Vetch （Vicia） forage species possess significant forage value and ecological functions. In the context of global climate change， abiotic stresses such as low temperature， drought， salinity， and heavy metal contamination pose severe challenges to their growth， development， yield formation， and safe utilization. Considerable research progresses on the stress resistance physiology and molecular regulatory mechanisms of vetch forage have been reported in recent years. Notable advances have been made in understanding their adaptive responses to stresses through osmotic regulation， antioxidant defense， hormonal signaling， ion homeostasis， and related gene regulatory networks. However， most existing studies have focused on single stress conditions and are limited to a few species such as common vetch （Vicia sativa）. Knowledge regarding the responses of vetch plants to combined stresses， the genetic basis of stress-resistant traits， and systematic regulatory mechanisms remains insufficient. This review systematically summarized research progress on vetch forage under abiotic stresses， including low temperature， drought， salinity， and heavy metal stress. It highlighted key physiological adaptive features and molecular regulatory patterns， and discussed future directions for stress resistance improvement and molecular breeding in light of emerging research trends such as multi-omics integration， combined stress analysis， and rhizosphere microbial interactions. The aim is to provides insights for the development of stress-resistant germplasm and the efficient utilization of vetch forage resources.

Calcium-dependent protein kinases （CDPK/CPK） are a class of Ca²⁺-sensitive Ser/Thr protein kinases， which play important roles in plant growth and development， as well as in response to abiotic stresses. CDPKs could autophosphorylate or phosphorylate metabolic enzymes， ion channels， transcription factors， and membrane transporters， forming complex signaling networks to respond to abiotic stresses， such as salinity， drought， and low temperature. Meanwhile， CDPKs also participate in plant hormone signaling pathways such as abscisic acid and salicylic acid to modulate plant growth and development. This study reviews the research achievements concerning the structure， classification， regulatory mechanisms， roles in abiotic stress responses， and breeding applications of plant CDPKs.This paper also proposes future application prospects for CDPKs in the field of breeding， aiming to provide genetic resources and a theoretical basis for the genetic improvement of crop stress resistance and biological breeding.

Field phenotyping is fundamental to crop variety evaluation. However， traditional data acquisition methods are often destructive， costly， and subjective， and conventional 3D reconstruction techniques struggle to capture fine plant structures. To address these challenges， this study proposed a high-throughput phenotyping method for individual oat plants based on smartphone video acquisition and 3D Gaussian Splatting （3DGS） technology. The experiment utilized 187 oat plants at the milky stage as tested materials. Multi-view video data captured by smartphones were used to generate 3DGS point cloud models， from which canopy structural parameters—including projected area， maximum canopy width， and average canopy width-were extracted. Canopy volume was calculated using both Convex Hull and Voxelization （voxel size 0.01 m and 0.005 m） methods. Furthermore， biomass （fresh and dry weight） prediction models based on canopy volume were constructed using Random Forest （RF） and Support Vector Machine （SVM） algorithms. The results showed that： （1） 3DGS technology achieved high-fidelity reconstruction of the complex morphology of oats， effectively resolving issues related to slender leaves， thin stems， and severe self-occlusion， thereby demonstrating significant advantages over traditional reconstruction methods in restoring intricate structural forms； （2） Biomass estimation models based on 3DGS point cloud volume were reliable， with dry weight prediction accuracy （Accuracy≈0.88） generally superior to that of fresh weight； notably， high-resolution voxelization （voxel size 0.005 m） demonstrated a slight advantage in accurately describing the physical canopy structure. The workflow established in this study-“Smartphone Video Acquisition-3DGS Modeling-Phenotypic Parameter Extraction”-offered a low-cost， high-precision， and non-destructive solution， providing effective technical support for high-throughput phenotypic analysis of fields.

Establishing an efficient genome editing system in forage oats has long been a crucial approach for oat germplasm innovation. However， due to the hexaploid nature of forage oats， genetic transformation efficiency is relatively low， posing significant challenges in creating new germplasms using genome editing technology. Here， the genetic transformation efficiency of forage oats was significantly improved through the exogenous addition of small peptides. Simultaneously， genome editing efficiency was enhanced by employing T5E fusion proteins， leading to the development of an independent intellectual property genome editing technology system for forage oats with an editing efficiency of 20%. Additionally， a multi-genome editing system for forage oats was established with an editing efficiency of 23%， and a single base editing system for forage oats was developed with an editing efficiency of 21.4%. The establishment of highly efficient genetic transformation and genome editing systems for oats holds significant importance for gene function research and germplasm innovation in forage oats.

To elucidate the potential roles of the quinoa PHD-finger gene family in development and stress adaptation， this study was conducted based on the reference genome of quinoa （Chenopodium quinoa Willd.） and transcriptomic datasets from multiple sources. Genome-wide identification， chromosomal localization， phylogenetic analysis， gene structure characterization， conserved motif analysis， cis-acting element prediction， duplication event analysis， and expression profiling were performed， followed by validation using qRT-PCR. A total of 69 CqPHD-finger members were identified and found to be unevenly distributed across 18 chromosomes. The expansion of this gene family was mainly driven by segmental duplication. Phylogenetic analysis classified these members into 13 subgroups， and their promoters were enriched in cis-acting elements associated with light signaling， hormone responses， and stress responses. Members of group 9 clustered closely with proteins related to abiotic stress responses， whereas members of group 10 showed a close phylogenetic relationship with proteins involved in tapetum and pollen development. Expression analysis revealed that this gene family exhibited tissue-specific expression patterns in meristems， floral organs， and mature seeds， and showed pronounced responses to high temperature， drought， and long-day conditions. qRT-PCR analysis demonstrated that CqPHD-finger29， CqPHD-finger66， CqPHD-finger30， and CqPHD-finger23 exhibited significant photoperiod responsiveness， suggesting that they might participate in the regulation of photoperiod-dependent flowering in quinoa. This study provides a theoretical basis for further elucidating the functions of the PHD-finger gene family in quinoa reproductive development， stress responses， and photoperiodic regulation.

