This research focused on four new alfalfa （Medicago sativa） lines （P1， P2， P3， and P4） and local M.sativa cultivar 'Longdong' to explore the changes and response mechanisms under low-temperature conditions. The morphological， physiological， and photosynthetic parameters of seedlings were measured at 0 d （CK）， 1 d， 13 d， and 20 d under low-temperature stress （4 °C）. The results showed that as the duration of low temperature stress increased， plant height， aboveground and belowground biomass， root-shoot ratio， root activity， chlorophyll a， chlorophyll b， carotenoids， total chlorophyll content， transpiration rate， net photosynthetic rate， stomatal conductance， and the contents of auxin， zeatin， and gibberellin in aboveground and belowground were decreased significantly （P<0.05）. Water use efficiency， malondialdehyde content， and aboveground and belowground abscisic acid were significantly risen （P<0.05）. The stomatal limitation value， along with the activities of peroxidase， superoxide dismutase， and catalase showed an initial increase followed by decrease， reaching their peak at 13 d under stress. In contrast， the intercellular CO₂ concentration decreased initially and then increased， with the minimum value occurring at 13 d under stress. The comprehensive evaluation with the membership function indicated that cold resistance was ranked as P4>P2>P1>P3>'Longdong'. Linear regression analysis revealed that aboveground gibberellin， plant height， underground gibberellin， and belowground zeatin can be the preferred indices for evaluating the cold resistance of alfalfa seedlings. These findings provide a theoretical basis for breeding new alfalfa cultivars with cold-resistant.

As a high-value cool-season grass species cultivated worldwide，perennial ryegrass （Lolium perenne L.） frequently faces various abiotic stresses. Fructans are the primary reserve carbohydrates in perennial ryegrass，which play a crucial role under abiotic stress conditions and significantly enhance stress tolerance. This article reviews research progress on fructan metabolism in perennial ryegrass in China and internationally，focusing on its biosynthesis and degradation pathways，as well as the regulatory mechanisms of certain biomolecules on fructan metabolism. In addition，metabolic changes and underlying mechanisms of fructans in perennial ryegrass were illustrated under various abiotic stresses including drought，low temperature，salinity，waterlogging，nitrogen deficiency，and mowing，with prospects on future research directions.

To investigate salt tolerance in alfalfa （Medicago sativa） germplasm， 30 alfalfa accessions of diverse origins were subjected to salt stress （200 mmol/L NaCl） for 15 days. Responses were evaluated through changes in seedling morphology， photosynthetic parameters， and physiological indices compared to control plants （CK， irrigated with Hoagland nutrient solution）. The results demonstrated that NaCl treatment decreased plant height， leaf area， leaf relative water content， root activity， shoot dry weight， chlorophyll a， chlorophyll b， transpiration rate， stomatal conductance， net photosynthetic rate， intercellular CO₂ concentration， water use efficiency， catalase （CAT） activity， and potassium （K⁺） content relative to CK. Conversely， root dry weight， root-to-shoot ratio， stomatal limitation value， proline content， malondialdehyde （MDA） content， peroxidase （POD） activity， superoxide dismutase （SOD）， sodium （Na⁺） content， and the Na⁺/K⁺ ratio exhibited increases. Regression analysis identified stomatal conductance， root activity， root-to-shoot ratio， and Na⁺ content as critical indicators for salt tolerance evaluation. The clustering analysis based on the comprehensive evaluation value of the membership function shows that the 30 alfalfa accessions were classified into four distinct tolerance categories： high salt-tolerant， moderately salt-tolerant， low salt-tolerant， and salt-sensitive. Accessions 7254 and 7657 exhibited high salt tolerance.

Functional microorganisms are essential for promoting plant growth in the desert steppe ecosystem of Inner Mongolia， offering valuable theoretical support and a scientific foundation for grassland ecological restoration and sustainable management. However， comprehensive research on the species diversity and plant growth-promoting mechanisms of these microorganisms within the rhizosphere and endosphere of forage grasses in this region remains limited. This study employed high-throughput sequencing technology to provide a preliminarily analysis of the rhizosphere bacterial community composition associated with 12 dominant forage grass species in the desert steppe. Five bacterial strains （A1-A3 and B1-B2， respectively）were isolated from endosphere and rhizosphere and screened using nutrient-modified selective media based on the soil nutrient conditions of the experimental site. These strains were identified as Bacillus sp. （B1 and B2）， Promicromonospora sp. （A1）， and Streptomyces sp. （A2 and A3）. Functional characterization revealed these strains exhibited strong nutrient-solubilizing capabilities. Strain A2 demonstrated a soluble phosphorus content of 164.51 mg/L in inorganic phosphorus fermentation broth， while strain A3 showed a soluble phosphorus content of 17.43 mg/L in organic phosphorus fermentation broth. All strains exhibited significant potassium-solubilizing activity. Furthermore， they produced plant growth-promoting hormones and displayed ACC deaminase activity. Strain B1 produced auxin at 26.08 μg/L. ACC deaminase activity ranged from 32.20 to 40.05 U/L for strains A1， A2， A3， and B1. All five strains promoted the growth of Neopallasia pectinata seedlings， particularly in enhancing radicle growth.

Salt stress leads to the accumulation of reactive oxygen species （ROS） in plants， causing damage to plant cells. However， the enzymatic antioxidant system is responsible for scavenging ROS in plant cells and protecting cells from ROS damage. At present， there are few functional analyses of genes related to ROS-scavenging enzymes in alfalfa （Medicago sativa） in response to salt stress. Based on the transcriptome data of roots and leaves of salt-tolerant alfalfa cultivar （GIB） and salt-sensitive cultivar （LS） under salt stress， this study identified 28 differentially expressed genes related to ROS-scavenging. Twenty-eight genes are distributed on 19 chromosomes， belonging to five gene families： MsGST， MsPOD， MsAOX， MsGRX and MsPrdx， among which MsGST （12） and MsPOD （11） families account for the largest proportion. The physicochemical properties of ROS scavenging enzyme proteins were different among the members of each gene family. There were highly similar conserved motifs in the members of the gene family. Phylogenetic analysis showed that MsGSTUs and MsPODs were located in the branches defined by Tau and AtPERs in Arabidopsis thaliana， respectively， suggesting that they had similar evolutionary processes and similar functions.Real-time fluorescence quantitative PCR analysis showed that the expression levels of MsGSTU26， MsPOD2 and MsPOD4 genes in GIB leaves under salt stress were significantly higher than those in LS， and the promoter regions of the three genes had elements （G-box and CGTCA-motif） related to adverse stress. It indicated that the MsGSTU26， MsPOD2 and MsPOD4 genes may be involved in the regulation of the adaptability of GIB and LS to salt stress.

