To investigate the antioxidant physiological regulatory mechanisms during the germination of naturally aged alfalfa （Medicago sativa） seeds， this experiment used ‘Zhongmu No.1’ and ‘Zhongmu No.2’ alfalfa seeds stored for 4 and 7 years， respectively， as experimental materials. After being imbibed at different stages， seed germination indices， antioxidant enzyme activities of the ascorbic acid-glutathione （AsA-GSH） cycle， and antioxidant contents were measured to analyze the changes in antioxidant indices of alfalfa seeds during storage. The main results are as follows： storage for 7 years significantly reduced the germination capacity of alfalfa seeds， specifically manifested by decreases in germination potential， germination rate， germination index， vitality index， and seedling root length with increasing storage duration. Storage duration had little effect on the initial water absorption rate of seeds but influenced the progression of the imbibition stage. As storage time increased， the lag phase during the imbibition of alfalfa seeds was prolonged. Natural ageing leads to a decline in the function of the AsA-GSH cycle during imbibition. Compared to seeds stored for 4 years， alfalfa seeds stored for 7 years exhibited significantly reduced activities of catalase （CAT）， glutathione reductase （GR）， and monodehydroascorbate reductase （MDHAR） . Ascorbic acid （AsA） and glutathione （GSH） content decreased， and oxidised glutathione （GSSG） accumulated， indicating weakened reactive oxygen species （ROS） scavenging capacity and exacerbated membrane lipid peroxidation. Seeds stored for 4 years exhibited enhanced antioxidant capacity during the mid-to-late stages of imbibition by upregulating the activity of certain antioxidant enzymes， such as peroxidase （POD） and GR， thereby partially delaying the excessive accumulation of ROS. Using the membership function method， the germination capacity of alfalfa seeds was ranked as follows： ‘Zhongmu No.1’ 4 a > ‘Zhongmu No.2’. 4 a > ‘Zhongmu No.1’ 7 a > ‘Zhongmu No.2’ 7 a. Compared to the ‘Zhongmu No.2’ seeds， under natural ageing conditions， Zhongmu No. 1 exhibited relatively stable vigor and physiological status， demonstrating stronger storage tolerance.

To identify the SWEET genes in Avena sativa and its responses to drought and salinity-alkalinity stress， this study systematically characterized the AsSWEET gene family using bioinformatics approaches and analyzed their expression patterns under drought and salt-alkali stress conditions by RT-qPCR. A total of 37 AsSWEET genes were identified and mapped to 19 chromosomes. All AsSWEET proteins contained the conserved MtN3_saliva domain， most members possessed seven transmembrane helices （TMHs）， and subcellular localization prediction indicated that they were primarily located on the plasma membrane. Phylogenetic analysis revealed that AsSWEET proteins could be classified into four major clades and shared high homology with SWEET proteins from Hordeum vulgare. Promoter analysis showed that AsSWEET family members harbored numerous cis-acting elements associated with light responsiveness， hormone signaling， development， and abiotic stress responses. Expression profiling indicated that 10， 7 and 18 AsSWEETs genes were significantly upregulated in leaves under drought， salt and alkali stress， respectively. Among them， AsSWEET15a and AsSWEET15c exhibited consistently high expression levels across all stress conditions， suggesting that they might serve as key candidate genes involved in oat tolerance to drought and salt-alkali stress. These findings provide theoretical insights into the functional roles of the AsSWEET gene family in abiotic stress responses and offer potential gene resources for molecular breeding of stress-tolerant oat varieties.

To better understand the gene regulatory network during seed development in Pennisetum glaucum， this study performed transcriptome analysis using seeds at the flowering stage （F） and grain-filling stages （S₁， S₂， S₃）. The results revealed the highest number of differentially expressed genes （DEGs） in the S₁ vs F comparison， totaling 7166. Pathway enrichment analysis demonstrated that plant hormone signal transduction， starch biosynthesis， and phenylpropanoid biosynthesis played important roles in seed development， with 160， 19， and 51 DEGs enriched in these pathways， respectively. These genes exhibited stage-specific high expression during seed development； among which， AUX1 and GID1 were highly expressed in early seed development， while ethylene signaling genes （ETR， EIN2， EIN3） increased in expression as seeds matured. Among the DEGs， 859 transcription factors （TFs） were identified， including members of AP2/ERF and bHLH families， primarily involved in seed development-related pathways such as plant hormone signaling and circadian rhythm. This study constructed a gene expression profile for P. glaucum seeds development based on transcriptome data from different stages， providing a reference for further research of its molecular mechanism.

Larvae of Galeruca daurica are the major pest that severely damages the grasslands of Inner Mongolia. To explore the molecular mechanisms by which 20-hydroxyecdysone （20E） regulates the development of its larval， transcriptome sequencing was conducted on 3rd-instar larvae treated with 20E for 48 hours by using the Illumina HiSeq^TM 4000 platform. A total of 75 536 Unigenes were obtained， among which 40 161 were functionally annotated. Compared with the control group， a total of 500 differentially expressed genes （DEGs） were identified， including 258 upregulated and 242 downregulated ones. GO and KEGG analyses revealed that the DEGs were significantly enriched in terms/pathways such as ion transport， catalytic activity， longevity regulating pathway-multiple species， and FOXO signaling pathway. Furthermore， 11 ecdysone-related genes were screened out. The qRT-PCR verification results confirmed the reliability of the sequencing data. The results indicated that 20E may regulate the growth and development of G. daurica larvae by affecting multiple metabolic pathways. This study systematically analyzed the transcriptomic characteristics of G. daurica larvae in response to 20E regulation， providing a theoretical basis for clarifying its developmental mechanism and screening green control targets.