Leymus chinensis is the main dominant species in the eastern Eurasian steppe， with significant ecological and production values. However， its low seed yield severely restricts its practical application. To identify the associated loci for the seed yield traits of L. chinensis and to discover key molecular markers， this study used 300 diverse accessions of L. chinensis as materials， measured five yield traits including spikelet number per spike， floret number per spikelet， total number of florets， seed number per spikelet and seed setting rate， and conducted a genome-wide association analysis （GWAS） using a mixed linear model. The results showed that seed number per spikelet exhibited the highest coefficient of variation （CV=0.52）， indicating substantial potential for genetic improvement. The seed setting rate was regulated by an independent genetic mechanism and was the key limiting factor for seed yield. GWAS analysis combined with gene functional annotation identified 120 key single nucleotide polymorphisms （SNPs） and identified EZ1 and multiple MADS-box and WRKY transcription factors as key candidate genes regulating seed yield. Based on 14 SNPs significantly associated with seed setting rate， 8 elite alleles were obtained. Notably， the CT genotype at the Lc5Ns_97563471 locus exhibited a high mean seed setting rate of 66.6%. This study revealed the genetic characteristics of L. chinensis seed yield being regulated by multiple genes， and the identified candidate genes and elite SNP loci can serve as direct targets for molecular marker-assisted breeding.

The symbiont formed by legumes and rhizobia plays a crucial role in the nitrogen cycle， and root exudates significantly affect the nodulation process. The pretreatment and detection methods for metabolites of rhizobia from Lespedeza daurica have not been systematically optimized. In this study， the extraction efficiency of rhizobial metabolites was improved by optimizing pretreatment conditions， including ultrasonic temperature （A）， ultrasonic time （B）， derivatization temperature （C）， and derivatization time （D）. Single-factor experiments were used to determine the ranges of detection conditions， followed by a four-factor， three-level Box-Behnken response surface methodology （ultrasonic temperature： 30-40℃ ultrasonic time： 7-11 min derivatization time： 20-100 min derivatization temperature： 50-90℃） for optimization design. A quadratic regression model was established to determine the optimal conditions and verify their reliability. The optimal conditions determined by single-factor experiments were ultrasonic temperature 35℃， ultrasonic time 9 min， derivatization temperature 70℃， and derivatization time 60 min. The response surface model （R²=0.9035） showed that the linear terms A and C， the interaction term CD， and the quadratic terms A²， C²， and D² had extremely significant effects on the results （P<0.01）， while the interaction term AD had a significant effect （P<0.05）. After optimization， 145 metabolites were detected， representing an increase of 198.60% compared with the pre-optimization level， with an error of 3.5%. Methodological validation showed that the peak area RSD of the internal standard L-2-chloro-phenylalanine was 8.2% （n=6）， and the signal-to-noise ratio （S∶N） was 9.9∶1， which met the requirements for metabolomic detection. This study established a pretreatment method for the detection of metabolites from rhizobia of Lespedeza daurica， providing a technical basis for their extraction and analysis.

As an important turfgrass and forage grass， perennial ryegrass （Lolium perenne L.） is frequently constrained by high temperature stress during its growth. To explore the effects of PvPCF5 gene functional repression on heat tolerance of perennial ryegrass and its correlation with photosynthesis， wild-type （WT）， PvPCF5 functional repression （PvPCF5-SRDX）， and overexpression （PvPCF5-OX） plants were used as experimental materials and divided into 2 groups with or without heat acclimation， followed by heat stress treatment at 42℃ for different durations. The results showed that under high temperature stress， PvPCF5-SRDX plants exhibited superior physiological performance compared with WT ones， with significantly higher relative water content， and significantly lower electrolyte leakage and malondialdehyde content （P<0.05）. Meanwhile， the photosynthetic pigment contents of PvPCF5-SRDX plants were significantly higher than those of PvPCF5-OX ones （P<0.05）， accompanied by the highest net photosynthetic rate， stomatal conductance and transpiration rate， as well as the lowest intercellular CO₂ concentration. In conclusion， repression of PvPCF5 gene function can effectively improve the photosynthesis of perennial ryegrass and thereby significantly enhance its high temperature tolerance. This study provides a theoretical basis for breeding new heat-tolerant perennial ryegrass varieties.

ERD15 （EARLY RESPONSIVE TO DEHYDRATION 15） is an important regulatory factor involving in plant stress responses. In this study， the MsERD15 gene from alfalfa （Medicago sativa L.） was cloned， and its potential role in stress tolerance was investigated through bioinformatics， expression profiling， and functional analyses. The MsERD15 gene was cloned by RT-PCR， and the physicochemical properties， conserved domains， and phylogenetic relationships of the encoded protein were analyzed. The expression patterns of MsERD15 under drought， high salinity， and abscisic acid （ABA） treatments were examined using qRT-PCR. A MsERD15-YFP fusion construct was generated for subcellular localization analysis， and heterologous expression in yeast was performed to evaluate its stress tolerance function. The results showed that the coding sequence of MsERD15 was 402 bp in length， encoding a protein of 134 amino acids. The gene was significantly induced by drought， high salinity， and ABA treatments. Subcellular localization indicated that the protein was localized in the cytoplasm. Expression of MsERD15 in yeast significantly enhanced tolerance to high salinity and polyethylene glycol （PEG） stress. These results indicated that MsERD15 participated in stress responses and night serve as a candidate gene for improving stress tolerance in alfalfa through molecular breeding.