Warming and nitrogen deposition can affect the functions and structures of alpine meadow ecosystems on the Qinghai-Xizang Plateau. Ecological stoichiometry provides a framework to understand the biogeochemical cycling of nutrients between plant and soil. This study conducted a field experiment in an alpine meadow of Qinghai Province， to investigate the effects of different levels of warming and nitrogen deposition. The warming treatment included four levels： W0 （no warming）， W1 （air temperature increases 0.47 °C， soil temperature increases 0.61 °C）， W2 （air temperature increases 0.92 °C， soil temperature increases 1.09 °C）， W3 （air temperature increases 1.44 °C， soil temperature increases 1.95 °C）. Nitrogen application treatments included： N0 （no nitrogen application）， 16 kg N/（hm²·a）， and 32 kg N/（hm²·a）. The experiment assessed changes in carbon， nitrogen， and phosphorus contents in plant and soil， soil enzyme activity， and their stoichiometric ratios， as well as the relationship among these components. The results showed as follows： Warming significantly increased total nitrogen in the aboveground plant tissues， soil total nitrogen， soil organic carbon， the soil nitrogen phosphorus ratio， and the enzyme nitrogen phosphorus ratio. Simultaneously， it significantly decreased the carbon nitrogen ratio in aboveground plant biomass， and the carbon nitrogen and carbon phosphorus ratios of soil enzymes. Nitrogen deposition significantly increased total nitrogen in both aboveground and root tissues， soil organic carbon， soil total nitrogen， and the enzyme carbon nitrogen ratio. It significantly decreased the root carbon nitrogen ratio and enzyme nitrogen phosphorus ratio. The interaction between nitrogen deposition and warming significantly affected soil organic carbon content and the carbon nitrogen， carbon phosphorus， and nitrogen phosphorus ratios of soil enzymes. Analysis of stoichiometric homeostasis in plant tissues in responses to soil elements and enzyme activities revealed strict stoichiometric homeostasis in plant tissues under both warming and nitrogen deposition. Soil total nitrogen， soil carbon nitrogen ratio， and soil β-1， 4-xylosidase activity significantly influenced plant nutrient content and stoichiometry. In summary， short-term warming and nitrogen deposition significantly alter the stoichiometry of soil and enzyme systems in alpine meadows， which in turn influences the nutrient acquisition strategies of plants on the Qinghai-Xizang Plateau.

Smart prataculture represents a vital component of modern agriculture and serves as a key strategy for promoting sustainable agricultural development and advancing the initiative “Big Food View” in China. As global challenges such as climate change and land degradation intensify， traditional grassland management models are increasing unable to meet the requirements of modernization. The integration of artificial intelligence （AI） technologies presents unprecedented opportunities for the advancement of prataculture， greatly enhancing the efficiency， precision， and intelligence of grassland management. AI-driven smart prataculture employs cutting-edge technologies such as machine learning， deep learning， big data analytics， and the Internet of Things （loT）. Through comprehensive data collection and analysis， these technologies enable real-time monitoring， precise prediction， and adaptive management of grassland growth， resource allocation， and livestock production. While the application of AI demonstrates substantial potential in optimizing grassland productivity， ecological restoration， and livestock health monitoring， significant challenges remain in data collection， technological dissemination， infrastructure development， talent cultivation， economic feasibility， and policy support. In the future， continued innovation in AI technologies and the integration of interdisciplinary approaches are expected to accelerate the intelligent transformation of prataculture in China. This evolution will promote comprehensive intelligence， precision， and transparency across the entire industry chain， from production and ecological protection to resource utilization and market systems， thereby providing new insights for the sustainable development of smart agriculture.

In order to investigate the effects of different mowing stubble heights and fertilization on the dominant species and soil trace element contents in meadow grassland， this research focused on Hulunbeier meadow steppe. Trace element contents of the dominant species Leymus chinensis and the surface soil （0～10 cm） were determined under the following treatment combinations：six mowing stubble heights （3， 6， 9， 12， 15 cm， and no mowing） and two fertilization levels （no fertilization and fertilization）. The results showed that mowing significantly increased （P<0.05） the total soil manganese （Mn） content. Fertilization significantly reduced （P<0.05） iron （Fe）， copper （Cu）， zinc （Zn）， molybdenum （Mo） contents of L. chinensis， whereas total Mn and Zn contents， available Zn and Mo contents， and effective coefficients of Mn， Zn， and Mo in soil were increased （P<0.05）. The interaction of mowing and fertilization did not affect the contents of Fe， Mn， Cu， Zn， Mo and boron （B） significantly. The highest total soil Mn content of 435.4 mg/kg was observed with the 12 cm stubble height under no fertilization treatment. When fertilization was applied， the highest Fe （191.6 mg/kg）， Mn （35.5 mg/kg）， Zn （10.8 mg/kg）， and B （4228.3 mg/kg） contents in L. chinensis were recorded， at the 6 cm stubble height， while available contents of Fe （126.7 mg/kg）， Mn （94.5 mg/kg）， Cu （1.4 mg/kg） and Mo （1.3 mg/kg） in soil reached maximum values with the 12 cm stubble height. Fertilizer application with 12 cm stubble height increased the effective coefficients of soil Mn， Zn， Mo and B by 0.1， 0.2， 0.4 and 1.9×10^-4， respectively. Compared with the treatment without fertilization， fertilization at a stubble height of 12 cm increased the contents of Fe， Mn， Cu and B of L. chinensis. This research can provide a practical reference for the establishing sustainable mowing system in meadow steppe.

The response of grassland plants to grazing pressure and their subsequent growth dynamics are critical for maintaining ecosystem stability. As the primary interface for grazing interactions， leaf growth status is not only regulated by external environmental factors， but also significantly influenced by the metabolic activities of epiphytic microorganisms. This research investigated the responses of epiphytic microbial community characteristics of dominate species to grazing in temperate typical grasslands of northern China. High-throughput sequencing technology was applied to analyze the diversity and community composition of phyllosphere bacterial and fungal of Leymus chinensis， Stipa grandis， and Cleistogenes squarrosa. Results showed that：（1） Under both grazing and enclosure conditions， the epiphytic microbial communities of all three plant species were consistently dominated by bacterial phyla including Pseudomonadota， Bacillota， Bacteroidota， Actinobacteriota， and Acidobacteriota， along with fungal phyla Ascomycota and Basidiomycota. Notably， grazing disturbance significantly reduced the relative abundance of Proteobacteria in L. chinensis phyllosphere communities， creating ecological niches for colonization of other microbial taxa. Under grazing conditions， concurrently， a significant reduced in Filobasidium abundance within fungal communities of L. chinensis was observed， This change may reduce the risk of plant disease. （2） Under grazing conditions， the phyllosphere exhibited an enrichment of unique microbial taxa. Thermotogota was detected for the first time in bacterial communities of L. chinensis， while Kickxellomycota was identified as novel colonizer in fungal communities of C. squarrosa. These newly identified microbial taxa may significantly influence the adaptability and functional diversity of phyllosphere microenvironments. （3） The responses of functional classification in phyllosphere fungi to grazing and host specificity were significantly stronger. Under grazing conditions， relative abundance of pathogenic fungal decreased， whereas beneficial fungi increased， indicating that grazing may indirectly suppress pathogen proliferation by altering the phyllosphere microenvironment. In conclusion， effects of grazing directly alters phyllosphere microbial community structure by modifying host plant characteristics and their associated microenvironments， ultimately increasing microbial diversity and the proportion of beneficial microorganisms.

