Melatonin is a small molecule indolamine hormone that widely exists in plants,and the studies have already clarified its synthetic pathway,catabolism and physiological functions. Melatonin can act as a signaling molecule to regulate plant circadian rhythms,seed germination,root and flower development,and also help to enhance the resistance of plants to various stresses. In this paper,the physiological functions of melatonin in regulating growth and development of herbaceous plants were summarized up,and its regulatory effects in response to abiotic and biotic stresses were particularly focused on. Additionally,functional study on melatonin in growth,development and stress resistance,as well as its application in stress resistance breeding in forage species were prospected. This review is expected to provide insight into improving the stress resistance,yield and quality enhancement of forage plants by using melatonin.

In order to investigate whether artificial grassland can be established in Nagqu area and what kind of forage species is suitable for planting,this experiment selected the cold and drought-resistant forage species to carry out an introduction and screening test artificial grassland in the area. Through the comparison and evaluation of the harvested forage yield with the yield of natural grassland in Nagqu and other artificial grassland in the four major grassland areas in China,it can be seen that the yield of the harvested forage in the experiment is exponentially higher than that of the natural grassland in Nagqu,and the average yield of the artificial grassland in the experimental area is not lower than that of the artificial grasslands in the other grassland areas in China,which indicate that high yielding artificial grassland can be established in Nagqu region under adequate water and fertiliser management conditions. At the same time,the screening of suitable pasture species was carried out based on the seedling emergence and growth of different pasture species in the year of sowing and the seedling emergence of perennial pasture species in the following year (i.e. overwintering ability). The results showed that Avena sativa, Triticum secale, Brassica rapa and Brassica napus were suitable for planting in the Nagqu area. Elymus sibiricus and Elymus nutans,which were able to overwinter successfully,can be used as screening species for perennial grassland,but their stability in the second and subsequent years after overwintering remains to be studied.

Grazing is one of the most important uses of grassland ecosystems,and different grassland types,grazing intensities,herbivore assemblages,grassland use types and climate change all influence the structure and function of grassland ecosystems. It is very important to understand the mechanisms of grazing and climate change on grassland ecosystems for their sustainable development. In order to provide a theoretical reference for the adaptive management and sustainable development of grassland ecosystems,this paper provided a systematic review of the mechanisms by which grazing affects the structure and function of grassland ecosystems,and provided an outlook on several important research directions in this theme,and future research issues as the following:(1) to improve spatial coupling analysis in grazing grassland ecosystems;(2) to focus on multifunctionality studies of grassland ecosystems;(3) to elaborate the multi-factorial nested experiments on grasslands in the context of global change;(4) to refine the mixed grazing experiments with different herbivore assemblages;(5) to standardize the methods of grassland ecological experiments.

Inner Mongolia grassland is an important livestock production base and northern ecological security barrier in China,and its economic development and ecological protection issues are the hot topics of research nowadays. Family ranch as a major typical form of livestock production organization has become an important element in the development of agriculture and animal husbandry in Inner Mongolia. In recent years,climate change and human disturbance have caused the degradation of grasslands. This not only brings about problems such as the decline of ecosystem function,but also has an important impact on the economic development of family ranches. This paper discussed the development and definition of family ranch,provided an overview of the roles produced and the impacts caused from the management strategies of family ranch under different grassland types in Inner Mongolia,and finally raised questions and outlooks on the business model,herders' business awareness,management system,financial system and social service system,and landscape remote sensing technology applications relevant to the family ranch in Inner Mongolia. It is expected to provide a scientific reference for achieving grass-livestock balance at the scale of farmer's household in Inner Mongolia,while improving the economic efficiency of farmers and herders.

As one of the important industries in the field of agriculture,the grass seed industry is playing an increasingly important role in improving the efficiency of farming,increasing the income of farmers and herdsmen,and promoting high-quality economic and social development. The collection,preservation,identification,evaluation and innovative utilization of germplasm resources and the breeding of new varieties (lines) have become hot topics in the current research of grass seed industry. This paper mainly summarized and prospected the genetic diversity of grass germplasm resources from four aspects:morphology,biochemistry,cytology and molecular level,aiming to provide reference for the creation and breeding utilization of grass germplasm resources.