To determine the drought-tolerant capacity of bromus and to screen early drought-tolerant bromus seedlings， this study measured the adaptive response of 101 accessions of B. inermis at the seedling stage to drought stress. The morphological and physiological changes of the plants including roots were analyzed， and 17 growth indexes related to drought tolerance were determined. The drought tolerance of the seedlings was evaluated and screened by comprehensive evaluation， correlation analysis， principle component analysis， membership function and cluster analysis. The results showed that plant height， average root diameter， fresh weight above ground， total root volume， root surface area， root projected area， fresh weight below ground， total primary root length， dry-weight root aboveground ratio， maximum primary root long， fresh-weight root aboveground ratio and aboveground dry weight can be important indicators for the identification of drought tolerance in the seedlings of bromus. 101 bromus materials were divided into 4 different drought-tolerant grades by cluster analysis. There were 10 germplasm materials in class I with D value ranging from 2.00 to 2.55， which were highly drought-tolerant materials. There were 38 germplasm materials in Class II with D value ranging from 1.27 to 1.81， belonging to moderate drought tolerance. There were 42 germplasm materials in Class III with D value ranging from 0.77 to 1.25， belonging to low drought tolerance. There were 11 germplasm materials in Class IV， the D value ranged from 0.37 to 0.73， belonging to drought sensitive materials. The drought-resistant germplasm W1Z755， W1Z770 and W1Z696 were selected. The drought-sensitive materials were W1Z626， W1Z587 and W1Z763. This study can provide a theoretical basis and a material basis for the drought resistance evaluation of bromus seedlings and the selection of new varieties.

Multi-element stoichiometric coupling is critical for plant growth. To investigate the effects of mixed cultivation of leguminous and gramineous forages on their multi-element stoichiometric characteristics in the Bashang agro-pastoral ecotone， this study used the monoculture of Medicago sativa and Bromus inermis as the control treatment and further analyzed the influences of two mixed sowing combinations， i.e.， M. sativa+B. inermis （MW） and M. sativa+B. inermis+Elymus nutans （MWP）， on plant nitrogen and phosphorus stoichiometric characteristics， macro-element （potassium， calcium， magnesium， sulfur） contents， and microelement （iron， manganese， copper， zinc， nickel） contents. The results showed that the nitrogen and phosphorus contents of M. sativa and B. inermis in the monoculture treatment were higher than those in the MW and MWP mixed sowing treatments. The ratio of nitrogen to phosphorus （N∶P ratio） of M. sativa in the monoculture treatment showed no difference compared to those in the MW and MWP mixed sowing treatments （all exceed 16）， indicating the phosphorus limitation of M. sativa. However， the N∶P ratio of B. inermis in the monoculture treatment was lower than those in the MW and MWP mixed sowing treatments， indicating a shift from nitrogen limitation to phosphorus limitation or dual limitation of nitrogen and phosphorus of B. inermis. Except for the zinc content of B. inermis， no differences in the macroelement and microelement contents of M. sativa and B. inermis were observed between monoculture treatments and mixed sowing treatments. In conclusion， nitrogen and phosphorus limitations might still exist in the leguminous and gramineous mixed sowing grassland in the Bashang agro-pastoral ecotone.

Aiming at the problems of a single evaluation system for the regeneration ability of alfalfa （Medicago sativa L.） under high-frequency cutting and unclear mechanisms of varietal differentiation， this study took 9 alfalfa varieties as materials， determined the plant height， growth curve， biomass， photosynthetic parameters， and non-structural carbohydrate content after cutting， and conducted a comprehensive evaluation using the membership function method. The results indicated significant differences in regrowth performance among the various cultivars. Among them， ‘WL363HQ’ exhibited outstanding performance， with a mean daily plant height increase of 1.93 cm， which was significantly higher than that of the other tested cultivars. In contrast， the ‘Beiji Star’ cultivar demonstrated the weakest overall performance. Through systematic evaluation of the regrowth capacity differences among the alfalfa cultivars， this study confirmed that under high-frequency cutting conditions， ‘WL363HQ’ possessed the strongest regrowth ability among the nine tested cultivars， while ‘Beiji Star’ showed the weakest regrowth capacity. These findings provide a theoretical basis for the selection and breeding of alfalfa cultivars with enhanced tolerance to frequent cutting.

To evaluate the effects of intercropping arrangements on phosphorus use efficiency and interspecific competition in legume-grass mixtures， same-row intercropping （T） and alternate-row intercropping （Y） was conducted by the pot experiment. The study investigated the relationships among phosphorus use efficiency （PUE）， interspecific competition， and the overyielding effect in triticale-hairy vetch and triticale-common vetch systems. The results showed that for the triticale-hairy vetch mixture， yield and overyielding were higher in the same-row arrangement， whereas the triticale-common vetch mixture was the opposite. The relative yield （RY） was higher in the alternate-row arrangement for both systems. Metrics including encroachment rate （A）， competition rate （CR）， and relative crowding rate （K） indicated that triticale was the competitively dominant species. Phosphorus use efficiency varied in the triticale-hairy vetch system， and it was higher for triticale under alternate-row but higher for hairy vetch under same-row intercropping； in the triticale-common vetch system， both species showed higher PUE in the alternate-row arrangement. Threshold analysis revealed that highly competitive ability coupled with high PUE synergistically induced the overyielding effect under the alternate-row arrangement. In conclusion， for establishing annual forages in the cool region of Zhaosu， the alternate-row intercropping of triticale and common vetch is recommended.

To screen alfalfa （Medicago sativa L.） germplasm suitable for cultivation on saline soils， this study evaluated the salt tolerance of 59 alfalfa germplasm accessions during the germination stage. Six parameters—germination potential （GP）， germination rate （GR）， germination index （GI）， vigor index （VI）， root length （RL）， and shoot length （SL） were measured. A comprehensive evaluation was conducted using coefficient of variation analysis， correlation analysis， principal component analysis （PCA）， subordinate function analysis （SFA）， and cluster analysis. The results revealed significant variation in salt tolerance during germination among the 59 alfalfa accessions. Based on PCA and correlation analysis， four key indicators were selected for salt tolerance evaluation： relative germination potential （RGP）， relative germination rate （RGR）， relative germination index （RGI）， and relative shoot length （RSL）. Cluster analysis based on D-values derived from SFA classified the 59 germplasms into five salt tolerance categories： highly salt-tolerant （1 accession）， moderately salt-tolerant （22 accessions）， low salt-tolerant （11 accessions）， salt-sensitive （11 accessions）， and highly salt-sensitive （14 accessions）. Seven accessions exhibiting strong salt tolerance were identified： ‘Juneng 6’‘Ningmu No.1’‘Salt treasure’‘Shockwave’‘Aohan’‘Hunter River’ and ‘Challenger’. These findings provided a theoretical basis for alfalfa salt tolerance breeding.

To evaluate the differences in salt tolerance among different alfalfa （Medicago sativa L.） cultivarsunder salt stress conditions and screen high-quality salt-tolerant germplasm resources，this study used 25 alfalfa cultivars as experimental materials， with two treatments of salt stress （200 mmol·L^-1 NaCl solution）and control （ultrapure water）. Germination and growth parameters were measured during the germination period （eight indicators， such as germination energy and germination rate， etc.） and seedling stage （six indicators， such as plant height and branch number， etc.）， and a comprehensive evaluation of salt tolerance was conducted using methods such as membership function value， comprehensive salt tolerance （D value）， and cluster analyses. The results showed that salt stress significantly reduced all germination parameters， with the seed vigor index exhibiting the highest reduction rate （-92.26%）， whereas the seedling dry weight was the least affected （-11.76%）. Cluster analysis classified the 25 alfalfa cultivars into five salt tolerance grades at the germination stage： included 2 of the strongest salt-tolerant cultivars， 4 strong salt-tolerant cultivars， 5 moderate salt-tolerant cultivars， 10 weak salt-resistance cultivars， and 4 salt-sensitive cultivars. Further evaluation of salt tolerance of 12 representative alfalfa cultivars during the seedling stage revealed salt stress had extremely significant effects on the plant height， above-ground fresh weight， relative water content， and electrical conductivity of alfalfa （P<0.01）， with significant differences between cultivars. By integrating the indicators of both germination and seedling stages， the three strongest salt-tolerant cultivars， namely ‘Xinmu No.4’‘Zhongmu No.4’， and ‘Bara520YQ’， were ultimately selected as important germplasm resources for salt-tolerant breeding and cultivation in saline-alkali soil regions.

Drought is one of the primary stress factors affecting plant production， and the germination stage is the most vulnerable period in the plant life cycle. In the breeding of drought-resistant Bromus inermis， evaluating drought tolerance during the germination stage is particularly important. This study employed the double-layer filter paper germination method， measuring eight indicators-including germination rate， germination potential， germination index， root length， and shoot length-under 25% PEG-6000 stress for 100 B. inermis germplasm resources. Principal component analysis， membership functions， and hierarchical clustering analysis were used to comprehensively assess drought tolerance during the germination stage. The results showed that， compared to the control， all observed indicators decreased under 25% PEG stress， with coefficient of variation ranging from 20.853% to 97.876%. There was a significant correlation （P<0.05） among most experimental indicators. There were substantial differences in drought tolerance among materials， with the comprehensive drought tolerance coefficient ranging from 0.612 to 0.169 and the D-value ranging from 0.861 to 0.068. Cluster analysis classified the 100 t100 Bromus inermis germplasm resources into four groups： highly drought-resistant （14 materials）， moderately drought-resistant （34 materials）， weakly drought-resistant （45 materials）， and drought-sensitive （7 materials）. This study identified drought-resistant germplasm such as W1Z622， W1Z627， and W1Z595. The research provides high-quality materials and theoretical support for drought-resistant breeding of B. inermis.

This study investigated the effects of Pb stress on the physiology of seed germination and the antioxidant system and Pb accumulation in seedlings of alfalfa （Medicago sativa）. Six Pb stress concentrations were set to evaluate seed germination physiology， and three Pb stress concentrations were established to assess the activity of the antioxidant system and Pb content in seedlings. The results showed that： （1）Pb stress inhibited seed imbibition and germination， reduced the activities of amylase and protease， and decreased the levels of soluble sugars， reducing sugars， free proline， and free amino acids. （2）The suitable concentration for Pb during seed germination of alfalfa was ≤1.84 mmol·L^-1， with a half lethal concentration and a limit concentration of 3.93 mmol·L^-1 and 7.29 mmol·L^-1， respectively. （3）Under 2.0 mmol·L^-1 Pb stress， the antioxidant system activity in seedling leaves initially increased and then decreased. At 4.0 mmol·L^-1 Pb stress， the antioxidant system collapsed， and oxidative damage intensified. （4）Under Pb stress， Pb content in seedlings significantly increased， with the highest levels in roots， followed by stems and leaves. Only a small amount of Pb translocated from underground to aboveground parts. This indicates that Pb stress inhibited seed germination， exacerbated oxidative damage in seedlings， led to the collapse of the antioxidant system， and caused substantial Pb accumulation in seedling roots. The study provides a theoretical basis for using alfalfa to remediate Pb-contaminated soils.

The aim of this study was to screen low phosphorus-tolerant oat （Avena sativa L.） varieties and to investigate their morphophysiological response mechanisms. Thirty oat varieties were used as materials， and two treatments of normal phosphorus （1000 μmol·L^-1 KH₂PO₄， CK） and low phosphorus （10 μmol·L^-1 KH₂PO₄， LP） were set up by hydroponics. Morphological and physiological indexes were measured after 21 days， and principal components， subordinate functions， and cluster analyses were used for the comprehensive evaluation. The results showed that low phosphorus stress significantly inhibited the aboveground growth of most oat seedlings， but promoted root development. Physiologically， low phosphorus treatment led to a decrease in phosphorus uptake and a significant increase in phosphorus utilization efficiency in most seedlings； soluble sugar content， acid phosphatase and nitrate reductase activities generally increased. Through systematic evaluation， ‘Weidu You No.5’ （D=0.818） and ‘Jin Yan No. 17’ （D=0.643） were identified as the most low-phosphorus-tolerant varieties， whereas ‘Ba You No. 18’ （D=0.341） and ‘Jun Ma’ （D=0.366） were the most sensitive ones. The results of this study provide a theoretical basis and material foundation for the selection and breeding of low phosphorus tolerant oat varieties.

The purpose of this study was to establish an efficient method for identifying the salt tolerance of oats （Avena sativa L.） during the germination stage， and to screen our excellent parents for salt-tolerant breeding. Using the petri dish paper germination method， 332 oat germplasms were subjected to a salt stress treatment with 0.80% （136.89 mmol·L^-1） NaCl solution. Eight indicators such as germination potential were measured. The salt tolerance was comprehensively evaluated and classified by combining the weighted membership function method with cluster analysis. Salt stress significantly inhibited all eight measured indicators. Correlation analysis revealed that highly significant positive correlations among these indicators. The 332 germplasms were classified into five salt tolerance grades： 34 highly salt-tolerant， 83 salt-tolerant， 116 moderately salt-tolerant， 51 salt-sensitive， and 48 highly salt-sensitive accessions. Regression analysis identified the salt tolerance index of root length （STI-RL） and the salt tolerance index of bud fresh weight （STI-BFW） as key indicators for evaluating salt tolerance during germination. Based on two-year evaluations， six materials demonstrated stable salt tolerance and can be utilized as parents in salt-tolerant breeding programs. Comparative analysis indicated that a higher proportion of Avena sativa L. accessions exhibited stronger salt tolerance compared to Avena nuda L. accessions. The 34 highly salt-tolerant germplasms provided excellent resources for salt-tolerant breeding and gene mining.

To investigate the effects of soda-alkali stress at different concentrations on seed germination and seedling growth of pearl millet （Pennisetum glaucum）， twelve genotypes of pearl millet germplasms were used as experimental materials. Using the Petri dish filter paper germination method， soda-alkali stress was simulated by preparing mixed solutions of NaHCO₃ and Na₂CO₃ at a molar ratio of 9∶1， with concentration gradients of 0， 40， and 60 mmol·L^-1. Germination-related parameters， encompassing germination rate， germination potential， germination index， vigor index， radicle emergence length， and plumule development length， were measured during the seed imbibition phase. A comprehensive evaluation framework for assessing soda-alkali stress tolerance was established through fuzzy membership function analysis combined with principal component clustering methodology. The results demonstrated that soda-alkali stress significantly inhibited seed germination and seedling growth of pearl millet， with the inhibitory effects intensified as the concentration of soda-alkali solution increased. Furthermore， substantial genotypic variation was observed in soda-alkali stress tolerance during the germination stage among different pearl millet genotypes. Cluster analysis classified the 12 genotypes into four distinct categories： （1） soda-alkali tolerant type （represented by Ca1165， accounting for 8.33%）， （2） moderately tolerant type （including Ca399， Ca727， Ca396， Ca742， and Ca382， comprising 41.67%）， （3） sensitive type （comprising Ca425， Ca481， Ca736， and Ca406， representing 33.33%）， and （4） highly sensitive type （consisting of Ca424 and Ca397， accounting for 16.67%）.

A sand culture pot experiment by using a two-factor completely randomized design was conducted to investigate the growth patterns of Trisetum tibeticum seedlings under nitrogen， phosphorus， potassium deficiency， and water shortage conditions. The experiment included four nutrient treatments： complete nutrition （CN）， nitrogen deficiency （ND）， phosphorus deficiency （PD）， and potassium deficiency （KD）. And four water treatments： 80% field capacity （W₁）， 60% field capacity （W₂）， 40% field capacity （W₃）， and 20% field capacity （W₄）. The results showed that plants of ND treatment exhibited stunted growth with withered leaves， leaves of PD treatment appeared dark green， and leaves of KD treatment showed yellowing and curling at the tips. Water shortage reduced plant height， and growth rates of ND and PD treatments showed declining trends after three weeks. Nutrient-water interactions significantly influenced leaf length， leaf width， root length， root surface area， root volume， above-ground and below-ground biomass， and root-to-shoot ratio （P<0.05）. Under different water conditions， ND treatment consistently resulted in the shortest leaf length， while CN treatment exhibited the greatest leaf width. Water shortage promoted root development in CN treatment， with the largest root surface area and root volume observed at W₄. ND and PD treatments increased the root-to-shoot ratio， with biomass allocation shifting towards below ground parts， while KD had no significant effect on the root-to-shoot ratio. Therefore， the interaction between water shortage and nutrient deficiency synergistically inhibits the growth of Trisetum tibeticum. In seedling cultivation of Trisetum tibeticum， enhanced growth monitoring and timely targeted supplementation should be implemented.

To clarify the invasion pathways of the Dociostaurus maroccanus （Thunberg） into the Ili region of Xinjiang， China， this study used the Hybrid Single-Particle Lagrangian Integrated Trajectory Model （HYSPLIT） combined with the flight parameters of D. maroccanus and the corresponding meteorological data during its invasion to analyze the invasion trajectories of this locust under the condition of 850 hPa. The results showed that the northwest wind prevailed in Xinjiang from June to August， with an average wind speed of approximately 3 m·s^-1， which provided favorable conditions for the invasion of D. maroccanus. In the backward trajectory analysis from June to August， the probabilities of D. maroccanus invading via the route from Kazakhstan to Huocheng County were 91.66%， 100%， and 83.87%， respectively. Among these， the trajectories in June were the most consistent with the biological characteristics and occurrence patterns of D. maroccanus， further confirming that the invading population of D. maroccanus in China was originated from the Almaty Region of Kazakhstan.

This study investigated the effects of different grazing intensities on leaf functional traits and aboveground biomass of Stipa breviflora and Cleistogenes songorica in desert steppe of Inner Mongolia. Based on the long-term grazing platform， no grazing （CK）， light grazing （LG）， moderate grazing （MG） and heavy grazing （HG） treatments were set up. The relationships between aboveground biomass of plant community and the quantitative characteristics of dominant plants and leaf functional traits were analyzed. The results showed that with the increase of grazing intensity， the average height， total coverage and aboveground biomass of plant communities decreased significantly（P<0.05）. The density was the highest in MG treatment. The leaf functional traits of S.breviflora decreased with the increase of grazing intensity， but the leaf dry matter content of C.songorica increased significantly. The aboveground biomass of plant community was significantly positively correlated with the height of two dominant plants and negatively correlated with the density. The decrease of specific leaf area and the increase of leaf dry matter content of C.songorica inhibited the accumulation of aboveground biomass of plant community. Therefore， under moderate grazing， dominant plants adjusted leaf functional traits and population structure to maintain grassland productivity and ecosystem stability； heavy grazing led to the degradation of ecosystem function.

This study seeks to identify high-yield and high-quality silage maize varieties that are well-suited to the low-latitude plateau monsoon climate. The objective was to mitigate the imbalance between forage supply and livestock demand on the Yunnan-Guizhou Plateau， support the implementation of the ‘grain-to-feed’ policy， and ultimately to promote the sustainable development of regional grassland animal husbandry. This study analyzed 11 silage maize varieties based on their agronomic traits， yield， and nutritional composition， and conducted a comprehensive evaluation using the grey relational analysis method. The results indicated that ‘Heyu36’ had the highest dry weight per plant at 0.37 kg， followed by ‘Jingke932’ at 0.33 kg. ‘Quchen513’ achieved the highest fresh biomass of 187.7 t·hm^-2. ‘Xikang18’ contained the highest crude protein content at 8.11%， while ‘Quchen513’ exhibited the lowest neutral detergent fiber and acid detergent fiber contents at 40.88% and 17.47%， respectively， resulting in the highest relative feed value of 171.52. Grey relational analysis revealed that ‘Quchen513’ had the highest comprehensive evaluation score with a weighted relational degree of 0.5668， followed by ‘Datian1416’ at 0.5482 and ‘Heyu36’ at 0.5382. In summary， ‘Quchen513’， ‘Datian1416’， and ‘Heyu36’ demonstrated outstanding performance in terms of fresh grass yield， dry matter yield， crude protein content， and stay-green characteristics， making them suitable for widespread cultivation in low-latitude plateau monsoon regions.

To elucidate the variation patterns of glomalin-related soil protein （GRSP） and their underlying drivers during the degradation and restoration of alpine meadows， this study quantified key soil physicochemical properties， soil organic carbon （SOC）， easily extractable GRSP （E-GRSP）， and total GRSP （T-GRSP） in both the 0-10 cm and 10-20 cm soil layers. The relationships between these variables and potential driving factors were analyzed using Pearson correlation analysis and redundancy analysis. Results showed that in the 0-10 cm layer， SOC decreased significantly with grassland degradation （P<0.05）， and artificial restoration was more effective than natural regeneration in enhancing SOC levels. Both E-GRSP and T-GRSP in the 0-10 cm layer exhibited an initial decline followed by a subsequent increase during the processes of degradation and recovery （P<0.05）， whereas the ratios of E-GRSP/SOC and T-GRSP/SOC displayed an opposite trend. Pearson correlation analysis revealed a highly significant positive correlation （P<0.01） between T-GRSP， E-GRSP， and SOC across the 0-20 cm soil profile. Redundancy analysis indicated that SOC was the primary explanatory variable for variations in both GRSP content and GRSP/SOC ratios throughout the 0-20 cm soil depth. Collectively， these findings suggest that grassland restoration promotes the preservation of GRSP in alpine meadow soils， and increased GRSP content contributes to enhanced SOC accumulation， highlighting its crucial role in soil carbon sequestration and the stability of soil carbon pools. This study provides valuable insights into carbon sequestration mechanisms in grassland ecosystems， supports improvements in soil structure stability， facilitates soil quality assessment， and offers practical guidance for ecological restoration efforts.

In order to explore the effects of alkaline salt stress on the ascorbic acid-glutathione cycle（AsA-GSH） of mitochondria in the radicle and plumule of Bothriochloa ischaemum， this experiment used ‘Taihang’ Bothriochloa ischaemum as material， which was germinated in NaHCO₃ and Na₂CO₃ solutions with Na⁺ concentration of 0（CK）， 10 and 30 mmol·L^-1， and then changes in the activities of AsA-GSH enzymes and lipid peroxidation in their mitochondria of radicle and plumule were analyzed. The results showed that the activities of superoxide dismutase， catalase， glutathione peroxidase and monodehydroascorbate reductase in the mitochondria of radicle increased with the increase of Na⁺ concentration （0-30 mmol·L^-1）， but the opposite phenomenon was observed in the activities of glutathione sulfur transferase， ascorbate peroxidase and glutathione reductase. With the increase of Na⁺ concentration （0-30 mmol·L^-1）， the activities of superoxide dismutase， catalase and glutathione peroxidase in the mitochondria of plumule increased significantly （P<0.05）， but the activities of glutathione sulfur transferase， glutathione reductase and monodehydroascorbate reductase decreased significantly （P<0.05）. There were differences in the effects of type and concentration under alkaline salt on the AsA-GSH in radicle and plumule of Bothriochloa ischaemum， and the sensitivity of mitochondrial AsA-GSH in radicle of Bothriochloa ischaemum to alkaline salt stress was higher than that in plumule.

To investigate the responses of forage growth and grassland soil nutrients to nitrogen fertilizer application， and to promote forage yield enhancement and soil nutrient balance， this study conducted a meta-analysis of 62 selected publications comprising 629 valid data sets. The analysis examined the effects of nitrogen fertilizer application on forage growth and soil nutrients under varying meteorological conditions （climatic zones， mean annual rainfall and mean annual temperature）， soil conditions （alkali-hydrolyzable nitrogen （AN）， total nitrogen （TN）， and organic matter （OM））， as well as the amount of nitrogen fertilizer applied （low， medium， and high）. The results indicated that nitrogen fertilizer application significantly enhanced forage growth and improved soil nutrient status. Specifically， forage height and dry matter yield increased by 25.7% and 58.4%， respectively， while soil TN， AN， and OM contents increased by 21.8%， 19.3%， and 9.0%， respectively. Nitrogen fertilizer application in wet， low-temperature regions most effectively promoted forage growth， whereas nitrogen fertilizer application in wet， high-temperature regions was more conducive to enhancing soil nutrient availability. Nitrogen fertilizer application to nutrient-poor grasslands resulted in a more pronounced increase in forage dry matter yield， and even low rates of N addition produced substantial benefits. Our results demonstrate that nitrogen fertilizer addition exerts positive effects on both forage productivity and soil fertility， providing a scientific basis for grassland fertilization decision-making.

This study was conducted in a Stipa breviflora desert steppe in central-western Inner Mongolia. Based on a long-term （since 2004） fixed-site grazing control experiment platform， four gradients of grazing intensities were set up： ungrazed （Control check， CK）， lightly grazing （LG）， moderately grazing （MG）， and heavy grazing （HG）. Litter and soil samples （0-30 cm depth） were collected to systematically analyze the contents and stoichiometric ratio characteristics of carbon （C）， nitrogen （N）， and phosphorus （P）. The results showed that with increasing grazing intensity， the litter standing crop and its C， N， and P contents decreased significantly， reflecting a reduction in both the quantity and quality of litter. In contrast， the contents of C， N， and P in the soil did not change significantly as grazing intensity increased. However， under moderately and heavy grazing intensities， the coupling relationships among soil nutrients weakened， which indicated that overgrazing led to the “decoupling” of the plant-litter-soil system. This study demonstrates that litter is not only a direct target of grazing impacts but also a key link in the system’s nutrient cycling and feedback regulation. Long-term high-intensity grazing may weaken this regulatory role and exacerbate nutrient limitations. These findings provide important scientific insights for the in-depth understanding of nutrient cycling mechanisms in desert steppe ecosystems and the guidance of ecological restoration and management practices.

Grazing and topography are key factors influencing the structure and function of alpine shrub ecosystems， but their effects on shrub populations and communities remain unclear. For this purpose， this study explored the effects of topography （three types of slope positions） and grazing （three distances from livestock enclosure） on the dominant species of alpine shrubland Caragana jubata and the companion species Thalictrum alpinum in the Qilian Mountain Grassland Agricultural Demonstration Area. The results showed that： 1） The distance from livestock enclosure explained the plant height and height-to-crown ratio of the Caragana jubata as 45.10% and 46.80% （P<0.01）， and the plant height， height-to-crown ratio and density of the Thalictrum alpinum as 46.50%， 40.60%（P<0.01） and 55.30% （P<0.001）. The topography only affects the population coverage of the Caragana jubata， which can explain that the coverage of the Caragana jubata is 22.30% （P<0.05）. 2） The overlap degree of the ecological niches of the Caragana jubata and the Thalictrum alpinum is the lowest at a distance of 400 meters between the livestock enclosure and the highest at 1200 meters. 3） The plant height， crown breadth and density of the population of Thalictrum alpinum significantly affected the community coverage， with an interpretation rate of 35.3% （P<0.05）. The community coverage significantly affected the population density of Thalictrum alpinum， with an interpretation rate of 25.1%（P<0.01）. The plant height， density and importance value of the population of Caragana jubata significantly affected the community coverage， with an interpretation rate of 57.6%（P<0.01）. This study reveals the role of grazing and topography in influencing the shrub-herbaceous competitive balance in alpine shrublands by regulating population growth and its population-community relationship， providing a scientific basis for grazing in complex topography.

Studying the altitude distribution pattern and driving factors of plant community diversity in subalpine meadow is helpful to reveal the mechanism of plant community species coexistence and diversity maintenance under the background of coastal elevation gradient. In this study， the plant community in Gongnaisi mountain area was taken as the research object， and the distribution law of plant community diversity along the elevation gradient and environmental influencing factors were discussed to reveal the plant community construction mechanism in this area. The results showed that： （1） With increasing the altitude， Pielou index， Simpson index， Shannon-Wiener index， Functional Evenness Index （FEVE）， Functional Divergence Index （FDIS） and Rao’s second entropy index all showed a single-peak change pattern， and the system development structure changed from divergence to aggregation； （2） PD index was significantly positively correlated with species richness and Margalef index， and positively correlated with Pielou index and Rao second entropy index. In addition， except FDis， there was a positive correlation between species richness index and functional diversity index； （3） Community diversity was mainly affected by environmental factors such as soil organic matter， total nitrogen， pH， average annual temperature， average annual precipitation and soil moisture. The plant community diversity in Gongnaisi subalpine meadow changed regularly along the elevation gradient， and its distribution pattern was mainly driven by environmental factors such as soil organic matter， total nitrogen， pH， annual average temperature， soil moisture content and annual average precipitation.

Grasslands play a vital role in safeguarding ecological security and sustaining ecosystem functions. Xinjiang hosts some of China’s most abundant grassland resources. However， under the combined impacts of climate change and human activities， grassland degradation has become increasingly prominent in recent years. To comprehensively assess the current status and degree of ecological restoration in the Xinjiang “Grazing Withdrawal and Grassland Restoration” project areas， we evaluated ecosystem structure， ecosystem quality， and ecosystem services by integrating the InVEST and RUSLE models to quantify restoration outcomes. The results show that： （1） In terms of ecosystem quality， net primary productivity （NPP） increased from 190.96 g·m^-2·a^-1 in 2003 to 205.34 g·m^-2·a^-1 in 2021， and fractional vegetation cover （FVC） continued to rise， with improving areas accounting for 69.78% of the total areas. （2） Regarding ecosystem services， water conservation increased from 98.2 mm during 2003-2015 to 121.1 mm during 2015-2021. Soil retention increased from 273.74 to 283.61 t·hm^-2， while windbreak and sand-fixation capacity changed from 2.82 to 3.62 t·hm^-2. （3） The ecological restoration index （ERI） indicated that high-restoration areas （ERI>0.5） accounted for 19.08% of the study areas， whereas low-restoration areas （ERI≤0.2） represented only 0.02%. These findings provide quantitative evidence to support ecological protection and management in the project areas， facilitating zoned， graded， and differentiated ecological restoration strategies.

To investigate the effects of grazing and topography on alpine shrub populations， in this study the effects of topography and grazing on population growth， inter-species relationships in alpine scrub in the Qilian Mountains were analyzed by using the populations of Potentilla anserina and Poa subfastigiata as the research objects， through setting up three kinds of terrain， namely， valley， shady slopes， and sunny slopes and five different distances from livestock pens for each terrain type as grazing plots. The results showed that grazing and topography jointly regulated the growth of two plant populations. The increase in grazing pressure gradient （reduced distance from the livestock pens） inhibited the vertical （plant height） and horizontal （crown width） growth of the two species， and increased the population density and vegetation cover. The valley was characterized by a balance of water and heat resources， and the two species coexisted in the highest density， with shady slope has better humidity conditions and stable water supply， which was conducive to the growth and reproduction of moisture-loving Potentilla anserina. The sunny slope had ample sunlight and suitable thermal conditions， favoring the dominance of Poa subfastigiata in their ecological niche. The topography indirectly influenced the competition of the populations by altering the heterogeneity of microhabitats， while grazing directly influenced the competition through trampling. Topography indirectly affected population competition by altering microhabitat heterogeneity， grazing directly affects population dynamics through trampling and foraging. Topography and grazing influenced the competitive landscape of moisture-loving and drought-tolerant species， thereby affecting their status in the community. This study quantified the pathways of topography and grazing on the growth and interspecific relationships of alpine shrub populations， which can provide a scientific basis for the sustainable utilization of the alpine ecological barriers.

To advance the application of near-infrared （NIR） spectroscopy in assessing the quality of mulberry （Morus alba L.） silage， a total of 105 silage samples were collected. Interval Partial Least Squares （iPLS） was employed to extract informative spectral intervals， and rapid NIR prediction models were subsequently developed using Partial Least Squares （PLS）. The results indicated that the models for crude protein， acid detergent fiber， neutral detergent fiber， and pH exhibited the best performance and were suitable for practical prediction （R²cv， R²p>0.8； RPDcv， RPDp>2.5）. Models for dry matter， lactic acid， and condensed tannins demonstrated moderate performance and were adequate for approximate estimation （2<RPDcv<2.5； 2<RPDp<2.5）. In contrast， the model for hydrolyzable tannins required further refinement （RPDp<2）. Collectively， these findings suggest that models constructed based on characteristic spectral intervals offer enhanced stability and predictive accuracy. This approach provides a theoretical basis and technical support for the efficient production and utilization of mulberry silage， while also offering valuable insights for the development of NIR analytical instrumentation.

This study aimed to identify the optimal intercropping ratio of sweet sorghum （Sorghum bicolor） and sesbania （Sesbania cannabina） in the Chengdu Plain region and to clarify its effects on forage productivity and interspecific interactions. Five intercropping ratios （3∶1， 2∶1， 1∶1， 1∶2 and 1∶3； sweet sorghum ： sesbania） were established， with monocultures as controls. Agronomic traits， forage yield and nutritional quality were evaluated to assess the overall performance of the intercropping system. The results showed that intercropping significantly reduced plant height and stem diameter of both species. However， the nutritional quality of the mixed forage was significantly improved compared to sweet sorghum monoculture. Crude protein， total digestible nutrients and comprehensive quality indicators increased with the increas of sesbania proportion. Sweet sorghum monoculture produced the highest fresh and dry matter yields， while the 3∶1 intercropping ratio achieved the highest yield among the intercropping treatments. Interspecific interaction analysis indicated a facilitative effect when the sowing ratio exceeded 1∶1， whereas sesbania inhibited sweet sorghum growth at lower ratios. Based on TOPSIS and membership function evaluation， the optimal sowing ratio in the Chengdu Plain was determined to be 2∶1， corresponding to 14.67 kg·hm^-2 of sweet sorghum and 30.00 kg·hm^-2 of sesbania. These findings provide a scientific basis for optimizing the sweet sorghum–sesbania intercropping system in the Chengdu Plain.

This study took Medicago sativa as the research object to explore the impacts of irrigation and biochar application on the actual production benefits of Medicago sativa from the perspective of nutritional quality and economic benefits. Four irrigation gradients （W₁ reduction of 30%： 450 mm， W₂ reduction of 15%： 550 mm， W₃ conventional irrigation gradient ： 650 mm， W₄ increment of 15%： 750 mm） and two biochar application levels （C₀：0 t·ha^-1，C₂：20 t·ha^-1） were set to determine the nutrient quality and annual hay yield of Medicago sativa and screen the best irrigation amount and biochar application amount. The results showed that under the condition of biochar application， the crude protein content of Medicago sativa showed an increasing trend， the neutral detergent fiber was significantly lower than that under C₀ treatment， and the dry matter intake rate and relative feeding value were significantly improved. The annual yield in W₂C₂ treatment was significantly higher than that in W₂C₀ treatment， superior to other treatments， and the annual net profit was the best， 22 422.93 CNY·ha^-1， which was 2148.53 CNY·ha^-1 higher than W₃C₀. Comprehensive evaluation showed that W₂C₂ treatment was the optimal irrigation and biochar application scheme to achieve the synergistic improvement of Medicago sativa yield， quality and economic benefits.

In this study， a pot experiment with four addition ratios （0%， 20%， 40%， and 60%） of Corncob Fungus Chaff （CFC） was carried out to investigate their effects on seed germination， growth characteristics， photosynthetic traits， and saline-alkali soil properties of Elymus Nutans， and to identify the optimal addition ratio. The results showed that the addition of CFC significantly affected the growth of E. Nutans and soil properties （P<0.05）： the 40% addition ratio yielded the optimal effects， with its germination rate， germination potential， plant height， leaf area， dry matter accumulation， and photosynthetic efficiency being significantly superior to those of the other treatments； the 20% addition ratio significantly enhanced the net photosynthetic rate and stomatal conductance of E.nutans； the 60% addition ratio reduced soil pH， salinity， and bulk density by 4.71%， 30.00%， and 54.81% compared with the control， respectively， while increasing soil water content and porosity by 31.79% and 26.07%， respectively. Correlation analysis indicated that soil pH and salinity were significantly positively correlated with seed germination rate， and soil water content and porosity were significantly positively correlated with dry matter accumulation. In summary， the 40% CFC addition ratio is most suitable for the germination and seedling growth of E.nutans， and can effectively improve the physical properties of saline-alkali soil.

In order to explore the effects of moss crust on the growth of common grass and soil properties in alpine meadow， Elymus breviaristatus was used as a material. And the effects of moss inoculation on the growth and soil properties of E. breviaristatus were studied under indoor pot conditions with different moss inoculation rates （10 g·pot^-1， 15 g·pot^-1， 20 g·pot^-1 and no moss inoculation as a control）. The results showed that the inoculation of moss could promote the germination and growth of the plant. Under the condition of 10 g·pot^-1 inoculation， the germination rate， plant height， aboveground and underground biomass， and relative water content of plant were increased by 32.0%， 25.1%， 93.1%， 135.4% and 37.4%， respectively. The contents of soluble organic carbon， available nitrogen and microbial biomass carbon and nitrogen in soil increased to different degrees after moss inoculation. The activities of urease， sucrase， α-1， 4-glucosidase， β-1， 4-glucosidase， cellobiohydrolase and β-1， 4-xylosidase in soil increased by 69.2%， 372.5%， 197.2%， 110.1%， 44.2% and 105.6%， respectively. The effect was particularly obvious under the treatment of 15 g·pot^-1 inoculation. The correlation analysis showed that there was a significant correlation between the growth index and soil properties， and moss inoculation affected the growth of the plant by changing soil properties. Therefore， in the restoration of degraded alpine meadow， it can be considered to inoculate an appropriate amount of moss to improve soil fertility and to promote vegetation recovery， which provides a theoretical basis for the near-natural restoration measures of alpine meadow using moss.

To explore the effects of nitrogen application and sowing density interaction on the seed yield of ‘Qingyan No.2’ oat （Avena sativa ‘Qingyan No.2’） in the high-altitude area， the optimal planting nitrogen amount and sowing density suitable for the production of ‘Qingyan No.2’ in Huangzhong and its surrounding areas were investigated. This experiment adopted a two-factor randomized block design. Four nitrogen application levels of 0， 45， 90 and 135 kg·hm^-2 （denoted as N₀， N₁， N₂ and N₃） were set， and three sowing densities of 100， 170 and 240 kg·hm^-2 （denoted as S₁， S₂ and S₃） were established. The results showed that the effects of nitrogen application amount， sowing density， and their interaction on agronomic traits and seed yield all reached extremely significant （P<0.01） or significant （P<0.05） levels. Agronomic traits changed significantly with nitrogen application amount and sowing density. The length of the spike， the number of small florets on the main spike， the number of grains on the main spike， the grain weight per spike， and the hundred-grain weight all increased first and then decreased with the increase of nitrogen application amount， and decreased with the increase of sowing density. Seed yield increased first and then decreased with the increase of nitrogen application amount and sowing density， reaching the peak at a nitrogen application amount of 90 kg·hm^-2 and a sowing density of 100 kg·hm^-2. Pearson correlation analysis indicated that seed yield was significantly positively correlated with spike length， the number of small florets on the main spike， the number of grains on the main spike， the grain weight per spike， and the hundred-grain weight. TOPSIS-multi-criteria decision-making model analysis indicated that at a nitrogen application amount of 90 kg·hm^-2 and a sowing density of 100 kg·hm^-2 were the optimal nitrogen application amount and sowing density for ‘Qingyan No.2’ seed production in the study area and similar high-altitude areas.

To explore the effects of different intercropping patterns of silage corn （Zea mays L.） and sweet sorghum （Sorghum bicolor） / grain corn （Z. mays） on forage yield， quality， and interspecies relationships， and to identify the optimal intercropping configuration， this experiment used silage corn （S）， sweet sorghum （T）， and grain corn （M） as controls， setting up six intercropping patterns： S₄T₂ （4 rows of silage corn∶2 rows of sweet sorghum）； S₃T₃ （3 rows of silage corn∶3 rows of sweet sorghum）； S₂T₄ （2 rows of silage corn： 4 rows of sweet sorghum）； S₄M₂ （4 rows of silage corn∶2 rows of grain corn）； S₃M₃ （3 rows of silage corn∶3 rows of grain corn）； S₂M₄ （2 rows of silage corn∶4 rows of grain corn）. The results indicated that intercropping significantly affected the agronomic traits of the forage crops compared to sole cropping （P<0.05）. The fresh grass yield of the S₃T₃ treatment was the highest， reaching 107.8 t·hm^-2； the S₃M₃ treatment exhibited the highest yields of hay， crude protein yield， and crude protein content， measuring 36.3 t·hm^-2， 3.5 t·hm^-2， and 9.6%， respectively， an increase of 17.3%， 14.6%， and 58.2% compared to sole silage corn. Intercropping significantly improved the Land Equivalent Ratio （LER=1.1~1.4）， indicating a yield advantage in the system. Notably， S₂T₄， S₃T₃， S₂M₄， and S₃M₃ treatments demonstrated stronger aggressivity and competitive ratio （Aggressivity， A>0； Competitive ratio， CR>1） for silage corn. Comprehensive analysis revealed that the intercropping of 3 rows of silage corn with 3 rows of sweet sorghum （S₃T₃） was the optimal pattern for effectively enhancing crop yield and quality.

To investigate the effects of mixing alfalfa and rapeseed straw in different ratios on the nutritional and fermentation quality of silage， a study was conducted using alfalfa at the early flowering stage and mature rapeseed straw as raw materials. The materials were mixed in the following ratios：10∶0 （T1），8∶2 （T2），7∶3 （T3），6∶4 （T4），5∶5 （T5），4∶6 （T6），3∶7 （T7），2∶8 （T8），and 0∶10 （T9）. The silage bags were opened after 5，10，20，40， and 60 days of fermentation. Silage quality was comprehensively evaluated using sensory evaluation and the V-Score system， and its nutritional and fermentation characteristics were analyzed. The results showed that alfalfa alone （T1） exhibited poor fermentation， while the addition of rapeseed straw increased lactic acid content， and decreased pH and ammonia-nitrogen/total nitrogen （NH₃-N/TN）. Silage made from rapeseed straw alone （T9） had low nutritional value. As the proportion of alfalfa increased， the contents of crude protein and crude fat increased， while the neutral detergent fiber （NDF） and acid detergent fiber （ADF） contents decreased. Prolonging the ensiling time led to decreasing trends in dry matter， crude protein， crude fat， NDF， and ADF contents across all treatments. Both sensory evaluation and V-Score indicated the highest scores at 40 day silage. At this time point， all treatments showed lower pH values. The optimal mixed silage effect was achieved with the alfalfa to rapeseed straw ratio of 6∶4 and the fermentation period of 40 day. These findings provide a theoretical basis for determining the best mixing ratio and fermentation duration for alfalfa and rapeseed straw silage.