Ecological restoration is an important part of mining operations. The aim of this study was to analyze the plant community at the initial stage of ecological restoration in the gangue yard at the Ningdong coal base， with an overall goal to establish a stable artificial vegetation ecosystem on the coal gangue hills. The aboveground vegetation was sampled using a quadrat method， and the importance values of shrubs and grasses were calculated. The niche width， niche similarity， niche overlap， and variance ratio were calculated. Chi-squared and Spearman’s correlation analyses were used to explore the interspecific associations among， and correlations between， dominant species in the plant community in the mining area. The results showed that there were 44 species of shrubs and grasses in the study area， belonging to nine families and 36 genera. The main plant families were Poaceae， Fabaceae， Asteraceae， and Amaranthaceae. The niche width and importance value rankings of shrub species were not completely consistent， but the overall trend was consistent， with Oxytropis aciphylla and Caragana korshinskii being the dominant species. The niche width and importance value rankings of herbaceous species were consistent， with Grubovia dasyphylla and Medicago sativa being the dominant species. The variance ratio of the overall association between shrubs and herbaceous plants was greater than one. There was a significant positive association among shrub species， whereas the association among herbaceous species was not significant. In conclusion， the plant community in the ecological restoration area is in the early or middle stage of succession， with weak interspecific competition. When designing an ecological restoration strategy for the Ningdong coal base， plants positively associated with dominant species should be selected to form a stable plant community structure， thereby improving the efficiency of ecological restoration in this mining area.

This research investigated the effects of slope categories defined by slope aspect （shady， semi-shady and semi-sunny slope） and slope position （upper， middle and lower position） on the diversity of alpine shrub community in Qilian Mountains， so as to provide a scientific basis for accurate zoning and management or utilization of alpine shrub vegetation in this region. For the above-mentioned slope categories， the community composition and structure， light intensity， and soil physicochemical characteristics of alpine shrubland were systematically measured， a piecewise structural equation model was used to analyze processes influencing shrub community diversity， and path coefficients of slope aspect and position effects were determined. The results showed that the height， cover， aboveground and belowground biomass of herb and shrub were highest at the lower slope position （P<0.05）， while the β diversity was highest on the shady slope and lowest on semi-sunny slope （P<0.05）. Shannon-Wiener diversity index， richness index and Pielou evenness index of herb， shrub and community decreased from the lower slope position to upper slope position. The light intensity and soil physicochemical characteristics were significantly higher at the lower slope position than at the upper slope position. The piecewise structural equation model showed that slope aspect and slope position affected the diversity of herbs mainly through factors such as light intensity and soil organic matter content， while they affected the diversity of shrubs mainly through factors such as light intensity， soil water content and soil available nitrogen content. For the smaller scale topographic variation investigated， slope aspect and slope position affected the distribution pattern of plant community diversity mainly through factors such as light intensity， soil water content， soil organic matter content and available nitrogen content. Therefore， when collecting data for precise zoning and to plan ecological restoration of degraded grassland in alpine shrubland， it is important to consider the change of plant community microhabitat conditions and the variation of vegetation distribution patterns which are induced by slope aspects and positions arising from small-scale topographic variation.

This study was conducted in Hutubi and Manas Counties of Changji Hui Autonomous Prefecture in Xinjiang Uygur Autonomous Region， and investigated how soil microbial carbon source utilization patterns in sagebrush desert grassland changed in response to fencing enclosure. Field investigation and laboratory analyses were combined to measure and analyze the characteristics of soil microbial carbon source utilization both inside and outside the enclosure. Factors driving responses were examined based on vegetation characteristics and physicochemical properties of the soil. The results showed： 1） After fencing enclosure， the aboveground biomass （AGB） and litter biomass （LB） of sagebrush desert grassland were significantly increased by 142.53%-250.05% and 135.68%-259.84% （P<0.05）， respectively. The contents of soil organic carbon （SOC）， total nitrogen （TN） and total phosphorus （TP） in 0-10 cm and 30-50 cm soil layers were increased by 4.88%-35.33%， 10.48%-46.58% and 4.48%-21.88%， respectively， and the contents of total nitrogen and total phosphorus also showed significant changes （P<0.05）. 2） The utilization by soil microbial communities of six categories of carbon source increased significantly after enclosure， and the behavior of surface and deeper soil layers was consistent （P>0.05）. 3） After enclosure， the McIntosh index and Shannon-Wiener index increased by 14.72%-47.01% and 36.29%-74.76%， respectively， while the Simpson index decreased by 1.09%-7.53% （P>0.05）， except in the 0-10 cm soil horizon in Hutubi County. Enclosure improved the microbial diversity of sagebrush desert grassland. 4） Through redundancy analysis， it was found that the main driving factors of microbial carbon source in the 0-10 cm soil layer were SOC and litter biomass， while the driving factors in the 30-50 cm soil layer were soil TP and aboveground biomass. In conclusion， the enclosure by fencing in sagebrush desert grassland was found to enhance the metabolic activity of soil microorganisms， thereby fostering nutrient cycling and transformation within the ecosystem， specifically in terms of SOC， TN and TP. Furthermore， this practice led to an improvement in microbial diversity， ultimately promoting the restoration of degraded grassland and enhancing the overall health and resilience of the sagebrush desert grassland ecosystem.