Leaf chlorophyll is a critical substance for plant photosynthesis,while nitrogen is an important component of chlorophyll. Therefore,soil nitrogen may be an important factor to affect leaf chlorophyll content. However,little attention has been paid to whether leaf chlorophyll content exhibits a nonlinear response to a soil nitrogen gradient and the possible mechanisms behind it. In this study,dominant plants in alpine meadows on the Qinghai-Tibet Plateau were used as the research object,and an eight-year nitrogen addition gradient experiment was conducted with nitrogen addition levels of 0,2,4,8,16,and 32 g·m ^-2·a ^-1. We found that leaf chlorophyll content showed a first increasing and then decreasing pattern in response to nitrogen addition gradient,and the peak value mostly appeared at 8 g·m ^-2·a ^-1. At low nitrogen levels,leaf chlorophyll content was positively correlated with soil inorganic nitrogen but negatively with soil pH and plant height. At high nitrogen levels,leaf chlorophyll was not correlated with soil inorganic nitrogen or pH,but exhibited a nonlinear relationship with plant height. In addition,we found that regardless of low or high nitrogen additions,there was a parabolic relationship between leaf chlorophyll content and specific leaf area. This study demonstrated that the leaf chlorophyll of alpine plants exhibited a threshold in response to nitrogen additions gradient,and the underlying mechanisms below or above that threshold are different. Overall,this study suggests that in the context of nitrogen enrichment,the relationship between alpine plant chlorophyll and soil nitrogen availability is complex,which may further affect carbon sequestration in alpine grassland ecosystems.

Grasslands are important natural resource and ecological barrier in our country. Grassland ecological restoration is an important part of China's ecological conservation, as well as an important approach to enhance the ecosystem service function and carbon sequestration potential of grassland. Extensive studies have been conducted on degraded grassland, and many effective restoration practices have been proposed. However, there is a lack of comprehensive and target-oriented summaries of these restoration practices. This study conducted a systematic review of domestic and international research on grassland ecological restoration based on bibliometric research approach. We summarized the three stages of grassland ecological restoration in China and explored a regional-classified-hierarchical ecological restoration model for grasslands under different regions, different degradation types and different degradation degrees. Additionally, we provided relevant suggestions for the future development of grassland ecological restoration in China, and aimed to provide scientific basis for the ecological restoration and sustainable management of grasslands in our country.

In order to screen out the pre-emergence herbicides suitable for soybean-maize strip intercropping field,10 herbicides were tested in the study,and the effect on weed control and the safety of Glycine max and Zea mays were determined. The results showed that S-metolachlor,metolachlor,acetochlor,flumetsulam,prometryn,thifensulfuron-methyl and 2,4-D isooctyl ester were safe for soybean and maize at the recommended dosage,but pendimethalin caused a slight phytotoxicity to soybean. Both metribuzin and butachlor caused a slight phytotoxicity to both soybean and corn,which recovered after 25 days since those herbicides application. The control efficacies of S-metolachlor,metolachlor,pendimethalin and acetochlor on Setaria viridis and Digitaria sanguinalis were over 90%. The control efficacies of flumetsulam and prometryn on Amaranthus retroflexus and Chenopodium album reached above 90%,while the others had a lower control efficacies. The results above indicated that in soybean-maize strip intercropping field,S-metolachlor,metolachlor,and acetochlor should be applied when there were a large number of gramineous weeds;and flumetsulam or prometryn is the first choice to control broadleaf weeds.