To optimize the EMS-induced mutagenesis technology of forage oat （Avena sativa L.） and improve mutagenic efficiency， seeds of Oat cultivar ‘Qinghai 444’ and ‘Zhongtian No. 4’ were used as materials in this study. PEG osmotic priming was combined with EMS chemical mutagenesis to screen for optimum compound mutagenesis conditions for forage oat. Based on the germination characteristics and seedling traits of the M₁ generation in the two oat cultivars， the pretreatment conditions of 20% PEG for 3 h and 10% PEG for 6 h were found to promote seedling growth. The optimal EMS treatment conditions were 1% EMS for 16 h for ‘Zhongtian No.4’ and 0.75% EMS for 16 h for ‘Qinghai 444’. Through a comprehensive analysis of field agronomic traits at the milk stage in the M₂ generation after combined PEG and EMS treatments， it was found that 30% PEG for 3 h combined with the optimal EMS treatment produced the best results for developing germplasm with high-yield potential in both cultivars. Under these conditions， the mutagenesis efficiencies of the M₂ population were 2.40% for ‘Zhongtian No. 4’ and 1.26% for ‘Qinghai 444’， respectively， and a total of 22 germplasm lines with high-yield potential were obtained. These results provide a rich material basis for subsequent oat breeding.

To obtain high-yielding， high-quality， and anthocyanin-rich new germplasm of forage grass， in this study we utilized a diploid Pennisetum glaucum ‘Ningza No.4’ as the maternal parent and a tetraploid P. purpureum ‘purple’ as the paternal parent to conduct interspecific hybridization. The germination and seedling establishment rates of the hybrid F₁ seeds， along with authenticity verification， indicated that despite certain hybridization barriers between P. glaucum ‘Ningza No.4’ and P. purpureum ‘purple’， hybrid offspring could still be produced. Furthermore， it was confirmed that due to the similarity in DNA content between the parental lines， flow cytometry was not suitable for authenticity verification of the hybrid offspring； instead， a combination of chromosome counting and molecular marker methods proved to be more accurate and effective. Further integration of agronomic traits and nutritional quality measurements of parents and their hybrid offspring showed that parents and hybrid offspring exhibited significant differences. Some individual hybrid plants had a 46% higher fresh weight than their paternal parent and a 27% higher anthocyanin content. Multiple superior individual plants were selected and propagated. Data collected in the second year indicated that the superior hybrid lines outperformed the parental lines in terms of fresh forage yield， dry forage yield， and anthocyanin content. The triploid hybrid superior strain selected in this study showed excellent performance in terms of yield and anthocyanin content， providing important materials for the subsequent breeding of new forage varieties.

To overcome the limitations of an imperfect mutagenesis breeding system for Leymus chinensis and the shortage of germplasm with high seed setting rates， this study established an efficient mutagenesis technology using a combination of spatial and atmospheric pressure room-temperature plasma （SP+ARTP）. A high-throughput， accurate phenotypic analysis of large-scale mutant populations was achieved by utilizing an automatic seed setting rate identification model based on the YOLO algorithm. The results indicated that cultivar ‘Xiwuzhumuqin’ was the most suitable material for mutagenesis； a 60-minute treatment with 20% NaOH was the optimal pretreatment method. Single-space mutagenesis significantly promoted seed germination and seedling growth. The mutagenesis efficiency of the M₁ generation using the SP+ARTP combination reached 1.20%， and 23 new germplasm lines with high seed setting rate were successfully selected. These lines exhibited a seed setting rate of 30% higher than that of the control group. The combined mutagenesis and high-throughput phenotyping system developed in this study provides key technical support and germplasm resources for the targeted breeding of high-seed-setting L. chinensis varieties and their industrial application.

To develop a rapid quality detection model for oat （Avena sativa） hay applicable across environments， 849 samples were collected at three sites （Baoding and Zhangjiakou in Hebei， Guyuan in Ningxia） for two years. Crude protein （CP）， neutral detergent fiber （NDF）， acid detergent fiber （ADF）， soluble sugars （SS）， and total potassium （K） were measured. Prediction models were established using near-infrared spectroscopy （NIRS） combined with partial least squares regression （PLSR）. All five traits showed broad， near-normal distributions， indicating good sample representativeness. The CP， SS， and K models performed well， with cross-validation coefficients （R²） ≥ 0.89， ratio of performance to deviation （RPD） ≥ 3.0， and validation set correlations （r） of 0.84， 0.86， and 0.83， respectively， demonstrating strong external predictive ability. The NDF and ADF models achieved R² ≥ 0.85 and RPD ≥ 2.5， with r values of 0.78 and 0.79， meeting requirements for routine screening. Based on model predictions and forage quality standards， 56 high-quality forage oat accessions were identified. This study provides an efficient technical platform for high-throughput phenotyping and quality-based breeding in oat germplasm.

This study aimed to elucidate the effects of heterogeneous habitats on the reproductive strategies of clonal plants. By using the clonal bunchgrass Elymus excelsus in the Songnen Plain as the research objects， three habitats， roadside （H1）， riverside （H2） and meadow （H3） were established. The number of ramets， biomass， and reproductive traits were measured at the maturity stage and the post-fruiting stage. The results showed that， at the maturity stage， the number of reproductive ramets in H3， the height of reproductive ramets in H2 and H3， as well as inflorescence biomass and reproductive allocation II across all habitats， were significantly higher than those at the post-fruiting stage （P<0.05）. Significant differences in numerical and biomass traits were observed among different habitats. Overall， plants in H1 exhibited the best performance in reproductive and vegetative ramet number and biomass. In contrast， plants in H2 and H3 showed divergent patterns in growth and reproduction， with most reproductive traits in roadside habitats exceeding those in meadow habitats despite smaller tuft size. With the increasing of tuft size， the number and biomass of vegetative ramets， reproductive ramets and total ramets exhibited significant linear relationships across habitats and growth stages （P<0.05）. The results indicate that E. excelsus adapts to heterogeneous habitats by flexibly adjusting its numerical traits and biomass allocation.

To investigate the evolution pattern of ecological security in Qinghai Province， in this study we constructed an evaluation system based on the PSR （Pressure-State-Response） framework， integrated obstacle degree analysis with residual-corrected GM（1，1）-Verhulst modeling to identify constraining factors and conduct short-term forecasting. The results revealed that the comprehensive ecological security index in Qinghai Province increased from 0.54 to 0.66 during 2005-2023， with the security level upgrading from “Critical Security （Grade Ⅲ）” to “Relatively Secure （Grade Ⅳ）”. The evolution followed a trajectory of “response strengthening-state improvement-comprehensive enhancement”. Spatial distribution exhibited an “east-high west-stable” differentiation pattern， with eastern regions achieving the “Very Secure（Grade Ⅴ）” level ahead of others. The obstacle mechanism transitioned from early “pressure-dominated” to “state-response dual-constraint” type， indicating that ecosystem structural quality and environmental governance capacity have become critical limiting factors. Short-term prediction suggested that the ecological security index would approach 0.73 by 2028， stably maintaining a high-level “Relatively Secure（Grade Ⅳ）” status. Future efforts should shift from response enhancement to ecosystem resilience improvement， implementing differentiated zoning strategies to support national ecological security barrier construction.

Evaluation of the effect of degraded grassland restoration is of crucial for optimizing restoration measures and achieving sustainable utilization of grassland resources. However， current restoration evaluation mainly relies on manual ground surveys， making it difficult to meet the demands of large-scale， long-term dynamic monitoring. This study takes the restoration of degraded alpine grassland in Qilian Mountain National Park as an example. The spatial-temporal adaptive reflectance fusion model and multi-source remote sensing data were used to acquire a high spatial-temporal resolution NDVI dataset. Then the remote sensing estimation models for key grassland parameters were constructed to evaluate the restoration status of degraded grassland. The results show that （1） The models constructed based on high spatiotemporal resolution NDVI exhibited high accuracy， with R values of 0.82 and 0.89 and RMSE values of 12.02% and 32.36 g·m^-2 for the coverage and above ground biomass （AGB） models， respectively. （2） The inversion results show that grass growth conditions significantly improved after the implementation of restoration measures （P<0.05）， with coverage and AGB reached 1.32-2.17 times and 1.42-3.3 times of the values before the implementation of restoration measures， respectively. （3） Over the past 25 years， coverage and AGB increased at annual rates of 1.24% and 3.23 g·m^-2， respectively. The findings of this study provide technical support for evaluating the restoration effects of degraded alpine grasslands and offer a scientific basis for timely adjustments to restoration measures for degraded grasslands.

The mechanisms by which the root systems of invasive plants respond to nutrient and water deficiency remain poorly understood.In this study， we conducted a paired comparison between Asteraceae invasive plants （Senecio vulgaris， Symphyotrichum subulatum） and native plants （Senecio scandens， Aster ageratoides）， examined their root traits， Arbuscular Mycorrhizae Fungi （AMF） colonization rate， and biomass performance under normal and water and nutrient deficient conditions. The results showed that although both water and nutrient deficiencies reduced aboveground biomass and AMF colonization rates by more than 20% on average across all species， the invasive plants exhibited significantly greater aboveground biomass and higher AMF colonization rates compared to native plants. Nutrient deficiency significantly increased specific root length and specific root surface area， promoted root length and surface area of roots with diameters <0.5 mm， and reduced root tissue density in native plants， with average changes ranging from 8.23% to 32.64% in native plants. However， invasive plants showed opposite or no significant changes. With the exception of Symphyotrichum subulatum， water deficiency enhanced specific root length， specific root surface area， root length and surface area across all diameter classes， while reducing root tissue density in the other species. In summary， the invasive plants demonstrated stronger stress resistance. Under nutrient stress， invasive plants relied more on maintaining high AMF colonization， whereas native plants primarily depended on adjustments in root morphology. Under water deficiency， both invasive and native plants exhibited similar root adaptation strategies， but the invasive plants maintained higher AMF colonization. Combined stress responses tended to resemble those under single nutrient deficiency. These findings are important for elucidating the mechanisms underlying the adaptation of invasive plants to nutrient- and water-deficient environments.

The genus Elymus is an important native grass species for ecological restoration. Screening low nitrogen-tolerant germination germplasm and improving nitrogen use efficiency are one of the effective approaches for near-natural restoration of degraded grasslands. In this study， twelve indicators during germination and seedling growth stages of 60 Elymus germplasms were measured under low nitrogen （0.01 mmol·L^-1） and control （1.00 mmol·L^-1）conditions using the petri dish germination method. Their responses to low nitrogen were explored， and comprehensive evaluation of low nitrogen tolerance was conducted by combining membership function and systematic clustering analysis. The results showed that under low nitrogen stress， all the indicators of the germplasms were decreased. The average germination rate， germination vigor， germination index， seedling length， root length， seedling fresh weight， root fresh weight， total fresh weight， seedling dry weight， root dry weight， total dry weight， and root-shoot ratio decreased by 5.95%， 12.07%， 8.21%， 6.40%， 14.80%， 29.04%， 36.28%， 25.54%， 30.00%， 40.74%， 28.77% and 8.08%， respectively. There were significant differences in low nitrogen tolerance among the different germplasms. Seven germplasms， including E22， E58and E47， had a comprehensive low nitrogen tolerance coefficient exceeding 0.850， while E32 and E49 were below 0.66. Based on the low nitrogen tolerance coefficient， cluster analysis divided the tested germplasms into six categories： super-strong， medium-strong， low-strong， low-weak， medium-weak， and super-weak. Among them， 10 materials， including E47 and E22， were classified as super-strong low nitrogen-tolerant germplasms， and 3 materials， including E49 and E32， were classified as super-weak low nitrogen-tolerant germplasms. This study provides excellent parental materials for the mining and functional research of candidate genes related to Elymus low nitrogen tolerance， genetic improvement， and breeding of new varieties.

To investigate the role of exogenous selenium in regulating plant tolerance to saline-alkali stress， alfalfa （Medicago sativa L.） ‘WL298HQ’ was used as experimental material. Different concentrations of exogenous selenium were applied during seed germination and seedling stages to explore the effects on seed germination and physiological characteristics under mixed saline-alkali stress. The results showed that applying exogenous selenium at concentrations of 0.5， 1， and 2 mmol·L^-1 significantly promoted the germination of WL298HQ seeds under stress. The most pronounced promoting effect on seed germination was observed at 0.5 mmol·L^-1. Comprehensive analysis of various physiological indicators at the seedling stage revealed that 2 mmol·L^-1 exogenous selenium effectively alleviated the physiological damage caused by mixed saline-alkali stress to alfalfa seedlings. Mixed saline-alkali stress significantly inhibited the antioxidant capacity and increased cell membrane permeability of alfalfa. However， exogenous selenium application under mixed saline-alkali stress promoted plant growth， reduced the degree of membrane lipid peroxidation， and simultaneously enhanced the activities of various antioxidant enzymes in the leaves.

To screen Pennisetum forage varieties suitable for cultivation in the Chengdu Plain and surrounding ecological zones and clarify their production performance， nutritional quality， and cold resistance， Using nine elephant grass and hybrid Pennisetum varieties （lines） as materials， a three-year field experiment was conducted in Chongzhou. Agronomic traits， yield， nutritional quality， winter survival rate， and physiological indicators under low-temperature stress were measured. Comprehensive evaluation was performed using the membership function method and grey correlation degree analysis. GMY had the highest fresh yield （203 121 kg·hm^-2）， followed by CY1 （183 138 kg·hm^-2） and JMLC （168 798 kg·hm^-2）， respectively. CN005 had the highest soluble sugar content （91.19 mg·g^-1）. GM1 had the highest crude protein （6.82%） and crude fat （1.03%） content， indicating the best nutritional quality. CY1 achieved a winter survival rate of over 95% in low-altitude areas such as Chongzhou and Xinjin， and also showed stable performance in high-altitude cold areas such as Meigu， Sichuan， ranking first in the comprehensive evaluation of cold resistance physiology. GMY was suitable for promotion as a high-yielding variety， GM1 was suitable for silage， and CY1 possessed strong cold resistance， making it suitable for promotion in high-altitude areas. This study provides a scientific basis for variety selection and cold resistance mechanism analysis of Pennisetum in the Chengdu Plain and similar ecological zones.

To screen novel germplasm of Pennisetum purpureum with high-yield potential， 800 F₁ hybrid individuals were generated by crossing ‘Guimu 1’ hybrid P. purpureum （female parent） with F-AI P. purpureum （male parent）. SSR molecular markers were employed to authenticate true hybrids， followed by analyses of diversity， correlation， clustering， and principal components for 10 yield-related traits in the true hybrid population. The results revealed that 300 true hybrids were identified using two primer pairs （SSR24 and WSSR31）. The true hybrid population exhibited abundant phenotypic variation， with coefficients of variation ranging from 13.91% to 45.58% and diversity indices from 1.37 to 2.84. Correlation analysis demonstrated that all traits were highly significantly positively correlated with single-plant yield （P<0.01）， among which plant height showed the strongest correlations with fresh weight and dry weight， with correlation coefficients of 0.55 and 0.66， respectively. Heterosis analysis indicated that most yield-related traits of the F₁ generation displayed positive dominance， and the relative heritability of the female parent was stronger than that of the male parent. Principal component analysis extracted two principal components， accounting for a cumulative variance contribution rate of 64.819%， with plant height， single-plant dry weight， tiller number， and internode length identified as core influencing factors.

To address production problems such as low seed setting rate， in this study， a total of 300 Leymus chinensis accessions were evaluated across three consecutive years of field trials and systematically measured their four growth traits： Plant Height of Reproductive Branch at Heading Stage （PH_RBHS）， Plant Height of Reproductive Branch at Maturity Stage （PH_RBMS）， Leaf Length （LL）， Leaf Width （LW）， and eight seed setting-related traits： Spike Weight （SW）， Spike Length （SL）， Number of Spike Nodes （NSN）， Seed Setting Rate （SSR）， Number of Spikelets （NS）， Floret Number per Spikelet （FNPS）， and Seed Number per Spike （SNPS）. Diversity analysis and cluster analysis jointly revealed a rich genetic background within the population： the coefficient of variation ranged from 10.73% to 51.86%， and the genetic diversity index ranged from 1.853 to 2.068； the 300 accessions could be classified into four distinct clusters. Correlation analysis indicated that seed setting rate （SSR） was correlated to varying degrees with 11 traits， such as Spike Weight （SW）， Spike Length （SL）， and Seed Number per Spike （SNPS）. The first four principal components accounted for 79.26% of the total variance， effectively capturing most of the information of the original traits. Finally， based on the best linear unbiased estimate （BLUE） of phenotypic data， a comprehensive evaluation was conducted using a membership function analysis that integrated heading rate （HR） and seed setting rate （SSR）， and 50 elite accessions were identified. This study provides support for further gene mining， genotype-phenotype association analysis， and molecular breeding.

To investigate the variation patterns of fresh weight and cold tolerance traits in new breeding materials of Pennisetum purpureum， identify the main trait factors affecting fresh weight， and select superior materials with high fresh weight and strong cold tolerance， this study used 86 materials of P. purpureum as experimental subjects and analyzed twelve traits for diversity， correlation， regression， path， cluster and principal component analysis. The results showed that the coefficient of variation for each trait of the tested materials ranged from 6.45% （leaf length） to 18.17% （tiller number after regreening）， and the genetic diversity index ranged from 1.8992 （plant height） to 2.0958 （fresh weight）. Regression and path analysis indicated that regreening speed， leaf length， internode length， and stem diameter had significant direct positive effects on fresh weight. Cluster analysis classified the materials into four clusters， with cluster I exhibiting better comprehensive traits and cluster IV the worst. Principal component analysis extracted three principal components， with a cumulative contribution rate of 68.12%. Based on principal component scores， the comprehensive evaluation D value was calculated using the fuzzy membership function method combined with the contribution rates. According to the D value ranking， 17 P. purpureum breeding materials with relatively superior comprehensive traits， including GM1×F-Y189， GM1×F-Y557， and GM1×F-A591， were selected. These results can provide a phenotypic evaluation basis for breeding new high-fresh-weight and cold-tolerant P. purpureum varieties.

This study investigated the growth regulation mechanism of quercetin on seed germination and seedling growth of Apocynum venetum L. under salt stress， and determined its optimal application concentration. This study utilized A. venetum as the experimental material， and established eight treatments： HCKN： 200 mmol·L^-1 NaCl salt stress； Q₁+N-Q₆+N： 200 mmol·L^-1 NaCl +50， 100， 150， 200， 250， 300 μmol·L^-1 quercetin）. The study systematically measured seed germination traits （germination rate， germination vigor， germination index）， seedling growth indicators （plant height， root growth parameters， biomass， leaf growth parameters）， photosynthetic physiological traits （photosynthetic pigment content， chlorophyll fluorescence parameters）， and stress resistance physiological indicators （antioxidant enzyme activity， malondialdehyde content， proline content）. The alleviation effects were comprehensively evaluated using the membership function method. The results indicated that salt stress had a minor effect on the germination rate of A. venetum seeds but significantly reduced germination vigor and germination index. It severely inhibited the growth of A. venetum seedlings and impaired photosynthetic system function， characterized by significantly decreasing photosynthetic pigment content and PSII photochemical efficiency， along with increasing accumulation of malondialdehyde， a lipid peroxidation product.The salt stress-alleviating effect of quercetin exhibited a pronounced concentration-dependent response： Low quercetin concentrations （Q₁+N， Q₂+N） provided limited alleviation， while high concentrations （Q₅+N， Q₆+N） failed to effectively improve growth and even inhibited A. venetum seedling development. Compared to other quercetin concentration treatments， the 150 μmol·L^-1 quercetin （Q₃+N） treatment showed the best salt stress alleviation effect. Compared to the salt-stressed control （HCKN）， it increased seed germination potential and germination index by 2.1% and 3.5%， respectively. Seedling height increased by 97.2%， total chlorophyll content and carotenoid content increased by 17.1% and34.9% respectively， proline content increased by 20.6%， and malondialdehyde content decreased by 22.8% （P<0.05）. Concurrently， it significantly improved root morphology and chlorophyll fluorescence parameters， bringing seedling growth and physiological characteristics closer to the normal control level. Quercetin enhances salt tolerance in A. venetum seedlings by synergistically promoting photosynthetic pigment synthesis， strengthening antioxidant system function， regulating osmotic balance， and optimizing root structure， thereby effectively mitigating salt stress damage. This study identifies the optimal concentration and key physiological mechanisms by which quercetin regulates A. venetum’s salt tolerance， providing crucial technical guidance for large-scale cultivation and ecological restoration of A. venetum in saline-alkali soils.

Based on a long-term grazing experiment platform established in the Stipa breviflora desert steppe， this study analyzed the dynamic changes in the nutritional quality of two dominant plants Stipa breviflora and Cleistogenes songorica under different grazing intensities and duration. The results indicated that both moderate and heavy grazing significantly reduced the crude protein （CP） content of the both species. Heavy grazing significantly increased the neutral detergent fiber （NDF） content in the both species and significantly reduced the ether extract （EE） content of Cleistogenes songorica， while light grazing significantly reduced the crude ash content of Stipa breviflora. As the grazing season progressed， the CP content of the both species gradually decreased， whereas the ether extract and acid detergent fiber （ADF） contents exhibited an initial increase followed by a decrease. Specifically， the ether extract content of Stipa breviflora and Cleistogenes songorica peaked in August and July， respectively， while the ADF content for both species reached its maximum in July. Furthermore， CP significant negatively correlated with NDF， as well as between ether extract with crude ash. In contrast， NDF and ADF showed a significant positive correlation. These findings provide a scientific basis for improving the utilization efficiency of biological resources in the Stipa breviflora desert steppe of Inner Mongolia and contribute to the sustainable management of grassland ecosystems.

A deep analysis of the transformation trajectory and structural changes of land use in the Yellow River Basin is a key factor to enhance the sustainable utilization efficiency of land resources in the area. Using remote sensing （RS） and geographic information systems （GIS） technology， this study selected six periods of RS imagery from 1990 to 2018 as data sources. It combines geoscience information mapping and statistical methods to analyze the spatial patterns and structural characteristics of land use changes in the Yellow River Basin. The study found that： （1） Between 1990 and 2018， changes in cultivated land and construction land were the most dramatic， with a net decrease of 8663 km² in cultivated land and a significant increase of 13 109 km² in construction land； unused land decreased by 8131 km²， while forested and grassland areas experienced slight growth； （2） There were frequent conversions among different land types， particularly notable transformations among grassland， forestland， and cultivated land， as well as the conversion of cultivated land to construction land； （3） Although there were significant replacements in land use types over the 28 years， the overall land use pattern in the basin remained basically stable， with relatively smooth structural evolution， showing zonal differentiation characteristics from upstream to downstream. This study systematically revealed the temporal and spatial evolution patterns and structural transformation characteristics of land use in the Yellow River Basin， providing strong data support and decision-making references for spatial planning， ecological restoration， and land policy formulation in this region.

Enclosure is an important measure for restoring degraded grasslands， however， the effects of short-term enclosure on soil quality and multifunctionality of the alpine meadow remain unclear. In this study， we compared the two years effects between enclosure and free grazing （control） on soil physicochemical properties， plant community diversity and soil multifunctionality of a typical alpine meadow in the Xizang Three Parallel Rivers region. The results showed that： （1） short-term fencing significantly affected soil temperature， electrical conductivity and soil organic carbon （F₁=6.945， F₂=5.216， F₃=25.344， P<0.05）. （2） Compared with 2022， plant community diversity （0.966） and the importance value of Poaceae （19.296） were greater than those under fencing in 2023， whereas root-shoot ratio （17.671） and the importance value of Forbrich （8.215） were increased accordingly， as well as Cyperaceae （90.628）. （3） Mantel tests indicated that the correlations between plant diversity and soil physicochemical properties were strengthened in 2023. For grazing control treatment， plant communities were more sensitive to soil changes， while enclosure enhanced correlations between different soil factors. （4） Multifunctionality analysis presented results that ecosystem functions for this alpine meadow were relatively stable under short-term enclosure， whereas greater fluctuations at high-threshold occurred under a control grazing. Overall， the short-term enclosure had limited direct effects on soil physicochemical properties but may indirectly influence soil multifunctionality by regulating plant community structure.

In order to investigate the genetic structure and historical dynamics of natural populations of Xanthopappus subacaulis， we sequenced the DNAs of 147 individuals from 49 populations based on ten single-copy nuclear genes. Multiple methods， including STRUCTURE clustering and molecular variance analysis， were employed for analysis. The results indicated that the polymorphic loci of X. subacaulis ranged from 3 to 11， with haplotype diversity index （H_d） ranging from 0.558 to 0.883， nucleotide diversity index （π） from 0.001 32 to 0.006 03， and mean nucleotide differences （K） from 0.738 to 3.325， indicating rich genetic diversity. The tested populations of X. subacaulis could be divided into two major genealogical branches in the north and south， with 83.04% of the genetic variation among populations and only 16.96% within populations. The degree of genetic differentiation was high （F_ST=0.830， P<0.01）， and gene flow was extremely low （Nm=0.112）. The genetic distance was significantly positively correlated with the geographical distance （r=0.537，P<0.01）. The divergence time of the two major genealogical branches was approximately 3.33 million years ago， which was related to the uplift of the Qinghai-Xizang Plateau and the climate change during the Quaternary glacial period. Moreover， there was no recent population expansion. This study revealed the influence of geographical isolation， climate differences， and historical events on the genetic structure of X. subacaulis， which provided important data for its conservation of germplasm resources and adaptive evolution research.

Investigating the responding mechanisms of species diversity and community stability to disturbance has significant importance. This study examined the seasonal responses of species diversity and community stability to different grassland management practices （control， nitrogen application， mowing， mowing + nitrogen application） in the meadow steppe of Inner Mongolia. Research findings showed that nitrogen addition reduced species diversity overall， whereas mowing maintained higher species diversity. Species diversity and community stability exhibited asynchronous changes across different months within the growing season， yet showing an overall positive correlation. The Pielou evenness index demonstrated a highly significant positive correlation with community stability （P<0.01）. All grassland management measures enhanced community temporal stability， and significant improvements observed under mowing plus nitrogen application and mowing treatments （P<0.05）. Nitrogen addition reduced species asynchrony， whereas both mowing plus nitrogen application and mowing treatments increased species asynchrony. Community temporal stability showed a significant positive correlation with species asynchrony （P<0.05）. Species diversity and species asynchrony jointly maintained community stability. Mowing enhanced species diversity and asynchrony， thereby promoting community stability. Nitrogen addition reduced species diversity， but this negative impact could be mitigated through mowing. The findings of this study provide a reference basis for sustainable grassland management.

To elucidate the mechanism by which grazing intensity affects ecosystem multifunctionality （EMF） in alpine grasslands. In this study， the alpine grassland of Qinghai Lake was selected as the study area. Four treatments were set up， including grazing prohibition， light grazing， moderate grazing and heavy grazing. The effects of grazing intensity on plant functional traits， soil factors and ecosystem multifunctionality （EMF） were analyzed. The results showed that grazing intensity significantly changed plant community traits （P<0.05）. As grazing intensity increased， community-weighted height and leaf area decreased， while leaf nitrogen and phosphorus contents increased. Aboveground and belowground biomass significantly declined under heavy grazing （P<0.05）. The soil exhibited a decoupling character of nitrogen and phosphorus， with nitrate-nitrogen and ammonium-nitrogen decreasing while total phosphorus and available phosphorus accumulated. Moderate grazing had the most pronounced effects on soil moisture and pH （P<0.05）. The functional dispersion index increased with grazing intensity， and EMF peaked under moderate grazing. The structural equation model showed that grazing indirectly affected ecosystem multifunctionality （EMF） by regulating plant traits， functional dispersion index， and soil quality index （SQI）， with soil quality being the key driving factor. This study elucidated the intrinsic mechanism by which grazing intensities influences EMF through the coordination of plant functional strategies and soil nutrient patterns， providing a theoretical basis for the scientific management of alpine grasslands around Qinghai Lake.

Mycorrhizal respiration （R_Myc） significantly affects the carbon cycling in terrestrial ecosystems， yet its contribution potential and main influencing factors remain unclear. In this study， a meta-analysis was conducted by using 105 datasets from 41 publications. By employing a mesh exclusion method to distinguish soil respiration components， we quantified the average contribution of R_Myc to soil autotrophic respiration （R_Auto） and total soil respiration （R_T）， and compared the differences between arbuscular mycorrhizal （AM） and ectomycorrhizal （ECM） contributions. The results showed that the average contribution rates of R_Myc to R_Auto and R_T were 38.55% and 16.87%， respectively. Specifically， the average contributions of AM and ECM to R_T were 16.78% （ranging from 2.48% to 32.00%） and 16.73% （ranging from 3.00% to 54.47%）， respectively. Correlation analysis indicated that the R_Myc rate was significantly negatively correlated with absolute longitude， mean annual precipitation， soil total nitrogen， and soil total phosphorus， while it was significantly positively correlated with soil pH and fine root biomass. Over all， R_Myc is an important component of soil respiration， and is affected by environmental factors， soil nutrient supply， and symbiotic relationships. This study revealed the contribution of mycorrhizal respiration to soil carbon fluxes at a global scale， providing a scientific basis for improving soil carbon cycle models.

This experiment aimed to address the problem of growth inhibition of Avena sativa L. under shading and low light conditions between photovoltaic panels. Using ‘Kona’ oats and plant regulator melatonin （MT） as materials， treatments， including a normal light control （CK-Z）， a shading stress control （CK-F）， and treatments with 20， 40， 60， 80， and 100 mg·L^-1melatonin （MT） sprayed under shade a pot experiment were conducted. The growth and physiological indicators at 30 and 50 days after emergence were measured， and the regulatory effect was evaluated by correlation analysis and membership function. Compared with CK-Z， CK-F significantly reduced oat stem thickness， dry weight， and antioxidant enzyme activity， while increasing plant height， fresh weight， and MDA （Malondialdehyde） content （P<0.05）； Spraying MT could improve its growth physiological indicators， with a significant positive correlation between stem thickness and fresh weight， dry weight， etc. （P<0.01）， a positive correlation between SOD （Superoxide dismutase） and plant height （r=0.075， P<0.05）， and a negative correlation between MDA and dry weight； The membership function indicated that the comprehensive evaluation value （D=0.89） was the highest when treated with 80 mg·L^-1 MT for 50 days. Exogenous MT enhanced the antioxidant system and alleviated shade stress. The optimal combination of 80 mg·L^-1 MT treatment for 50 days provided a solid theoretical basis for improving oat shade tolerance and grass cultivation in photovoltaic areas.

In this study， the forage oat （Avena sativa L.） cultivar ‘Zhongtian No. 4’ was used as the experimental material to establish an optimized ethyl methanesulfonate （EMS） mutagenesis system. A series of pretreatments steps were employed， including husk removal and a 30-hour seed moisture conditioning period， followed by EMS mutagenesis treatments at different concentrations and durations， and a post-treatment involving exogenous gibberellin application. An M₂ mutant population was constructed. Agronomic traits were investigated at the milk stage to evaluate the mutagenic effects and to screen the high-yielding germplasm. The results indicated that soaking seeds in 98% concentrated sulfuric acid for 6 minutes effectively removed the husk barrier of forage oat seeds. Adjusting seed moisture content to 50% via a 4-hour soaking facilitated efficient penetration of EMS into the seed. The optimal EMS mutagenesis conditions for forage oat were determined to be 1.0% EMS treatment for 16 hours. Treatment of mutagenized seeds with 50 mg·L^-1 exogenous gibberellin significantly improved seedling growth. Compared with the control without added gibberellin， the germination rate increased by 8.5%， and the seedling length also recovered to the level of the non-mutagenized seedlings. This EMS mutagenesis technique systematically addressed key limiting factors in forage oat， including seed permeability barriers， inconsistent physiological states， and mutagen-induced damage. In the M₂ generation， the mutagenic efficiency for obtaining high-yield potential germplasm reached 1.92%， and 13 elite high-yield potential germplasms were successfully identified.

To investigate the effects of various additives on the quality and microbial diversity of mixed silage prepared from tea stems （Camellia sinensis） and broad bean straw （Vicia faba）， mixed at a ratio of 2：8， the experiment comprised one control group （CK） and four treatment groups： T₁ （with Lactobacillus acidophilus added）， T₂ （with Lactobacillus plantarum added）， T₃ （with Bacillus subtilis added）， and T₄ （with a mixture of Lactobacillus plantarum and Bacillus subtilis added）， with three replicates per group. After 60 days of ensiling， the sensory quality， ensiling quality and microbial diversity were analyzed. Results indicated that all the additive treatments significantly improved sensory scores compared to CK （P<0.05）. Compared with CK， all treatment groups exhibited significantly higher concentrations of water-soluble carbohydrates （WSC） and significantly lower pH values （P<0.05）. Crude protein content increased significantly in T₂， T₃， and T₄ （P<0.05）， while the lactate-to-acetate ratio was significantly elevated in T₁， T₂， and T₄ （P<0.05）. Microbial profiling revealed a significant reduction in the relative abundance of certain Lactobacillus operational taxonomic units （OTUs） in T₁， T₂， and T₄—suggesting potential niche competition or functional redundancy among lactic acid bacteria （P<0.05）. Notably， the T₄ group displayed significantly greater phylogenetic diversity （PD_whole_tree index） and alpha diversity （Shannon index） than CK （P<0.05）. Furthermore， principal coordinate analysis indicated that bacterial community composition in T₁， T₂， and T₄ correlated positively with both WSC content and relative feed value （RFV）. Collectively， these findings demonstrate that microbial additives enhance silage fermentation quality and reshape the silage microbiome； moreover， distinct additives confer complementary benefits across key quality and ecological metrics.

This study investigated the effects of inoculation with feruloyl esterase-producing lactic acid bacteria Lactobacillus reuteri A4-2 on the fermentation quality， antioxidant status， and in vitro digestibility of baled alfalfa silage. Chopped fresh alfalfa （Medicago sativa L.） at the early to full-blossom flowering stage was randomly divided into three groups： CON （without inoculant）， YM13 （inoculated with non-feruloyl esterase-producing L. reuteri YM13）， and A4-2 （inoculated with L. reuteri A4-2）. Samples were collected after 20， 40， and 60 d of ensiling to determine fermentation characteristics， free ferulic acid content， antioxidant enzyme activities， chemical composition， and in vitro dry matter digestibility. Compared with the CON and YM13， inoculation with L. reuteri A4-2 significantly reduced pH but increased lactic and acetic acid contents （P<0.05）. Both inoculating L. reuteri YM13 and L. reuteri A4-2 in silage showed a higher dry matter content and lower ammonia nitrogen/total nitrogen than CON （P<0.05）. Inoculation with L. reuteri A4-2 in alfalfa silage markedly enhanced the levels of free ferulic acid， superoxide dismutase （SOD）， catalase （CAT）， glutathione peroxidase （GPX） activities， and total antioxidant capacity （T-AOC） （P<0.05） relative to CON and YM13 during ensiling. In addition， inoculation with L. reuteri A4-2 effectively decreased neutral detergent fiber （NDF） and acid detergent fiber （ADF） contents， thereby improving in vitro DM digestibility compared with the other treatments （P<0.05）. Overall， inoculation with L. reuteri A4-2 not only improved the fermentation quality of silage， but also enhanced the antioxidant capacity， reduced its fiber content， and improved its in vitro DM digestibility compared with the CON and YM13 groups， demonstrating significant application advantages.