The production performance and nutritional value of alfalfa remain pivotal concerns in the alfalfa industry development.This study evaluated 36 alfalfa accessions （31 cultivated varieties and 5 wild germplasms） using Grey Correlation Analysis.The results revealed significant differences （P<0.05） in both agronomic performance and forage quality parameters among the 36 alfalfa accessions. Hay yield of alfalfa ranged from 5380.74 to 12663.31 kg/hm²， with the high-yielding accession M10 demonstrating the highest fresh forage yield （54457.13 kg/hm²）. Notably， the medium-yielding accession M7 exhibited superior nutritional profiles with 19.03% of crude protein， while M11 had the highest relative feed value of 152.76. Accessions were selected by comprehensive analysis of grey correlation as three utilization categories：nine as superior， 25 as moderate， and 2 as inferior. Furthermore， wild alfalfa germplasm M31 and M32 exhibited superior comprehensive evaluation scores， demonstrating significant breeding potential for cultivar development. This research provides reference for alfalfa cultivar introduction in Urumqi County and supplies outstanding germplasm resources for development and utilization of native alfalfa in Xinjiang.

In this research， effects of three light modes of LED red， blue， and green light spectrum at 23.328 mol/（m²·d） DLI （conventional light with 18 h/6 h， red∶blue∶green=280∶70∶10； continuous light with 24 h/0 h， red∶blue∶green=210∶52.5∶7.5； and alternating light with three light spectra： 24 h/0 h， red∶blue∶green=525∶15； red-green light∶blue light=435∶105； green and blue light∶red light=120∶420） on yield quality， physiological activity， and nitrogen metabolism were determined in an controlled environment plant factory with artificial light. The results demonstrated the adaptability of alfalfa to continuous light. Compared with conventional lighting， healthy morphology and maintained yield were observed in alfalfa under continuous lighting， along with increased soluble sugar and starch content. However， decreases occurred in photosynthetic pigment content， stomatal conductance， and Fv/Fm， without excessive accumulating of H₂O₂ and malondialdehyde. Further data showed that the alternation of red/blue-green light promoted leaf expansion， the alternation of red/green-blue light promoted stem elongation， and the alternation of green/blue-red light shortened the flowering time. In terms of nitrogen metabolism， nitrate nitrogen content was significantly reduced under continuous and green/blue-red light alternation， while ammonium nitrogen content was significantly increased under red/green-blue light alternation. Activity of nitrate reductase was significantly reduced under red/blue-green light alternation， while red/green-blue light alternation significantly reduced nitrite reductase activity. The activity of nitrogen metabolism enzymes was inhibited by continuous and alternating lighting， whereas the content of soluble protein， free amino acids， and crude protein in alfalfa were increased. In summary， continuous lighting and alternating lighting patterns are suitable for the production of alfalfa in plant factory with artificial light.

Plant rhizosheath is the sheath-like structure tightly adhering to the root surface. The unique physical， chemical， and microbiological characteristics of the rhizosheath contribute to vital environmental and biochemical functions including rhizosphere soil aggregation， formation of soil aggregates， enhanced water and nutrient uptake， promotion of microbial colonization， and drought stress resistance. This review provides comprehensive understanding for the research status about rhizosheath in formation and the function and objectively demonstrates current research hot spot. CiteSpace software and bibliometric methods were conducted to retrieve a total of 2812 publications related to rhizosheath from January 1， 2008， to April 30， 2023 in Web of Science （WOS） Core Collection and China National Knowledge Infrastructure （CNKI） database with key words “Rhizosheath”， “Root hair”，“Root exudate”，‘Root sheath’， ‘Root secretion’， and ‘Root hair’. This review illustrates biological， chemical， and physical interactions determining rhizosheath development and plant absorption of water and nutrient from perspectives of plant rhizosheath formation and function. The review aims to provide guidance for further research on molecular genetic mechanisms of rhizosheath development and the application on crop breeding.

To investigate the mitigation effect of externally applied γ-aminobutyric acid （GABA） on the growth of alfalfa seedlings under drought stress， this study explored five new drought-resistant alfalfa lines （P1， P2， P3， P4， and P5） and five drought-sensitive materials （15354， 7657， 7470， 7740， and 15578）. With normal water supply as the control （CK）， drought stress was simulated using the previously screened stress intensity （-1.6 MPa PEG-6000）. Under this drought stress treatment， exogenous GABA was applied at concentrations of 0， 5， 10， and 15 mmol/L （designated as T1， T2， T3， and T4， respectively） to analyze their effects on the physiological characteristics of alfalfa seedlings. Results showed that external GABA application significantly increased superoxide dismutase， peroxidase， catalase， leaf relative water content， and root activity in alfalfa under drought stress， while the content of proline， soluble sugar， soluble protein， malondialdehyde， hydrogen peroxide， and the production rate of superoxide anion were decreased. Membership function analysis revealed the optimal alleviation of GABA on drought-stressed alfalfa under the T3 treatment， with significantly stronger mitigation effect on sensitive genotypes compared with drought-resistant lines. The results provide a theoretical basis for the rational application of GABA in drought-tolerant cultivation of alfalfa.

Following the implementation of two cycles of the Grassland Subsidy and Reward Policy （GSRP）， optimizing its design and execution to simultaneously enhance herder livelihoods and restore steppe ecosystem services remains a critical challenge. This study investigated stocking rate responses among herders in China's desert steppe region， employing stratified random sampling across six pastoral townships combined with satellite remote sensing data. Structural equation modeling and statistical analysis were used to assess stocking rates under the GSRP framework. The results showed that the GSRP exerted the strongest influence on stocking rates relative to other factors. Stocking rates exhibited an exponential decline in response to increases in both the total subsidy amount and its proportion within household income； however， the rate of decline moderated beyond specific thresholds. Based on the fitting equation， the amount of grassland compensation （¥29296.93） and its income proportion （23.79%） were calculated with the stocking rate of 1 sheep unit/hm² as the reference value， and the herder groups were divided accordingly， the response characteristics of different herder groups to the grassland subsidy policy were analyzed. Results identified herder groups receiving subsidies below ¥29296.93 with a subsidy proportion below 23.79% as optimal responders， demonstrating rapid stocking rate reduction with increasing subsidies. Herder groups falling into either of the two intermediate categories （subsidy<¥29296.93 and proportion>23.79%； or subsidy>¥29296.93 and proportion<23.79%） were moderate responders， representing key targets for enhanced policy effectiveness. Herder groups falling into either of the two intermediate categories （subsidy<¥29296.93 and proportion>23.79%； or subsidy>¥29296.93 and proportion<23.79%） had limited response to the policy， it is the target groups to improve the effectiveness of the subsidy measures in the next step. However， the herder groups receiving subsidies exceeding ¥29296. 93 with a proportion above 23.79% had no obvious response to the policy. The next step should be to focus funding on groups that are more responsive to policy. Moving forward， GSRP optimization in desert steppe regions should elevate subsidy benchmarks， integrate household economic characteristics into policy design， and implement tailored strategies for distinct herder groups.