To investigate the effects of different grazing patterns on plant community characteristics in winter pastures of alpine meadows in Qilian Mountains,three different grazing patterns (Grazing,M1;Grazing+Supplemental feeding,M2;Enclosure,M3) were set up in Yeniugou Township,Qilian County,Qinghai Province,and the results of one-way ANOVA and network analysis were conducted to characterize the plant community indicators,biomass differed significantly ( P<0.05);species richness increased significantly in the M2 mode,by 22% compared with M1 and by 10% compared with M3;the Shannon-Wiener index and Pielou evenness index of plant communities did not differ significantly in different grazing modes;the results of network analysis showed that the key species in the M1,M2 and M3 modes were,in order: Sibbaldianthe bifurca, Koeleria macrantha,and Potentilla multicaulis;the plant community functional group characteristics indicated that different grazing patterns had significant effects on plant functional group biomass allocation. Therefore,the appropriate increase of supplementary feeding in winter pasture grazing in Qilian Mountains can effectively maintain the stability of winter pasture grass communities and have a positive impact on the healthy development of alpine meadow ecosystem.

Grass seeds are the foundation of lawn industry,but we lack our own turfgrass varieties and the turfgrass seeds used in practice mainly rely on importation from abroad. Therefore,turfgrass breeding needs to be strengthened urgently. The conventional breeding cost a long period of time,low efficiency and is difficult to achieve precise targeted breeding. However,modern biotechnologies provide a new and effective way for turfgrass breeding,in which the key is a construction of an efficient regeneration system for turfgrass to accelerate the propagation speed,and be carried out its genetic transformation with regeneration system. This review mainly summarized the researches on the regeneration systems of some cold season and warm season turfgrasses in recent years,and focused on the key factors and existing problems affecting the regeneration process,and prospected the future development of turfgrass regeneration,with a view to provide a reference for the research,development,promotion,and application of new turfgrass varieties in the coming days.

In order to accurately evaluate the stability and adaptability of major domestic and foreign forage oat varieties in different areas of Sichuan and the representativeness and differentiation ability of the different testing sites,the bipolt and BLUP prediction model were used to jointly analyze the yield data of 12 oat cultivars tested in five testing eco-geographical sites in 2018. The results showed that cultivar 'Sun God' and 'Charm' had a fecundity and stable yield with a high potential to be planted in a large scale in Sichuan Province. The cultivar 'shooter' achieved a high yield in Hong Yuan,Aba,and can be extensively planted in high altitude areas with similar ecological conditions. Hongya county of Meishan city has good representativeness and distinguishing power,and is an ideal place for testing trial and promotion showing of oat varieties. In this study,we objectively evaluated the adaptability of oat varieties and the representativeness and differentiation capability of the candidate sites,our results can provide a basis for the selection of the excellent oat varieties and/or testing sites for the production of high-quality oat forage in Sichuan Province.

Taking 1 329 core journal articles on the researches on saline-alkali soil improvement with plants from 2000 to 2022 retrieved in CNKI and Web of Science (WOS) databases as the data source,the data visualization software was used to qualitatively and quantitatively analyze the clustering,hot spots,co-occurrence,semantic network and other presence,and the current situation of plant improvement saline-alkali land at home and abroad was clarified from the perspectives of research trends,research hotspots and improvement effects of plant improvement saline-alkali land. The results show that the number of literature on saline-alkali land research is increasing year by year,and the effect of plants on improving saline-alkali land is a hot research problem. Herbaceous plants are the most commonly used plants in saline-alkali land improvement,and there are mainly 15 species of shrubs and trees. Planting plants can mainly reduce soil pH,salt content and salt ion concentration in saline-alkali land,improve soil physical characteristics,and increase soil fertility level. The improvement effect of different plants on saline-alkali land is different,and the establishment of saline-alkali plant bank as the basis for improving saline-alkali land is the focus of future research in this field,and the progress of saline-alkali land improvement is reviewed based on existing research,which has guiding significance for the subsequent ecological restoration and sustainable development of saline-alkali land.

Arbuscular mycorrhizal fungi (AMF) and rhizobium are two important groups of soil microorganisms that form a symbiotic system with plants,helping the plant take up nutrients and water,and promoting plant growth. Depending on the host plants and nutrient conditions,the mediation on plant growth by AMF and rhizobium is different. In this study,the effects of inoculation with AMF and rhizobium (single inoculation and double inoculation) on plant growth were quantified by Meta-analysis,and the effects of host differences and nutrient addition on the symbiotic relationship were further analyzed. The results showed that co-inoculation with AMF and rhizobium broke the potential resource limitation and showed a significant synergistic effect compared to a single inoculation;host differences would affect the synergistic effect,which was manifested as a positive effect value of the total biomass of legumes greater than that of non-legumes,but the positive effect value of nitrogen and phosphorus content was smaller than that of non-legumes;by changing the “investment-reward”,nutrient addition would break the synergistic effect,and reduce legumes biomass and root colonization. Therefore,taking account of host differences and soil nutrient content is an important prerequisite for the use of mycorrhizal agents.