Vegetation coverage on the Qinghai-Tibet Plateau is a crucial metric for ecological studies and environmental monitoring. Traditional methods to detect vegetation coverage are effective in regions with simple terrains and concentrated vegetation. However， in complex terrains， issues such as high costs， restricted survey areas， and extended time intervals reduce the accuracy of the results obtained using such traditional methods. In recent years， rapid advancements in computer vision and deep learning have created new opportunities for precise vegetation extraction in the complex terrains of the Qinghai-Tibet Plateau. Here， we introduce a two-stage vegetation extraction algorithm that integrates YOLOv5 and an improved DeeplabV3+. The algorithm utilizes a vegetation detection model based on YOLOv5 to minimize background interference during the second stage of vegetation segmentation； and a newly designed DeeplabV3+ semantic segmentation model for accurate vegetation segmentation and extraction. The improved model incorporates the lightweight backbone network MobileNetV2， optimizes the dilated convolution parameters of the ASPP module， and integrates EMA and CloAttention mechanisms. The experimental results on the unmanned aerial vehicle dataset of the Qinghai-Tibet Plateau demonstrate that the algorithm attains an intersection over union （IoU） of 90.40% and a pixel accuracy （PA） of 96.32%， significantly outperforming other current technologies and greatly reducing the model’s parameters. Under various environmental conditions， the algorithm exhibits high-precision capabilities for vegetation extraction， offering effective technical support for the rapid and precise measurement of vegetation cover on the Qinghai-Tibet Plateau.

Wave erosion is one of the main ecological and environmental problems in the water-level fluctuation zone of the Three Gorges Reservoir area. As single factors， the presence of plants and gravel can effectively control wave erosion. However， it is unknown how the combination of these control measures affects wave erosion. Therefore， wave experiments were conducted under three levels of Cynodon dactylon cover （20%-30%， 40%-50%， 60%-70%） and nine different gravel conditions （three thicknesses of gravel cover， 20， 40 and 60 mm； and three gravel particle sizes， 5-10， 10-15， and 15-20 mm）. The bare slope without gravel and plant cover served as the control check （CK）. The effects of plant cover and gravel as single and combined factors on wave erosion were explored by measuring the wave pressure and wave erosion rate in each treatment. The results indicated that gravel decreased the wave pressure by 26.49%-86.52% and the wave erosion rate by 8.70%-73.91%， compared with values for the CK. The wave pressure and wave erosion rate decreased as the gravel particle size decreased and as the gravel cover increased. The presence of C. dactylon decreased the wave pressure by 4.10%-46.36% and the wave erosion rate by 19.56%-77.17%， compared with values for the CK. The wave pressure and wave erosion rate decreased with increasing cover of C. dactylon. The wave pressure and wave erosion rate decreased by 28.95%-94.74% and 28.20%-80.43%， respectively， under the combined effects of gravel and C. dactylon. Also， under the combined effects， the wave pressure and wave erosion rate increased with increasing gravel particle size， and decreased with increasing gravel thickness and cover of C. dactylon. Compared with the single effect， further reductions of wave pressure and wave erosion rate under the combined effects were attributed to the synergistic effects of plant and gravel cover. The largest reductions in wave pressure and wave erosion rate were obtained with a gravel particle size of 5-10 mm， gravel cover thickness of 60 mm， and C. dactylon cover of 60%-70%. Multivariate analysis of variance showed that the combined effect of gravel and C. dactylon cover synergistically reduced the wave pressure and wave erosion rate. The factors were ranked， from highest degree of influence on wave pressure to lowest， as follows： gravel cover thickness>gravel particle size>plantcover； and from highest degree of influence on wave erosion rate to lowest， as follows： plantcover>gravel cover thickness>gravel particle size. Our results show that gravel and vegetation work synergistically to reduce wave energy and erosion， and can be used as a sustainable and ecologically friendly treatment to control wave erosion on sloping banks. These findings provide guidance and reference data for the ecological management and ecological reconstruction of the water-level fluctuation zone in water reservoirs.

Natural precipitation is the only water source in the semi-arid loess region. This research investigated the characteristics of soil water infiltration following precipitation after replanting deep-rooted， perennial plants in soil with severely depleted moisture levels in the hilly areas of the Loess Plateau. Specifically， the research simulated the cultivation of Medicago sativa， using large-scale soil columns （lysimeters） at the Wangwa Soil and Water Conservation Experiment Station in southern Ningxia. The simulation experiment was based on actual rainfall data from March to October in 2022-2023. The results indicated that： 1） Only 41.67% of all precipitation events resulted in soil water infiltration. The ratio of infiltration to precipitation varied with rainfall intensity： in light rain， moderate rain， heavy rain and torrential rain the infiltration was， respectively， 15.89%， 35.63%， 52.20% and 61.50% of the total precipitation. Infiltration amounts thus showed an increasing trend with increasing precipitation. 2） Precipitation infiltrating to depths of less than 30 cm， to depths of 30-80 cm， and to depths greater than 80 cm， accounted for， respectively， 76.04%， 18.75% and 5.21% of the total precipitation. 3） With respect to the issue of deep soil water depletion， alfalfa cultivation led to a trend of soil water increase in soil water measured monthly for one year old plants， while for two year old plants， soil water measured monthly showed a decreasing trend. The monthly infiltration depth （Z_m） increased with increasing monthly precipitation （P_m） as a quadratic function： Z_m=-0.0101P_m²+3.9426P_m （R²=0.9895）. The study provides data on deep soil water status， useful for planning the replanting and sustainable development of deep-rooted， perennial plants in areas on the Loess Plateau with severely dried deeper soil horizons.

The aim of this study was to clarify the effects of exogenous melatonin and ethylene in combination on the salt tolerance of alfalfa （Medicago sativa）. An experiment was conducted in which the alfalfa cultivar ‘Zhongmu No.1’ was treated with exogenous melatonin， ethephon， and melatonin+ethephon， and then the growth and physiological characteristics of alfalfa seedlings under salt stress were determined. Exogenous application of a range of concentrations of melatonin （0.01， 0.02， 0.05， 0.10 mmol·L^-1） and ethephon （0.05， 0.15， 0.25， 0.50 mmol·L^-1） as foliar sprays alleviated the reduction in the growth of alfalfa seedlings caused by salt stress （250 mmol·L^-1 NaCl）. The strongest alleviation effects were in the 0.05 mmol·L^-1 melatonin treatment and the 0.15 mmol·L^-1 ethephon treatment. The application of melatonin and ethephon alone to alfalfa seedlings under salt stress resulted in significantly increased plant height， leaf area， fresh weight， chlorophyll content， and carotenoid content of alfalfa seedlings， and significantly decreased relative electrical conductivity. We conducted further experiments using the above optimal treatment concentrations of melatonin and ethephon. Compared with the control group， salt-stressed alfalfa seedlings showed significantly inhibited growth. Compared with salt-stressed seedlings， those treated with exogenous hormones showed improved growth， especially those treated with melatonin and ethephon simultaneously. Compared with salt-stressed alfalfa seedlings， the seedlings treated with melatonin and ethephon simultaneously showed increased plant height， leaf area， and fresh weight （by 54.1%， 76.8%， and 32.1%， respectively）； increased tissue water content and chlorophyll content （by 46.2% and 47.8%， respectively）； decreased relative conductivity and malondialdehyde content （by 23.5% and 39.7%， respectively）； decreased hydrogen peroxide and superoxide anion contents （by 42.7% and 63.8%， respectively）； increased activities of superoxide dismutase， peroxidase， catalase， and ascorbate peroxidase （by 54.1%， 54.1%， 59.1%， and 62.0%， respectively）； higher reduced glutathione content （by 32.8%）； increased proline and soluble sugar contents （by 42.2% and 27.2%）， a higher potassium ion∶sodium ion （by 217.5%）， and increased contents of endogenous melatonin and ethylene （by 60.0% and 10.6%， respectively）. These comprehensive analyses showed that exogenous application of melatonin and ethylene significantly reduced the levels of membrane peroxidation and reactive oxygen species in alfalfa， increased the activity of antioxidant enzymes and the contents of osmoregulatory substances， regulated the ionic balance， and increased the contents of endogenous hormones. Together， these changes improved the salt tolerance of alfalfa seedlings. Thus， melatonin and ethylene treatments can improve the growth of alfalfa seedlings under salt stress.

Irrigation and fertilization are important measures to improve alfalfa seed productivity. Understanding the mechanisms of seed yield formation will be helpful for optimizing water and fertilizer management. The relationships between leaf nutrient characteristics at the reproductive growth stage and the seed yield of alfalfa remain unclear. We investigated leaf nutrient contents and nutrient resorption efficiencies in alfalfa plants at the reproductive stage， and their relationships with seed yield， under different irrigation and nitrogen （N） fertilization conditions. Six irrigation treatments were set up comprising differing rates of irrigation at re-greening in spring， budding and podding growth stages. The irrigation treatments were： full irrigation （450， 150 mm at each irrigation， W₁）； mild water deficit （360， 120 mm at each irrigation， W₂） and moderate water deficit （270， 90 mm at each irrigation， W₃）； 300 mm irrigation allocated 150， 75 and 75 mm， respectively， at re-greening， budding and podding stages （W₄）； 300 mm irrigation allocated 75， 150 and 75 mm， respectively， at re-greening， budding and podding stages （W₅）； and 300 mm irrigation allocated 75， 75 and 150 mm， respectively， at re-greening， budding and podding stages （W₆）. The N fertilization treatments were 10 kg·ha^-1 （N₁）^{or 40 kg·ha-1 （N₂） applied at re-greening. N and P contents of green and senescent leaves were measured at budding， podding stages and at crop maturity to allow calculation of N and P resorption. It was found that： 1） With decreasing irrigation and advancing growth stages， there were decreases in the N and phosphorus （P） contents in green leaves at the reproductive growth stage. The nutrient contents of green leaves were not lower in W₄ and W₅ than in W₃ or even W₂. The nutrient contents in green leaves at the budding and podding stages were significantly higher in N₂ than in N₁. The N and P contents in senesced leaves at the reproductive growth stage increased as irrigation decreased and growth stages advanced. The N content of senesced leaves at the budding stage was lower in W₄ and W₅ than in W₁-W₃， but the N content of senesced leaves at the podding and maturity stages was higher in W₄ and W₅ than in W₁ and even W₂. The N content of senesced leaves at the maturity stage was higher in N₂ than in N₁， and the P content at the podding stage was higher. 2） The leaf nutrient resorption efficiency during the reproductive growth stage decreased with decreasing irrigation and advancing growth stages. Nutrient resorption efficiency at the budding stage was higher in W₄ and W₅ than in W₁-W₃， but that at the podding and maturity stages was similar in W₄， W₅， and W₃. The N resorption efficiency at the budding stage was higher in N₂ than in N₁， but higher in N₁ than in N₂ at the other stages. The P resorption efficiency was higher in N₂ than in N₁ during the whole reproductive growth period. 3） The seed yield was numerically highest in W₂ and_{numerically lowest in W3 withother treatments intermediate. Hence W2 separated statistically only from W3 and W4， while W3 separated statistically only from W1 and W2. The seed yield under deficit irrigation was not lower than that in W1 or even W2. The seed yield was higher in N2 than in N1. 4） Seed yield was positively correlated with the N and P contents of green leaves and with nutrient resorption efficiencies at the podding stage， and negatively correlated with the nutrient contents of senesced leaves. Therefore， irrigation and N fertilization significantly affected the leaf nutrient contents during the reproductive growth stage of alfalfa， and their effects varied depending the growth stage. Nutrient resorption at the podding stage increased the supply of nutrients for seed formation. In conclusion， the highest alfalfa seed yield was obtained when N fertilizer was applied at 40 kg·ha-1 under slight water deficit during the whole growth period， or under deficit irrigation at the re-greening and budding stages plus full irrigation at the podding stage.}}

In order to explore the continuous cropping obstacle effect of Codonopsis pilosula var. modesta and its mechanism， pot experiments were conducted in the soil of normal crop （CK）， and continuous cropping 1 year （CC₁）， continuous cropping 2 years （CC₂） and continuous cropping 3 years （CC₃） as experimental objects. The effects of continuous cropping on the growth， antioxidant enzyme system and chlorophyll of C. pilosula var. modesta were evaluated， and the types and levels of autotoxic substances in the soil of different continuous cropping years were analyzed by gas chromatography-mass spectrometry （GC-MS）. The results showed that continuous cropping had an inhibitory effect on the growth of C. pilosula var. modesta at the seedling stage， flowering stage， peak growth stage and harvest stage， and the effect gradually strengthened with increase in the number of continuous cropping years. In the same continuous cropping years， with the advancement of growth process， the activities of catalase （CAT） and superoxide dismutase （SOD） in leaves initially increased and then decreased， and the activities of peroxidase （POD） initially decreased and then increased and then decreased again， but at the same growth stage， the activities of the three antioxidant enzymes all decreased year by year， and but the levels of malondialdehyde （MDA）， proline （Pro）， soluble sugar and the relative conductivity all increased year by year. The results of GC-MS showed that 5， 17， 13 and 4 chemical substances were identified from CK， CC₁， CC₂ and CC₃， respectively， including di-2-ethylhexyl phthalate， dibutyl phthalate， ethyl propionate and oleamide， among which di-2-ethylhexyl phthalate was found in all treatments with relatively high levels. It can be seen that continuous cropping can inhibit the growth of C. pilosula var. modesta by disrupting the antioxidant enzyme system and reducing the leaf chlorophyll content， resulting in continuous cropping disorders. The autotoxicity under continuous cropping is one of the main causes for continuous cropping disorders in C. pilosula var. modesta.

Precision water and fertilizer management in farmland when water is scarce needs to take account of the development patterns of the crop root system within the soil and over time. Here， Phaseolus vulgaris root biomass， length， surface area， volume and diameter was monitored in two differing light loamy or sandy chestnut soil fields at different growth stages using stratified excavation to extract root samples and image analysis techniques to quantify root parameters. The results showed that the root biomass of P. vulgaris in the two fields was similar， and roughly divided into three stages： slow growth， linear growth and slow decline. The linear growth period was from the initial flowering stage to the full pod stage. At this stage， the daily growth rates of fresh and dry weight of P. vulgaris root systems were 2.46 and 0.24 g·2 plants^-1 in light loamy chestnut soil fields， while they were 1.79 and 0.20 g·2 plants^-1 in sandy chestnut soil fields. The root system parameters， such as root length， surface area and volume， were all positively correlated with root fresh and dry weight. From a vertical distribution perspective， the root distribution of P. vulgaris in sandy chestnut soil was shallower than in loamy chestnut soil. In the sandy soil， more than 82.68% of the roots were distributed in the 0-30 cm soil horizon. In the light loamy soil， more than 86.24% of the roots were distributed in the 0-60 cm soil horizon， after the initial pod stage. From a lateral distribution perspective， over 77% of the P. vulgaris root systems in light loamy chestnut soil were distributed within a 30 cm radius on both sides of the plant during the entire growth period， while the proportion of root systems in sandy chestnut soil showed a decreasing trend with growth development， and decreased to over 66% at the end of podding. The contour map of the root systems showed that， P. vulgaris roots in light loamy chestnut soil exhibited narrow and deep placement， while in sandy chestnut soil placement was wide and shallow. This research lays a foundation for development of innovative and efficient water and fertilizer utilization technology for P. vulgaris in the Bashang area.

The root hemiparasite Pedicularis kansuensis derives nutrients from its host， Stipa purpurea， through structures known as haustoria， and this suppresses the growth of S. purpurea. Previous studies have shown that Epichlo? endophytes， microorganisms that form a symbiotic relationship with their host， are able to ameliorate the damage to S. purpurea caused by the hemiparasite P. kansuensis. The potential mechanism of this effect may be that Epichlo? positively regulates the root morphology of its host infected with the hemiparasite. In this study， we conducted a pot experiment to compare the root morphology between endophyte-infected （E+） and endophyte-free （E-） S. purpurea parasitized by P. kansuensis at different densities. Our results indicate that parasitism by P. kansuensis decreased both the shoot and root biomass of S. purpurea， and resulted in substantially decreased values of all the measured root morphological traits. The values of biomass and root morphological traits of S. purpurea sharply decreased with increasing density of P. kansuensis. The values of biomass and root morphological parameters of S. purpurea parasitized by P. kansuensis were higher in the E+ group than in the E- group. A structural equation model indicated that as the total length， surface area， and topological index of S. purpurea roots decreased， the biomass of S. purpurea decreased. The inhibitory effect of P. kansuensis on the growth of S. purpurea was positively related to the density of P. kansuensis. By contrast， the presence of the Epichlo? endophyte facilitated the accumulation of biomass of S. purpurea parasitized by P. kansuensis through altered root morphological traits including root total length and surface area， and the number of externally connected grass roots. In conclusion， Epichlo? endophytes are able to alleviate stress imposed by a hemiparasite upon P. kansuensis by facilitating change in its root morphological traits. Our findings reveal new information about the mutualistic relationship between Epichlo? endophytes and their hosts， and demonstrate that the introduction of the Epichlo? symbiont isan effective biological method to control hemiparasitic weeds.

Endophytic fungi with the capacity to enhance plant growth， bolster plant stress tolerance， and modulate the composition of plant rhizosphere microbial communities offer significant implications for research and development of crop growth promotants. In a plot experiment， two endophytic fungus， Trichoderma rossicum and Floccularia luteovirens were applied. To assess the growth promoting effects of these endophytic fungi on Avena sativa， a range of indicators were measured， encompassing growth characteristics， physiological and biochemical parameters， soil physical and chemical properties， and others. In addition， high-throughput sequencing technology was utilized to assess the influence of endophytic fungus soaking on the composition of A. sativa root endophytic fungal communities. It was found that the application of the two endophytic fungi noticeably enhanced the growth of A. sativa， with increase in plant height， root length， dry weight， fresh weight， and other parameters observed. Particularly noteworthy was the pronounced influence of T. rossicum on the growth traits of A. sativa， while F. luteovirens had the greatest effect on the yield of A. sativa. Additionally， endophytic fungi significantly influenced physiological traits of A. sativa （P<0.05）. For instance， compared to CK， the peroxidase activity was increased by 87.53%， and 86.03%， respectively， with T. rossicum and F. luteovirens seed soaking， while vitamin C content was increased by 5.56% and 58.11%. Conversely， proline and malondialdehyde levels were decreased， respectively by 64.62% and 54.82% with T. rossicum and by 72.85% and 63.85% with F. luteovirens seed soaking. Furthermore， the two endophytic fungi exerted distinct effects on soil physicochemical properties. Specifically， T. rossicum and F. luteovirens increased soil total phosphorus concentration， while F. luteovirens dramatically elevated soil organic carbon concentration. The high-throughput sequencing findings demonstrated that soaking endophytic fungi significantly influenced the diversity of endophytic fungi in the A. sativa rhizosphere. This was evidenced by increases in the Shannon index， Pielou index， and the number of unique OTUs of endophytic fungi in A. sativa roots， as well as changes in the community structure of endophytic fungi in the A. sativa roots. Additionally， a principal component analysis revealed that T. rossicum enhanced growth and diversified the variety of root endophytic fungi associated with A. sativa， whereas F. luteovirens enhanced productivity and bolstered stress tolerance of A. sativa. This study highlights the significant stimulatory impact of endophytic fungus soaking on the growth of A. sativa， enhancing its stress resistance， and altering the root endophytic fungal community. These findings pave the way for the utilization of F. luteovirens and T. rossicum as microbial fertilizers， thereby providing valuable fungal resources for the development of plant growth-promoting preparations in subsequent research.

The AP2/ERF transcription factors are plant-specific transcription factors. Among them， those in the DREB subfamily have been widely reported to improve plant resistance to abiotic stresses. To explore the roles of DREB family members in Lilium pumilum， we identified correlations between the transcript levels of DREB transcription factor genes and drought tolerance. We isolated the cDNA of the LpDREB9 gene from the roots of L. pumilum， and then conducted bioinformatics and subcellular localization analyses. This gene was then introduced into the model plant Nicotiana tabacum to elucidate its role in drought tolerance. The open reading frame （ORF） of LpDREB9 gene was 462 bp， encoding a protein of 153 amino acids with a relative molecular weight of 17.054 kDa， the fat index of 73.46， and a pI value of 4.89. It was an unstable and hydrophilic protein. Subsequent analysis revealed the nuclear localization of the LpDREB9 protein. In an alignment analysis， the LpDREB9 gene showed the closest evolutionary relationship with its homologs in Lilium regale. Seeds and seedlings of wild-type （WT） tobacco and transgenic tobacco expressing LpDREB9 were exposed to abscisic acid and drought stress. Phenotypic and physiological parameters of the seedlings after natural drought stress and subsequent rehydration were determined. The results indicated that the LpDREB9 gene enhanced drought tolerance in transgenic tobacco plants， particularly under prolonged drought stress. The activities of superoxide dismutase， peroxidase， and catalase， as well as chlorophyll and proline levels， were significantly higher in the LpDREB9 transgenic tobacco than in WT （P<0.05）. The malondialdehyde content was markedly lower in transgenic tobacco plants than in WT （P<0.05）， indicative of a lower level of membrane lipid peroxidation. These findings underscore the heightened capacity to scavenge reactive oxygen species in transgenic tobacco expressing LpDREB9， leading to enhanced drought tolerance. Hence， the LpDREB9 gene plays a pivotal role in augmenting the drought tolerance of transgenic tobacco. These findings provide the basis for further research on stress resistance at the molecular level in L. pumilum.

GLK （Golden2-like or G2-like） transcription factors belong to the GARP superfamily， whose members play crucial roles in plant growth and development. Members of the GLK gene family play important roles in regulating plant chloroplast development， chlorophyll biosynthesis， and the abiotic stress response. The GLK gene family has been systematically identified in many plant species， but not yet in tetraploid alfalfa （Medicago sativa）. In this study， we used bioinformatics methods to identify 100 GLK genes （MsGLKs） in the genome of the alfalfa cultivar “Xinjiang Daye”. Further analyses were conducted to explore the physicochemical properties of their putative encoded products， chromosome localization， phylogenetic relationships， cis-acting elements in their promoter regions， and transcript profiles under osmotic stress and exogenous abscisic acid （ABA） treatment. The results showed that the 100 MsGLK genes were unevenly distributed on the 32 chromosomes， and encoded polypeptides with sequence lengths ranging from 201 to 860 amino acids. In a phylogenetic analysis， the MsGLK family members were divided into 13 groups. A collinearity analysis detected 193 MsGLK gene duplicates in the alfalfa genome， and a analysis of the ratio of the number of nonsynonymous substitutions per nonsynonymous site to the number of synonymous substitutions per synonymous site （Ka/Ks） revealed that most of the duplicated gene pairs have undergone purification selection. A range of cis-acting elements were detected in MsGLK gene promoter regions， and were involved in plant growth and development， hormone responses， and stress responses. Analyses of gene transcript profiles revealed that 12 MsGLKs showed tissue-specific expression patterns， and 25 MsGLKs were expressed in all tissues. Further RT-qPCR analyses revealed that some MsGLK genes were activated to some degree in response to drought stress， salt stress， and exogenous ABA treatment. The results of this study provide reference information for further research on the function of MsGLK genes and for the genetic improvement of stress resistance in alfalfa.

The aims of this study were to screen cultivars of silage maize （Zea mays） to identify those suitable for cultivation in forest-margin mountainous areas of southeast Gansu， and to determine the most appropriate cultivation methods. A field experiment was conducted with five varieties of silage maize， and their yields and nutrient contents were determined. A grey correlation analysis was conducted to rank the five varieties from most to least suitable on the basis of their attributes. Overall， the variety Tie Yan 53 performed the best， and could serve as the main variety for cultivation in southeast Gansu. The impact of different nitrogen application rates （0， 70， 140， 210， and 280 kg N·ha^-1） and different planting densities （60000， 67500， 75000， 82500 and 90000 plants·ha^-1） on the yields and quality of Tie Yan 53 was determined. The results showed that the maximum yield of Tie Yan 53 （38.80 t·ha^-1） was obtained with 210 kg N·ha^-1. Increasing the N application rate to 280 kg N·ha^-1 did not increase the yield， but resulted in the best nutrient status. The yield of Tie Yan 53 increased with increasing planting density， with the maximum yield achieved at 90000 plants·ha^-1. The crude protein content was highest at a planting density of 75000 plants·ha^-1， and the crude protein yield was highest at a planting density of 90000 plants·ha^-1. Considering the balance between N application， yield， and economic benefits， 280.74 kg N·ha^-1 is recommended as the appropriate N application rate for Tie Yan 53 in this area. To achieve the best yield and quality， the recommended planting density is 90000 plants·ha^-1.

This experiment was designed to investigate the effects of Lactobacillus plantarum and Lactobacillus brucei on the conventional nutrient composition and protein fraction of rape （Brassia campestris） straw， and in vitro rumen fermentation parameters in yaks. Four treatment groups with five replicates in each group were set up， including a control group （CON； without any bacterial preparation）， an LP group （with 1.0 g·kg^-1L. plantarum）， an LB group （with 1.0 g·kg^-1L. brucei）， and an LPB group （with 1.0 g·kg^-1L. plantarum+1.0 g·kg^-1L. brucei）. Rape straw was used as fermentation substrate. The rape straw was cut to 2 cm lengths and mixed well with the bacterial preparation， then packed into polyethylene bags. The bags were evacuated and anaerobically fermented at room temperature for 45 days. Samples were taken to determine the nutrient composition， Cornell net carbohydrate and protein （CNCPS） system data， and yak in vitro rumen fermentation parameters of the straws. The results showed that： 1） Compared with the CON group， the pH values of the LP， LB， and LPB groups were decreased （P<0.05）， and lactic acid content was increased （P<0.05）， with the highest values recorded in the LPB group. 2） Compared with the CON group， the neutral detergent fiber （NDF）， acid detergent fiber （ADF）， and cellulose content of the LP， LB， and LPB groups were decreased， and the ether extract content was increased （P<0.05）. Furthermore， the NDF， ADF， and acid detergent lignin levels （ADL） in the LPB group were lower than those in the other two treatment groups （P<0.05）. 3） Compared with the CON group， the rapidly degraded protein （PB1） and moderately degraded protein （PB2） in each treatment group did not change significantly （P>0.05）. The content of non-protein nitrogen （PA1） in the LPB group increased （P<0.05）， and the content of unavailable protein （PC） decreased （P<0.05）. The content of unavailable fiber （CC） in each treatment group decreased （P<0.05）， and the content of available fiber （CB2） and non-structural carbohydrates （NSC） increased （P<0.05）， compared to CON. The content of CC in the LPB group was lower than that in CON， LP and LB groups （P<0.05）. 4） After 72 hours in vitro gas production of rape straw， there was no significant difference in rumen fluid pH among the groups （P>0.05）. The NH₃-N content in each group was lower than that in the CON group （P<0.05）. The dry matter degradation rate （DMD） and volatile fatty acid （VFA） content in the LPB group were higher than those in the CON group （P<0.05）. In conclusion， the anaerobic fermentation of rape straws inoculated with bacterial preparations improved the nutritional value of the rape straws， and different bacterial preparations differed in their efficacy. On a multivariate comparative score， the treatments ranked： L. plantarum+L. brucei>L. plantarum>L. brucei.

This experiment studied the effects of different feeding methods in the cold season on the growth and physiological adaptation of Qinghai Plateau-type yaks. Three hundred and twenty male yaks of 18 months of age with no significant difference in natural body weight ［（142.45±2.65） kg］ were selected and divided into two groups. One group was naturally grazed in the original conditions， and the other group was fattened for six months in full housing at low altitude. At the end of the experiment， three yaks from each group were randomly chosen and slaughtered to determine of growth performance， slaughter performance， and blood physiology and biochemistry. After 6 months in the different feeding regimes during the cold season， the weight， body length and chest circumference of yaks in the fattening group were higher than those in the grazing group， with high statistical significance （P<0.01）. Similarly， the pre-slaughter live weight， meat weight， bone weight， hoof weight， skin weight， meat∶bone ratio， slaughter rate， net meat yield， heart weight， lung weight and skin∶body weight of yaks in the fattening group were all higher than those of the grazing group， with high statistical significance （P<0.01）. Meanwhile， the head weight， carcass meat yield， liver weight， spleen weight and kidney weight of yaks in the fattening group were higher than those of the grazing group， but at a lower level of statistical significance （P<0.05）. The number of red blood cells and haemoglobin concentration of yaks in the fattening group were significantly higher than those in the grazing group （P<0.05）； the mean haemoglobin content of yaks in the grazing group was significantly higher than that of the fattening group （P<0.05）. Total cholesterol levels were significantly higher in the fattening group than in the grazing group （P<0.05）； calcium and phosphorus content was significantly higher in the fattening group than in the grazing group （P<0.05）. The economic benefits of the fattening group were higher than those of the grazing group， with high significance （P<0.01）. In conclusion， cold-season low altitude ex-situ fattening enhanced growth performance， nutritional metabolism， and optimized serum biochemical indices of yaks， which increased the economic efficiency of yak farming.

Understanding of the behavioral traits of mixed-grazed livestock in desert steppe is important when planning the sustainable use of grassland resources. This study was carried out in a desert pasture with mixed-grazing by cattle and sheep in Boarder Yellow Banner， Xilingol League， Inner Mongolia Autonomous Region， China. Four cattle and eight sheep from the herds were selected to wear GPS collars containing three-axis acceleration sensors， and their temporal dynamics of grazing time （GTIME） and grazing overall dynamic body acceleration （GODBA） were analyzed. From the data， we explored the response patterns of grazing behavior traits of mixed-grazed cattle and sheep to the monthly changes in the grassland vegetation. GTIME and GODBA showed significant positive correlations in cattle and sheep grazed together on desert steppe pasture （R²>0.60）. Further， the results showed opposite patterns in the GODBA responses of cattle and sheep. Cattle were positively stimulated by above-ground biomass （P<0.05）， while negatively stimulated by Shannon index （P<0.01）. Sheep were negatively stimulated by above-ground biomass and the proportion of poisonous herbage （P<0.001）， while positively stimulated by Shannon index and forage crude protein content （P<0.001）. In addition， the 24-hour behavioral patterns of cattle and sheep on mixed pasture both exhibited “multimodal” characteristics， and tended to shrink with the month changes. Furthermore， there were significant differences between cattle and sheep in acceleration intensity during different types of activity， with the acceleration intensity of sheep being significantly higher than that of cattle （P<0.05）.