Shrub encroachment， which significantly alters structure and function of grassland ecosystems， is a critical ecological issue in China. To obtain a comprehensive and quantitative understanding of the research trends on shrub encroachment research in China， this study conducted a bibliometric analysis using CiteSpace and a meta-analysis based on published literatures on shrub encroachment in China since 1970s. Research on shrub encroachment in China had developed rapidly in recent years， with a primary focus on the drivers of shrub encroachment and its impacts on soil， vegetation， and biodiversity. Studies on shrub encroachment in China had been predominantly conducted in drylands and alpine regions. Major drivers of shrub encroachment included grazing management， climate change， habitat characteristics， and fire. Shrub encroachment was found to have a negative impact on soil quality but a positive effect on community composition， as well as the structure of vegetation and microbial communities in China. The primary management techniques for shrub encroachment included grazing exclusion， grazing management， physical removal， and prescribed burning. This study provides scientific insight into the drivers， impact， and future management strategies for shrub encroachment in Chinese grassland. In the future， it is necessary to strengthen large-scale dynamic assessments of shrub encroachment across diverse grassland types， and integrate remote sensing technology to enhance the scientificity and effectiveness of monitoring and management of encroached landscape in China.

The desert steppe is increasingly affected by severe degradation， and enclosure has been recognized as an effective method for restoring degraded grasslands. Therefore， understanding the effects of enclosure on plant species diversity and aboveground biomass in desert steppes is essential for grassland conservation. This study investigated the effects of different enclosure durations （3 years， 13 years， 18 years， and 20 years） on plant communitiy characteristics， species diversity， and aboveground biomass in the Siziwang Banner and Zhurihe grasslands. The results showed that aboveground biomass exhibited an increasing trend with extended enclosure duration. The important values of perennial grasses， such as Cleistogenes songorica and Stipa breviflora， gradually increased， whereas those of degradation indicator species， including Salsola collina， Convolvulus ammannii， and Neopallasia pectinata， progressively declined， or even disappeared. Vegetation height and canopy coverage increased as enclosure duration extended. In plots enclosed for 13 years， the response ratios of the dominance index， diversity index， richness index， and evenness index reached their peak values. Meanwhile， in plots enclosed for 18 years， aboveground biomass attained its maximum value. A positive correlation was observed between aboveground biomass and the response ratio of the diversity index. This study provides scientific evidence for the restoration of desert steppe ecosystems， demonstrating that enclosure measures effectively promote ecosystem recovery and enhance vegetation community structure.

In this research， effects of varying apple pomace to citrus pulp ratios on the volatile compounds were analyzed by headspace-gas chromatography-mass spectrometry to evaluate the odor composition of wheat straw mixed silage. Silage was fermented for 45 days using mixtures of citrus pulp and apple pomace at mass ratios （m/m） of 0∶4 （T0）， 1∶3 （T1）， 2∶2 （T2）， 3∶1 （T3）， and 4∶0 （T4）. The water content was adjusted to approximately 65% by adding wheat straw. The results showed that the ammonia nitrogen content of T2， T3 and T4 groups was less than 5%， and there was no significant difference in silage pH and lactic acid content. Compared with T0， the relative abundance of Lactobacillus （P<0.05） in T4 was significantly higher， while relative abundances of Enterobacter and Weissella （P<0.05） were lower. The contents of esters such as ethyl acetate and 2-methylbutyl acetate gradually increased with the increase in apple pomace mixing ratio， while the contents of terpenes such as D-limonene and α-acacia gradually decreased. The relative abundance of Enterobacter positively correlated with acetic acid， ammonia-nitrogen， and D-limonene contents （P<0.01）， and had negative correlation with lactic acid， ethyl acetate， and 2-methylbutyl acetate contents （P<0.01）. In summary， the 2∶2 mixture of apple pomace-citrus pulp improved fermentation quality and volatile compound profiles， and maximized citrus pulp utilization efficiency.

This study employed multivariate statistical methods， including analysis of variance （ANOVA）， principal component analysis （PCA）， correlation analysis， hierarchical cluster analysis， and membership function evaluation， to comprehensively analyze and evaluate five seed morphological traits of 329 wildrye （Agropyron cristatum） accessions conserved in the National Crop GeneBank. The objective was to establish a theoretical framework for the evaluation and innovative utilization of A. cristatum （L.） Gaertn germplasm resources. The results showed that among the five phenotypic traits examined， thousand-seed weight exhibited the highest genetic variation， with a genetic diversity index of 1.880 and a coefficient of variation of 24.56%. The average genetic diversity index for all five traits was 1.752， and the average coefficient of variation of 14.06%. PCA extracted three principal components， explaining 98.750% of the trait variation， with the first three main components contributing 65.555%， 26.162%， and 7.034% respectively， effectively preserving the core genetic information of seed traits. Correlation analysis demonstrated extremely significant positive correlations between seed length with the other four phenotypic traits （P<0.01）. Additionally， significant positive correlations were observed between seed width and both thousand-seed weight and single-seed area （P<0.01）， between thousand-seed weight and seed length-width ratio， as well as between seed length-width ratio and single-seed area. Hierarchical cluster analysis categorized the accessions into four groups： Group Ⅰ （284 accessions， moderate）， Group Ⅱ （41 accessions， small-grained）， and Groups Ⅲ and Ⅳ （two high-quality unique accessions each）. Comprehensive evaluation using the membership function identified B-288， B-243， B-233， and B-250 accessions with excellent performance in seed length， seed width， single-seed area， and thousand-seed weight. In contrast， B-152， B-143， B-128， B-149， B-141， and B-153 accessions exhibited relatively weak performance across multiple traits. In conclusion， seed length， single-seed area and thousand-seed weight were identified as the key morphological indicators contributing to the genetic diversity of A. cristatum germplasm.

Alfalfa （Medicago sativa） was introduced into China following Zhang Qian's diplomatic missions to the Western Region during the Han Dynasty. However， scholarly consensus regarding its precise provenance remains elusive. This study critically examines the origin of alfalfa in Han China by analyzing 43 historical texts from various periods that document its source， integrated with modern research findings. Our analysis reveals significant discrepancies in the proposed origins of Han-era alfalfa across ancient records and contemporary studies， coalescing into six primary hypotheses： （1） the Western Regions broadly； （2） Dayuan （Ferghana）； （3） Jibin （Kashmir region）； （4） Wusun； （5） Anxi （Parthia）； and （6） unspecified foreign lands. While Wang Yi of the Eastern Han Dynasty was the first scholar documented to explicitly associate alfalfa with the Western Regions， his era postdates those of Zhang Qian， Sima Qian， and Ban Gu. Consequently， the attribution solely to the broader Western Regions lacks substantive historiographical support. Alfalfa was firstly recorded in Shiji·Dayuan Liezhuan， and there were abundant similar records in the later historical books， that is， it is certain that the alfalfa in the Han Dynasty came from Dayuan and was brought from Dayuan by the Han envoys to the Western Regions. Although no extant texts explicitly record the introduction of alfalfa from Jibin to the Central Plains， the possibility cannot be entirely excluded following the initial introduction from Dayuan， as suggested by relevant accounts in the Hanshu （Book of Han）， Xiyu Zhuan （Account of the Western Regions）. The proposed origins from Wusun， Anxi， or other unspecified foreign lands lack convincing support from primary historical sources and warrant further validation.