Informatization is a key measure to promote the high-quality development of grassland undertakings in the new era and realize the modernization of the governance system and governance capacity in pastoral areas. Grassland conservation and the modernization of pastoral areas in China urgently require information technology support. In this study,the needs of the informationization construction in the pastoral areas in China,the applications of cutting-edge information technologies in the fields of grassland conservation and animal husbandry production and herdsman’s living improvements in Chinese pastoral areas,and the current status of grassland informationization construction in China were analyzed and summarized. The challenges which the grassland informationization construction in China are facing was identified. Meanwhile,taking the needs for the informationization on grassland conservation and the practices and managements of the productions in pastoral arear as a root in this research,the mode of informationaization in pastoral area in China was studied by taking into an account of the current infrastructure and scientific and technological development level in the pastoral areas,and by a following of the basic technical framework of informationization construction for the government. Starting from the construction of management display platform for government,the construction of applications integration,big data construction,the construction of infrastructure,and the construction of standard specification system and security and comprehensive social governance,a constructive system and framework for the informationization construction in grassland areas was proposed to provide a theoretical guidance and policy suggestions for informationization construction in pastoral areas,for a purpose of promoting the formulation of top-level designs for pastoral informationization construction and enhancing the efficiency of grassland informationization construction.

The party and the state pay a great attention to the Ecological Civilization Construction. It is an important part of the Ecological Civilization Construction in the new era to accelerate the construction of natural protected areas system with national parks as its major composed part. Promoting the construction of grassland natural parks is an important supplement to the construction of natural protected areas system in the new era. This paper reviewed,sorted out and summarized the construction processes of China's natural protected areas system and the developmental processes of grassland natural parks in the new era. The future development of grassland natural parks were carefully considered,and the macro development strategies and detailed suggestions on ecological protection,planning,feature mining and achievement sharing were proposed to provide reference for understanding and supporting the construction of grassland natural parks and the high-quality development of grassland cause in China.

In order to reveal the mechanism of arbuscular mycorrhizal fungi and plant symbiosis in restoring sandy degraded land in the northern farming-pastoral ecotone,this study selected three common grass species: Medicago satuva L., Bromus inermis Leyss and Festuca arundinacea Schreb as test materials in the degraded land, and the inoculation with Glomus etunicatum (GE),Glomus mosseae (GM),Glomus intradicular Glomus (GI) to those species and non-inoculated (CK) treatments were set up. The infection rate of endoroot balloon (GI) to Medicago satuva, Bromus inermis and Festuca arundinacea was the highest,followed by balloon Moses (GM),and the infection rate of balloon (GE) was the lowest. The biomass of alfalfa and fescue inoculated with GM and GI was significantly higher than that of inoculated with GE. Correlation analysis also showed that AMF infection rate was positively correlated with plant height,biomass and the number of tillers (or branches). In conclusion,the plant height,biomass and the number of tillers (or branches) of the three grassland plants were promoted by AMF inoculation. The combination of GI inoculation to Bromus inermis is suitable for the degraded land in the farming-pastoral ecotone,which provides a method of efficient vegetation restoration of the degraded land by microorganisms.

Forage is an important material basis for the benign development of herbivorous animal husbandry,and forage industry is an important part of its development,which plays an important role in optimizing agricultural structure. At present,Hulunbuir forage industry resources (27.96 million tons annual output) include mainly three plates:natural forage,artificial forage and straw forage,accounting for 32.8% of the effective utilization of resources. However,focusing on the industrial level,there are still many problems:no quantitative standard for classification and grading,loss and waste of grass resources,information asymmetry between market supply and demand,scientific and technological low level of forage industry,difficult formation of industrial chain,etc. At the same time,it is also facing with problems in resources,technology,policy and so on. This paper combed the present situation of the production of natural forage,artificial forage and straw forage industry in Hulunbuir,and comprehensively analyzed the problems existing in the development of Hulunbuir forage industry. Measures and suggestions were proposed,including optimized forage industry,strengthened forage storage construction to reduce waste and loss,diversified grass product technology research and development,artificial grassland construction to reduce grassland bearing pressure,supporting forage industry leading enterprises,and others,to provide reference for the high-quality development of Hulunbuir forage industry.

To explore the effect of poisonous weeds invasion on soil microorganisms in subalpine meadow in northwest Yunnan,the fixed monitoring site of shangri-La was selected as the research object,and three patches,which are dominated by Poa pratensis(set as control), Euphorbia jolkinii and Ligularia dictyoneura, were chosen as the sampling units,and the effect of poisonous weeds invasion and diffusion on soil microbial diversity of subalpine meadow was investigated in this study. The results showed as follows:compared with what in Poa pratensis patch,the density of soil bacteria,fungi and actinomycetes,the total OTUs and endemic OTUs,the α diversity and β diversity of soil bacteria and fungi were significantly increased in E. jolkinii patch and L. dictyoneura patch ( P<0.05). At the level of bacterial phyla,the relative abundance of Acidobacteriota and Chloroflexi decreased,while that of Proteobacteria increased. At the fungal phylum level,the relative abundance of Basidiomycota decreased,while that of Ascomycota increased . At the genus level,the relative abundance of Archaeorhizomyces decreased,while that of Hygrocybe increased contrarily. In conclusion,the invasion and diffusion of E. jolkinii and L. dictyoneura increased the density of soil microbial flora and the number of OTUs,changed the composition and diversity of microbial species,and promoted the growth and reproduction of soil microorganisms.

Lodging is one of the important factors affecting the yield and quality of oat. It is a prominent problem to be solved urgently in the breeding and production of oat. Strengthening the systematic research on the physiological and molecular mechanisms of oat lodging resistance is of great significance for promoting the germplasm innovation of oat lodging resistance and cultivation with high yield and high efficiency. Based on that objective,the study on lodging of oats is summarized systematically up in this paper,the influencing factors of lodging occurrence and the status quo of lodging resistance evaluation of oat were combed,the research progress in the morphology,physiology and anatomy of lodging resistance of oat was reviewed,the relationship of plant morphology,physical and chemical substances and cultivation measures with the lodging of oat was summarized up as well. In this paper,we prospected the researches on the characteristics of stem mechanics,endogenous material synthesis,genome wide association study (GWAS) of lodging resistance traits and quantitative trait locus (QTL) mapping.,functional gene mining and molecular mechanism analysis of oat,in order to provide references for the genetic improvement and breeding of the inverted resistance varieties of oat,and promote the development of researches on stress resistance of oat.

This study was conducted to evaluate the effects of different cover cropping strategies on the soil's physical and chemical properties,as well as the bacterial community structure in organic kiwifruit ( Actinidia chinensis) orchards in the Guanzhong Area. This experiment was conducted in 2021 at the Yangling Baiheng Organic Kiwi Orchard in Shaanxi Province. Three artificial cover cropping measures were tested: Lolium multiflorum+ Astragalus sinicus, Lolium multiflorum+ Glycine max, Lolium multiflorum+ Vicia villosa,with natural grass used as a control. The chemical properties and bacterial community structure of the soil in the topsoil(0~20 cm) were determined. The results showed that the organic matter of artificial grass increased by 8.8%~11.9% compared to the control,with the organic matter content of Lolium multiflorum+ Vicia villosa reaching 26.69 g·kg ^-1;The activities of soil urease,alkaline phosphatase,catalase were increased ( P<0.05),with Lolium multiflorum+ Vicia villosa having the most significant effect ( P<0.05). The bacterial beta diversity and the interaction relationship between bacterial communities in artificial cover cropping measures increased,while the abundance of metabolic functional genes in organismal systems significantly decreased( P<0.05). In summary,planting Lolium multiflorum+ Vicia villosa. and Lolium multiflorum+ Astragalus sinicus in organic kiwifruit orchards in the Guanzhong area can enhance the soil micro-ecological environment.

The loss of species due to climate change has profoundly affected ecosystem stability. Therefore,understanding how biodiversity loss affects ecosystem properties can provide valuable information for ecosystem stability management. In this study,the experiment of plant functional group removal for a short-term (2 a) was conducted to study the effects of the different removals on community biomass and soil properties in a Carex tibetikobresia meadow. The results showed that the aboveground biomass decreased significantly ( P＜0.05),but belowground biomass changed insignificantly in the different plant functional group removal treatments. Soil properties also changed under the different plant functional group removal treatments,among which,soil pH value increase insignificantly,soil water content also changed insignificantly,and some soil available nutrients decreased significantly( P<0.05). In conclusion,the loss of dominant functional groups of Sedge plants had a significant negative effect on aboveground biomass in the short-term (2a),and the functional group had a compensatory effect on community biomass after the loss of other functional groups. There might be a lag effect of soil water content in response to plant functional groups loss,while some soil available nutrients are more sensitive to the loss in the short term.

In order to reveal the impacts of future climate change on grassland ecosystems and their responses,this study assessed the spatiotemporal dynamics of global grassland ecosystems and their net primary productivity (NPP) in 2020-2100 based on four future climate scenarios (including SSP126,SSP245,SSP370,and SSP585) using an improved comprehensive sequential classification system (CSCS) and a segmentation model. Results showed that the global mean annual temperature (MAT) and mean annual precipitation (MAP) would exhibit an overall upward trend in all four climate scenarios. In the SSP126 and SSP245 scenarios,the global grassland area was expected to decrease by 1.94 million km ² and 1.78 million km ² by 2090 s,respectively,mainly due to the reduction of tundra and alpine steppe. In contrast,the global grassland area was expected to increase by 0.68 and 1.37 million km ² by 2090 s in the SSP370 and SSP585 scenarios,respectively,which was mainly caused by the increase in the area of the tropical savanna. Global grassland NPP showed an increasing trend in SSP126,SSP245,SSP370,and SSP585 scenarios,expecting to increase by 0.25,1.96,5.78,and 7.52 Pg DW by 2090 s,respectively. Tropical savanna would contribute the most. In the context of global warming and humidification,tropical savanna and tundra and alpine steppe grasslands would be more vulnerable to future climate change.

To better utilize alfalfa varieties and improve the efficiency and process of new variety selection,55 alfalfa varieties were used as materials in this study to analyze and evaluate agronomic and yield traits of alfalfa by coefficient of variation,genetic diversity index,correlation analysis,cluster analysis and principal component analysis. The results showed that the coefficients of variation of agronomic and yield traits were 6.89%~23.42%;the genetic diversity indexes 0.714 3~0.884 5 among which the highest diversity index was total leaf dry weight,while the lowest diversity index the stem-to-leaf ratio and fresh-to-dry ratio of the alfalfa varieties in second harvest. The 55 alfalfa varieties were divided into 3 main groups by cluster analysis,in which each group had obvious traits and characteristics;the varieties in group I and II need to be further mined for their excellent traits and can be utilized as complementary materials for breeding,and the varieties in group III can be directly introduced to the practical production,and can also be used as the parental materials in selection and breeding of highyield and good-quality varieties for the genetic improvement. Correlation and principal component analysis showed that number of branches,fresh-to-dry ratio,stem dry weight,leaf dry weight and plant height were the most important traits affecting the yield. The results of this study would provide a reference for the development and utilization of alfalfa varieties and the variety breeding of alfalfa in the semi-arid area.

Glycerol-3-phosphate acyltransferase (GPAT) is the rate-limiting enzyme of glycerol biosynthesis,participates in the biosynthetic pathway of various lipids,and plays important roles in plant growth and stress resistance. To understand the role of GPAT genes in the response of alfalfa ( Medicago sativa) to abiotic stress,a total of 73 MsGPATs genes in alfalfa were identified using bioinformatics methods in this study. Studies showed that the MsGPATs gene were unevenly distributed on chromosomes,and most genes exhibited segmental duplication. Phylogenetic tree analysis was classified into three subgroups. Gene structure and protein conservative motif analysis showed that most of the MsGPATs gene family members contained 2~3 exons or 11~12 exons,and at least one conserved motif. Promoter cis-acting elements analysis showed that different MsGPATs genes contained different light,auxin and stress response elements. Gene expression profiling analysis showed that a total of 10,5 and 18 MsGPATs genes actively responded to high salt,high alkali and mixed saline-alkali stress,respectively,which could be used as candidate genes for further research on saline and alkali tolerance in alfalfa.

In recent years,due to the continuous development of urban industry and the excessive use of chemical fertilizers,the lack of mineral elements and pollution in soil have seriously affected the sustainable development of agriculture. As a natural biological bacterial fertilizer,arbuscular mycorrhizal fungi (AMF) is able to effectively promote the absorption of mineral elements and improve growth conditions around plants. At the same time,in heavy metal contaminated soils,AMF can reduce the toxicity of heavy metal to plants and enhance the adaptability of plants to environmental changes. Up to now,great progress has been made in the researches on the physiological and molecular mechanism of AMF regulating the absorption of mineral elements by plants. A large number of mycorrhizal-induced genes have been identified,but a systematic and comprehensive summary is still lacking. Based on this,this paper summarized the relevant studies on AMF regulating the absorption of mineral elements in plants at home and abroad,and reviewed literature on the physiological and molecular mechanisms of AMF affecting the uptake of macroelements and trace elements by plants,and the mechanism of AMF alleviating the heavy metal toxicity to plant. According to the challenges and deficiencies of existing researches,the outlook is put forward,which aims to provide a certain scientific basis for the in-depth understanding of the mechanism of AMF affecting the absorption of mineral elements by plants and the agricultural application of biological bacterial fertilizer.

In recent times,more attention has been paid to the production of corn silage for the development of herbivorous animal husbandry in corn suitable planting areas,owing to its high yield,high dry matter,high fiber,high starch,high metabolizable energy and the ability to make high-quality silage. Corn stalks and seeds are rich in fiber and starch,respectively. Whole-plant corn,which is high both in fiber and energy,will be a preferred cultivated forage crop for the gradual shift from grain-based feeding systems to forage-based feeding systems in China. At the same time,the fact that the different plant parts of corn can be ensilaged separately makes it unique. In this paper,we focused on silage characteristics and their application scenarios for different plant parts of maize based on the recent research developments in stalklage,earlage,high-moisture corn silage,rehydrated corn grain silage,and whole-plant corn silage. Current research progress on the factors affecting the digestibility of fiber and starch in corn silage and strategies to enhance their digestibility were also reviewed,and the future development of corn silage in China was discussed.

To reveal the difference of photosynthetic characteristics and yield traits of different Medicago sativa varieties in coastal saline-alkali soil in Hebei Province,14 varieties of alfalfa were used as the tested material,Redundancy analysis and grey correlation method were used as comprehensive evaluate methods to analyze chlorophyll content,fluorescence parameters,photosynthetic parameters,plant height and biomass of different alfalfa varieties. The results showed that there were significant differences in yield characters and photosynthetic physiological characters among different alfalfa varieties. The actual photosynthetic efficiency Y(II),photochemical quenching (qP) and apparent electron transfer rate (ETR) of 'WL440HQ' leaves were the highest,and the non photochemical quenching (NPQ),Quantum yield of regulatory energy dissipation in photosystem Y(NPQ) and Quantum yield of non-regulatory energy dissipation in photosystem Y(NO) were the lowest,so its photosynthesis was strong and the dry matter of the plant was accumulated more. Redundancy analysis showed that alfalfa hay yield was affected by plant height,chlorophyll a(Chla),maximum photosynthetic efficiency(Fv/Fm),potential maximum relative electron transfer rate (ETR _max),Y(II),l _k,photochemical quenching(qP),NPQ,Y(NPQ) and ETR. Y(NPQ) and NPQ have negative effects on yield,and other factors have positive effects. