. Guanylate-binding protein 2 (GBP2), an interferon-inducible GTPase, participates in host immune regulation against intracellular pathogens, but its specific functions and regulatory mechanisms in S. aureus-induced macrophage apoptosis remain unclear.【Objective】This study aimed to investigate the regulatory role of GBP2 and its underlying molecular mechanisms in macrophage apoptosis during S. aureus infection to reveal novel immune evasion strategies of S. aureus, so as to provide a theoretical basis for developing new anti-S. aureus therapeutic strategies.【Method】Small interfering RNA (siRNA) technology was used to establish a GBP2-knockdown model in the murine macrophage cell line RAW264.7. After S. aureus infection, the expression levels of the target proteins in macrophages were analyzed by western blotting. These proteins included GBP2, key apoptosis-related proteins (Cleaved-Caspase3 and Cleaved-PARP1), regulatory proteins (Bax and Bcl-2), and key molecules of the MAPK signaling pathway (total JNK, ERK, p38, and their phosphorylated forms p-JNK, p-ERK, and p-p38). Changes in GBP2 mRNA expression levels were measured using quantitative real-time polymerase chain reaction. The intracellular localization and expression of GBP2 were observed using immunofluorescence staining. Apoptosis rates were quantified by flow cytometry using the Annexin V-FITC/PI double-staining assay. All experiments included appropriate controls. Differences between groups were analyzed using one-way analysis of variance, with statistical significance set at P<0.05.【Result】S. aureus infection significantly increased both GBP2 protein and mRNA expression levels in RAW264.7 macrophages (P<0.001). Concurrently, infection activated the intrinsic apoptotic pathway, as evidenced by significantly increased expression of Cleaved-Caspase3 and Cleaved-PARP1 (P<0.001), upregulation of the pro-apoptotic protein Bax, downregulation of the anti-apoptotic protein Bcl-2, and a significantly elevated Bax/Bcl-2 ratio (P<0.001). Flow cytometry confirmed a significantly higher apoptosis rate in the S. aureus-infected group than that in the control group (P<0.001). Furthermore, S. aureus infection markedly activated the MAPK signaling pathway, as indicated by significantly increased levels of p-JNK, p-ERK, and p-p38 (P<0.001). When compared with S. aureus infection alone, the siRNA-GBP2+S. aureus group exhibited significant inhibition of the apoptotic phenotype; Cleaved-Caspase3 and Cleaved-PARP1 expression levels were markedly reduced (P<0.001), the Bax/Bcl-2 ratio was significantly decreased (P<0.001), and the apoptosis rates were also significantly reduced (P<0.001). Simultaneously, GBP2 knockdown significantly suppressed the activation of the MAPK pathway, leading to reduced phosphorylation of JNK, ERK, and p38 (P<0.001).【Conclusion】GBP2 acted as a regulator of S. aureus-induced macrophage apoptosis, likely through modulation of MAPK pathway activation. These findings enhanced our understanding of S. aureus pathogenesis and host-pathogen interactions and reveal a novel function of GBP2 in the immune response to bacterial infection. Targeting GBP2 or its MAPK-mediated apoptotic signaling pathway might represent a promising therapeutic approach to combat S. aureus infection, protect host immune cells, and enhance pathogen clearance.