Dof （DNA-binding with one finger） transcription factors are plant-specific regulators playing critical roles in plant response to environmental stresses. This study comprehensively identified MrDof gene family based on the genome-wide of Medicago ruthenica. We performed analyses including collinearity assessment， phylogenetic analysis， and chromosomal localization on the Dof family members. Furthermore， by integrating transcriptome data of M. ruthenica under drought stress and qRT-PCR validation， we explored the potential functions of these genes in drought stress responses. The results showed that a total of 33 MrDof genes were identified in M. ruthenica， and the number of amino acids encoded by these genes ranged from 157 to 492 aa. According to the evolutionary relationships among M. ruthenica， Medicago truncatula and Arabidopsis thaliana， these genes were classified into eight distinct groups （Group A， B1， B2， C1， C2.1， C2.2， C3， D1 and D2）. The 33 genes were unevenly distributed across nine chromosomes. Expression pattern analysis demonstrated that five genes （MrDof11， MrDof13， MrDof22， MrDof27， and MrDof30） were significantly induced by drought stress.

Nutrient enrichment is a key driver of plant diversity loss in grassland ecosystems. However， the specific pathways and mechanisms underlying species diversity reduction under different nutrient additions influence remain insufficiently understood. This study investigated the effects of nitrogen （N）， phosphorus （P）， and combined nitrogen and phosphorus （N+P） additions on alpine meadows located on the eastern edge of the Tibetan Plateau， using the natural community as a control. The main objective was to examine changes in species richness， biomass， and light transmission， and to elucidate the direct and indirect mechanisms contributing to species richness decline under these experimental treatments. The results showed as follows：（1） N was identified as the primary limiting nutrient for aboveground biomass. Both N and N+P additions significantly increased aboveground biomass （P<0.05）， primarily due to an increase in the biomass of grasses； （2） N and N+P additions significantly reduced species richness （P<0.05）， whereas P addition alone had no significant effect； （3） The mechanisms underlying the reduction in species richness under N and N+P treatments were consistent and involved both direct effects of nitrogen and indirect effects via increased aboveground biomass， which in turn reduced light availability.

Nitrogen deposition represents a critical driver of nitrous oxide （N₂O） emissions in global terrestrial ecosystems， with profound implications for climate change prediction. Although numerous studies have investigated soil N₂O emissions patterns in response to nitrogen addition， controversies persist regarding the regulatory mechanisms and driving factors. Through a meta-analysis intergrading the 87 global studies， we demonstrate that nitrogen addition significantly enhances soil N₂O emissions. This effect is particularly pronounced under high nitrogen application rate （>200 kg/hm² year）， in low-precipitation regions （≤400 mm annual rainfall）， and with short-term and moderate-term nitrogen application （≤3 years）. Our analysis identified nitrogen input level， mean annual precipitation， and ecosystem type as the dominant factors controlling global N₂O emissions， providing a scientific foundation for developing targeted emission mitigation strategies.

This study investigated the effects of various fertilization treatments on natural mowing grassland in the Altay Mountains， combining field investigations with indoor laboratory analyses. The experiment included four fertilization measures：no fertilization （control）， compound fertilizer， organic fertilizer and bio-bacterial fertilizer. The primary objective was to assess these treatments on grassland plant community characteristics， soil nutrients， and soil microorganisms. The results showed as follows：（1） Compound fertilizer application significantly increased aboveground biomass （P<0.05）， but decreased underground biomass in the 0~10 cm soil layer. Bio-bacterial and organic fertilizers increased species diversity， while compound fertilizer reduced it. Notably， the Shannon-Wiener index was significantly higher under bio-bacterial fertilizer than under compound fertilizer （P<0.05）； （2） Fertilization significantly lowered soil pH and increased soil organic matter content. Organic fertilizer significantly increased available nitrogen content （P<0.05）， while compound fertilizer significantly raised available phosphorus and available potassium concentrations （P<0.05）； （3） Fertilization significantly increased the number of bacterial operational taxonomic units （OTUs） and decreased fungal OTUs （P<0.05）， indicating shifts in microbial community structure and enhanced microbial diversity. A comprehensive evaluation using a membership function approach indicated that compound fertilizer had the most substantial effect in improving degraded natural meadows. These findings provide a scientific basis for enhancing the productivity and soil fertility of natural meadows through appropriate fertilization strategies.

Grassland restoration is a critical pathway toward achieving sustainable utilization and high-quality development goals for degraded ecosystems. While scientific evaluation of restoration outcomes provides essential evidence for optimizing rehabilitation strategies， current methodologies predominantly focus on pre- and post-restoration changes in individual or limited indicators （e.g.， biomass， vegetation coverage）， with insufficient attention to comprehensive multi-indicator assessments. To address this issue， this study used factor analysis to comprehensively evaluate eight restoration approaches and nine ecological restoration effect assessment indicators for degraded grasslands in Chen Barag Banner， Inner Mongolia， aiming to identify representative community assessment indicators and suitable restoration approaches. The findings demonstrated that： （1） Three critical indicators-vegetation coverage， aboveground biomass， and community species richness-were identified as representative metrics for restoration evaluation. （2） The integrated approach combining fencing with root pruning， fertilization， and sustained management practices demonstrated superior restoration effectiveness. Our comprehensive quantitative assessment methodology exhibited both scientific rigor and practical applicability. These findings provide an evidence-based framework for evaluating and managing grassland restoration initiatives in Inner Mongolia's degraded steppes and comparable ecoregions.

In order to investigate the root-specific genes regulating root growth of alfalfa （Medicago sativa），transcriptome sequencing was performed to analyze differentially expressed genes （DEGs） and their functions between the aerial parts （stems and leaves） and root system of alfalfa cultivar Zhongmu No. 1. The results showed that compared to aerial parts，a total of 15258 DEGs were identified in root system，including 5095 up-regulated and 10163 down-regulated. The GO functional annotation demonstrated significant enrichment of these DEGs in cellular process，metabolic regulation，and biocatalytic activities. KEGG pathway enrichment analysis showed significant enrichment of these DEGs in pathways related to porphyrins and chlorophyll metabolism，photosynthesis-antenna protein synthesis，and carbon fixation in photosynthetic organisms. Six candidate up-regulated genes exhibiting significant differential expression were selected for real-time quantitative PCR validation. The results indicated high concordance between their expression patterns and transcriptome sequencing data.

This study investigated the effects of phosphorus application depth and level on alfalfa biomass and the stoichiometric characteristics of carbon （C）， nitrogen （N）， and phosphorus （P） in different alfalfa organs within the Horqin Sandy Land. By measuring alfalfa biomass and the C， N， and P content in each organ under varying phosphorus application regimes， this research aimed to provide a theoretical basis for optimizing alfalfa yields in this region. The results showed that alfalfa aboveground biomass reached its maximum under the S15P320 treatment， with a peak value of 537.00 g/m². The highest C content was observed in stems， leaves， and roots under the S5P240， S10P320， and S10P160 treatments， respectively. The highest N content was recorded under the S5P160， S20P160， and S10P320 treatments， while P content peaked under the S5P240， S10P320， and S10P320 treatments. Correlation analysis revealed a significant negative correlation between N content and the C∶N ratio， and a significant positive correlation between N content and the N∶P ratio in stems， a significant negative correlation between P content and the stem C∶P ratio， a significant positive correlation between leaf N content and the leaf N∶P ratio， and a significant negative correlation between leaf N content and the leaf C∶N ratio， and a significant negative correlation between leaf P content and the leaf C∶P and N∶P ratios. Membership function analysis indicated that P addition in the S10P320 treatment had a significant positive effect on both total biomass and nutrient uptake in alfalfa.

Soil fauna is an important part of the terrestrial ecosystem and serves as a critical biological indicator for the maintenance of the grassland ecosystem function and stability. Global climate change combined with diverse anthropogenic disturbances， have induced substantial changes of soil faunal community structure and biodiversity， and further affected soil quality and soil health. This review systematically analyzed development and current status of soil fauna in Chinese grassland ecosystem the responses of soil fauna in different grassland types to simulated warming， nitrogen addition， precipitation change and anthropogenic disturbance （grazing， mowing， enclosure， reclamation and mining） Based on the review， three research directions for further research are proposed： to strengthen the interdisciplinary research of soil fauna， to establish long-term monitoring network across spatial gradients to assess effects of climate change on soil faunal community characteristics， and to illustrate the structural and functional stability of soil faunal community in grassland ecosystem.

Previous studies have extensively investigated the nature of collective action problems and the roles of actor attribute in the formation of collaborative governance networks of natural resource，however，due to the difficulty of measurement，there is often limited quantitative testing of the impact of local background factors. As a rational person embedded in social relations，the development of collaborative partnership of herdsmen is often affected by the existing local formal and informal social network. This study takes Dongtan village，Menyuan county，Qinghai province as a case，and adopts the whole-village investigation method to respectively construct the formal and informal social networks among herders and the collaborative governance network of grassland resources among herders. The exponential random graph model is used to empirically test the driving effect of formal and informal social networks on the formation of the collaborative network. The results show that： （1） Collaborative networks present a distinct transfer triangle configuration，but there was no tendency of relationship centralization；（2） Informal social networks formed based on emotional relationships had a significant positive promoting effect on the formation of collaborative networks. Emotional bonds facilitated the establishment of long-term mutually beneficial and trusting relationships，reduced transaction costs and risks，and were conducive to the development of collaborative relationships among herders. Although the formal rules can effectively avoid the problem of unfair distribution of resources by imposing constrains on power and factions，the formal social network based on the organizations have not had a significant impact on the formation of pastoral collaborative networks. To strengthen the effectiveness of collaborative governance of grassland resources，it is necessary to leverage the role the key leaders in the informal social network to activate the formal social network，facilitate the establishment of more collaborative organizations similar to cooperatives，and provide new ideas，information and technologies for the informal social network through the formal social network.

Grazing can alter the structure and function of grassland ecosystems. Currently， research on the impact of grazing on soil bacterial communities primarily focuses on the effect of grazing intensity on surface soil. However， the effects of grazing intensity on bacterial community structure in different soil layers remain unexplored. This study aimed to provide a theoretical basis for the protection and sustainable use of desert steppe ecosystems by examining the impact of grazing intensity on soil bacterial communities at various soil depths. High-throughput sequencing was used to examine the diversity and composition of soil bacterial communities at different depths under five grazing intensities： no grazing （CK）， light grazing （LG）， moderate grazing （MG）， heavy grazing （HG）， and extremely heavy grazing （OG） in the desert steppe of Inner Mongolia. The results showed as follows： （1） Compared to CK， the LG treatment significantly increased the diversity of the soil bacterial community in the 0-20 cm soil layer. （2） At the phylum and genus levels， compared to CK， the relative abundance of Actinobacteriota and Rubrobacter significantly decreased in the 0-20 cm soil layer under all grazing intensities. Under LG treatment， the relative abundance of Proteobacteria significantly increased. In the 20-40 cm soil layer， the relative abundance of Acidobacteriota and the RB41 significantly increased under MG treatment， while the relative abundance of Rubrobacter significantly decreased under OG treatment. （3） Redundancy analysis （RDA） revealed that dissolved organic carbon， total nitrogen， water content， ammonium nitrogen， nitrate nitrogen， and pH were the main environmental factors influencing changes in soil bacterial α-diversity. Correlation analysis between soil physical and chemical properties and the relative abundance of soil bacteria indicated that bacteria abundance in different groups was most strongly associated with ammonium nitrogen， nitrate nitrogen， water content， and organic matter. This study highlighted the effect of grazing on the composition of soil bacterial communities in the Inner Mongolia desert steppe by altering soil physical and chemical properties. The findings have significant implications for the sustainable management of desert steppe ecosystems in Inner Mongolia.

In order to explore the effects of drought stress on agronomic traits of different alfalfa varieties （strains）， 12 alfalfa varieties （strains） were used as materials in this study， pot experiments were carried out in greenhouse and two treatments of drought stress and rewatering were conducted at seedling stage， the agronomic traits （plant height， aboveground fresh and dry weight， root length， root fresh and dry weight， root shoot ratio， stem diameter， root diameter， branch number） of alfalfa materials after treatment were determined， and through the comprehensive drought resistance coefficient， principal component comprehensive evaluation， grey correlation degree and drought resistance index for comprehensive evaluation of drought resistance ability. The results showed that the new strain 1 had the highest drought resistance coefficient in aboveground fresh weight， aboveground dry weight， plant height， root length and branch number， the drought resistance coefficient of stem diameter of new strain 2， the drought resistance coefficient of root diameter of Gannong No.7 and drought resistance coefficient of root fresh weight and root shoot ratio of Zhongtian No.3 were the highest， the drought resistance coefficient of aboveground fresh weight，aboveground dry weight， root fresh weight， root dry weight， plant height， root length and branch number of Zhongmu No.3 was the lowest， the drought resistance coefficient of stem diameter in Gannong No.3 and drought resistance coefficient of root shoot ratio in Zhongtian No.2 were the smallest. The comprehensive drought resistance coefficient， principal component comprehensive evaluation， grey correlation degree and cluster analysis showed that the new strain 1， Zhongtian No.3 and Zhongmu No.1 had strong drought resistance. The drought-resistant germplasms identified by the Drought Resistance Index （DRI） method were new strain 1， Zhongtian No.3， new strain 3， Zhongmu No.1， and Gannong No.7， all of which displayed DRIs greater than 1. Comprehensive evaluation across multiple methods revealed that new strain 1， Zhongtian No.3， and Zhongmu No.1 possessed the strongest drought resistance.

Grazing is a primary utilization of grassland ecosystems， where livestock behaviors， specifically feeding， trampling， and excrement deposition， directly or indirectly alter soil physicochemical and biological properties. These alternations， in turn， differentially affect biogeochemical processes within the grassland ecosystem. However， the mechanisms by which these behaviors influence soil greenhouse gas （GHG） emissions remain poorly understood. To address this knowledge gap， this study systematically explored the emission mechanism and key influencing factors of carbon dioxide （CO₂）， methane （CH₄）， and nitrous oxide （N₂O） in grassland soil by analyzing the interactions between major grazing behaviors and soil environmental conditions. The results showed that feeding behavior can alter vegetation biomass and regulate vegetation community structure， thereby modifying exogenous carbon inputs to influencing soil CO₂ emissions. Trampling behavior impacts soil physical structure and microenvironmental conditions， which in turn affect soil aeration and microbial activity， leading to variable effects on soil respiration and associated CH₄ and CO₂ emissions. These effects are closely dependent on grassland type and trampling intensity. In contrast， dung and urine deposition increase nitrogen input to the soil and enhance N₂O emissions， primarily by altering soil chemical properties and microbial dynamics. The characteristics of the excreta， grassland type， and environmental conditions all play important roles in regulating nutrient availability and GHG emission in pastoral systems. These findings elucidate the distinct processes and potential mechanisms through which livestock behaviors affect soil GHG emissions in grassland and provide a theoretical basis for optimizing grazing management to mitigate emissions in pastoral ecosystems.

While the beneficial effects of silicon addition on Poaceae species have been widely reported， its mitigating effects and mechanisms of phosphorus deficiency in legumes remain unclear. In this study， a pot experiment was designed to investigate the effects of silicon application on alfalfa （Medicago sativa L.） under phosphorus limitation. Two nutrient conditions （nutrient balance and phosphorus limitation） and three concentrations of potassium silicate （0， 1， and 2 mmol/L） were applied to determine the effects of silicon addition on the growth characteristics， photosynthetic parameters， and nitrogen and phosphorus stoichiometric traits of the alfalfa under phosphorus limitation. The results showed that alfalfa biomass， plant height， photosynthetic rate， stomatal conductance， transpiration rate， photosynthetic water use efficiency， and shoot phosphorus content were significantly reduced by phosphorus limitation， whereas the shoot N∶P ratio increased particularly when no silicon was added. Silicon addition significantly increased biomass， plant height， photosynthetic rate， stomatal conductance， transpiration rate， and shoot phosphorus content of alfalfa under phosphorus limitation， while the addition under nutrient-balanced condition reduced stomatal conductance without affecting other parameters. Correlation analysis further revealed that under phosphorus-limited conditions， shoot silicon content was positively correlated with shoot phosphorus content and negatively correlated with the N∶P ratio. However， these correlations were not observed under nutrient-balanced conditions. Therefore， phosphorus limitation of alfalfa can be mitigated by silicon addition. Results demonstrated the associated mechanisms driving internal nutrient homeostasis from a stoichiometric perspective， and provided guidance and theoretical basis for the utilization of silicon in alfalfa cultivation under phosphorus deficiency.

In order to explore the effects of litter on the plant community characteristics and functional groups of desert steppe， this research focused on Stipa breviflora desert steppe in Inner Mongolia. A field control litter experiment （including no addition （CK）， adding 83.3 g/m² litter， and adding 166.6 g/m²） was conducted on degraded steppe under overgrazing for more than a decade. The results showed that the addition of litter improved community height， coverage， density and aboveground biomass under the adding 83.3 g/m² litter treatment， and the community height， coverage and aboveground biomass increased significantly by 2 cm， 3% and 9 g/m²， respectively. Plant community indices such as Simpson dominance index， Shannon-Wiene diversity index， Pielou evenness index and Margalef richness index were also increased significantly. The addition of litter enhanced the competition of perennial bunch grasses between perennial rhizome grasses and perennial forbs. Plants adapted to the environmental changes by altering the occupancy ratio of the functional groups. The addition of 83.3 g/m² litter had a more significant effect on plant community of the desert steppe. In conclusion， the input of appropriate amount of litter can help the recovery of degraded grassland by influencing the diversity of the community and the relationship between functional groups to promote the positive growth of grassland.

With the rapid climate change， the occurrence of compound dry-heat events has increased， leading to significant impacts on plant growth and ecosystem. Therefore， assessing the severity of compound dry-heat events and its impacts on vegetation growth are crucial for understanding the hazards of extreme climate and for developing effective mitigation and adaptation strategies. In this study， the Copula function was used to propose the standardized compound dry-heat events index （SCDHI） based on the cumulative joint probability of the standardized precipitation index （SPI） and the standardized temperature index （STI）. Evolution of the compound dry-heat events and corresponding vegetation responses in Xilin river basin were investigated based on the analysis of drought and high temperature dynamics during rapid growth stages （June to August） from 1982 to 2020. The results showed that the Frank-Copula was the most appropriate distribution function for combining SPI and STI. The SCDHI was well-fitted for quantifying the dependency of drought and high temperatures when displaying multi-scale spatiotemporal comparability and clear statistical significances. Changes of the drought conditions in the basin maintained basically stationary， while the high temperature events showed a significant upward trend. The climate of the basin generally tended to be warming and drying， with a slight aggravation of compound dry-heat events in July and August. The cooccurrence return period of the dry-heat events defined as SPI<-1.0 and STI>1.0 was about 10 years. Moreover， the sensitivity of vegetation to extreme climate conditions was closely related to the growth stage. Grassland vegetation had higher resistance to climate change in stable growth stage.

This research aims to investigate the effects of variations in precipitation on the ecological stoichiometry of soil organic carbon （SOC）， total nitrogen （TN）， and total phosphorus （TP） in desert steppes and to reveal the response of C， N， and P and their ecological stoichiometry to precipitation gradients in desert steppe ecosystems. The experiment was conducted in temperate desert steppe on the southern edge of Mu Us Desert， Yanchi County， Ningxia Hui Autonomous Region. Five precipitation levels， 33%， 66%， 100%， 133%， and 166% of natural precipitation （G1， G2， G3， G4， G5）， were simulated by rainout shelters and manual water replenishment. Variation patterns of SOC， TN， TP contents across soil layers （0-10 cm，10-20 cm， and 20-30 cm） were analyzed under different precipitation levels. The results indicate that： （1） When precipitation increased （G4）， the SOC， TN， and TP contents， and soil C∶P and N∶P ratios in 10-20 cm and 20-30 cm soils were significantly lower than in 0-10 cm soils （P<0.05）. However， the TP content did not respond significantly to precipitation changes. （2） With the increasing of soil layer depth， the correlation between the contents and ratios of SOC， TN， and TP within soil followed the order of 20-30 cm>10-20 cm>0-10 cm； （3） The variation in the SOC， TN， and TP contents was the highest in the 20-30 cm layer， followed by the 10-20 cm， and was the lowest in 0-10 cm. The variation of soil TP content was the least for all the three soil layers. In conclusion， precipitation changes have a significant impact on the ecological stoichiometry of soil carbon， nitrogen， and phosphorus， and the variation of carbon， nitrogen， and phosphorus in deep soil is greater. Deep soil （20-30 cm） is more responsive to precipitation changes than surface soil （0-20 cm）， indicating that the ecological stoichiometry of desert steppe soils is more sensitive to precipitation in deeper layers.

The design of the rules transfer of grassland contracted management rights aims to maximize the benefits of limited land while also protecting the herdsmen's mission. However， in practice， there are many problems in the application of this rule. By studying the grassland contract cases in recent years， this paper summarizes the types of contracts that violate the mandatory provisions of the Grassland Law， including subject violations， content violations， procedural violations， and object violation， in the judicial practice of our country， there are some problems in the determination of the violation of mandatory provisions in the transfer contract of grassland contractual management right， such as an excessively high proportion of invalid contract determinations and inconsistent interpretations of the same legal norms， we should measure the ecological interests and contractual interests of grassland protection in an all-round way by means of interest measurement， ensure the appropriateness of determining the invalidity of contracts under the guidance of the principle of proportionality， and ensure the stability of the market and the security of transactions with the goal of trust interests. Therefore， it is necessary to reshape the effectiveness of contracts that violate the mandatory provisions of the Grassland Law. By reducing the qualifications of grassland contracting entities， reducing the invalid identification of grassland contract management rights transfer contracts， and optimizing the procedural rules of grassland contract management rights transfer contracts， we can achieve sustainable use of grassland resources and protect the rights and interests of herdsmen.

Epigenetics plays a pivotal role in the adaptation to fluctuating external environmental conditions. Abiotic stresses alter the epigenetic modification status of plants， which in turn regulate stress responses of plants. This study presented a comprehensive analysis of the morphological， physiological， and epigenetic dynamics in Medicago truncatula when subjected to salinity， drought， heat， and cold stresses. The interplay between epigenetic modifications with the morphological and physiological traits of Medicago truncatula under stress conditions were explored by correlation analysis. Results revealed that these abiotic stresses significantly inhibited the growth and physiological status of Medicago truncatula， in which reduction in leaf area （except under low temperature）， the weight of leaves （dry）， stems （dry） and above ground fresh （dry） was significantly reduced relative water content， and total chlorophyll content， and increase in relative electrical conductivity， soluble sugar， and total antioxidant capacity were observed （P<0.05）. Meanwhile， epigenetics was involved in the regulatory processes of Medicago truncatula under stress conditions， though the regulatory mechanisms among various epigenetic modifications were different. Under all four stress conditions， DNA methylation levels significantly increased， while acetylated histone content reduced. Methylated histone content increased only under salt stress， with decreases under the other three stresses. Histones ubiquitinylation was risen under salt and low-temperature stress， whereas high-temperature stress reduced this content （P<0.05）， also with no significant changes under drought stress. Correlation analysis further indicated a positive correlation between N-6-methyladenosine content and acetylated histones with leaf morphological indicators， such as leaf fresh weight， leaf dry weight， and leaf area， except in acetylated histones content with leaf area. Conversely， this two parameters were negatively correlated with physiological indicators such as relative electrical conductivity， soluble sugars， and total antioxidant capacity， except between N-6-methyladenosine content with relative electrical conductivity. This research provides preliminary evidence in adaptive characteristics of Medicago truncatula in response to various abiotic stresses from an epigenetic perspective and lays a foundational theoretical framework for the epigenetic molecular breeding of legume forage grasses to enhance stress tolerance.

This study aimed to reveal the effects of three carbendazim concentrations on physiological characteristics and bacterial community of silage maize in three maturity stages （big trumpet stage，milk stage，and dough stage）. Results showed that the net photosynthetic and transpiration rate at the big trumpet stage and dough stage decreased by 9.50 µmol/（m²·s） and 15.2 µmol/（m²·s），1.75 mmol/（m²·s） and 2.59 mmol/（m²·s），respectively （P<0.05） compared with milk stage. Compared with at the big trumpet stage and dough stage，the moisture retention capacity at the milk stage increased by 24.50% and 13.20%，respectively （P<0.05）. The numbers of aerobic bacteria，Escherichia coli，and lactic acid bacteria at the milk stage and dough stage were significantly reduced （P<0.05） compared with the big trumpet stage. The concentration of carbendazim had no significant impact on the physiological characteristics or bacterial numbers of silage maize. At the genus level，the four bacteria with the highest relative abundance were Sphingomonas，Massilia，Rhodococcus，and Frigoribacterium. Different concentrations of carbendazim significantly affected the relative abundances of Pseudonocardia，Clostridium_sensu_stricto_1，Friedmanniella，unclassified_o_Micrococcales，Luteimonas，Steroidobacter，and Acinetobacter （P<0.05）. Considering the utilization of maize silage and the need to prevent the proliferation of drug-resistant bacteria，this study recommends applying low concentration carbendazim on silage maize.

This study aimed to explore the impacts of salt stress on the photosynthetic characteristics and sugar metabolism of Astragalus cicer seedlings. A. cicer cultivar ‘Gan Green No. 2’ was treated by 120 mmol/L NaCl solution as salt stress simulation. Sampling was conducted at 0， 1， 3， 5， 7， 14， and 21 days after stress applied for relevant indices measurement. The results indicated that salt stress induced stomatal closure in the leaves of A. cicer seedlings resulting in reduced stomatal conductance reduction and impairment of the photosynthetic system. Simultaneously， the chlorophyll content， net photosynthesis rate， transpiration rate， actual photochemical efficiency， apparent photosynthetic electron transport rate （ETR）， and photochemical quenching coefficient were significantly decreased. However， the contents of sucrose， fructose， and glucose exhibited trends of increasing initially followed by declining. Moreover， the intercellular CO₂ concentration， non-photochemical quenching coefficient （NPQ）， starch content， sucrose synthase （SS） activity， and activities of soluble acid invertase （SAI） and neutral invertase （NI） increased and eventually stabilized with treatment time prolonged. In contrast， the sucrose phosphate synthase activity （SPS） gradually exhibited a decreasing trend. Correlation analysis demonstrated that soluble sugars content were closely related to photosynthetic parameters， suggesting that sugars may play a crucial role in regulating of photosynthesis and plant light use efficiency. Starch content was positively correlated with NPQ， indicating that starch may be involved in regulating photoprotection and energy dissipation. In conclusion， salt stress tolerance of A. cicer seedlings can be enhanced by regulating sugar metabolism-related enzyme activities and photosynthetic system， leading to increased soluble sugar and NPQ levels. The findings of this study provide valuable insights into the growth and physiological mechanisms of A. cicer in saline-alkaline soils.

To explore the effects of different grazing intensities on soil microbial biomass in alpine meadow，this study investigated the variation characteristics in soil microbial biomass and interactions between soil physicochemical properties and microbial parameters including biomass，microbial quotient，and stoichiometric ratios under no grazing （CK），light grazing （LG），moderate grazing （MG），heavy grazing （HG），and extreme grazing （EG） conditions in the alpine meadow of Tianzhu Zangzu Autonomous County on the northeastern edge of the Qinghai-Tibet Plateau. The results showed that both microbial biomass carbon （MBC） and phosphorus （MBP） reached the maximum levels under LG，which were significantly higher compared with EG condition （P<0.05）. Soil microbial biomass nitrogen （MBN） was highest under HG，followed by MG，while MBN was significantly lower under EG compared with HG （P<0.05）. Soil microbial quotient carbon （qMBC），microbial quotient phosphorus （qMBP） and the MBC∶MBN ratio were all highest under LG，whereas microbial quotient nitrogen （qMBN），MBC∶MBP ratio，and MBN∶MBP ratio were highest under MG. Soil bulk density emerged as the predominant factor influencing microbial biomass，microbial quotients，and their stoichiometric ratios. These findings indicate that both light and moderate grazing intensities benefit the accumulation of microbial biomass and promote efficient utilization and transformation of soil nutrient in alpine meadows. In contrast，extreme grazing leads to soil fertility decreasing and a reduction of microbial biomass. A win-win scenario of ecology sustainability and economic benefits will be achieved when apporiate grazing intensities adopted.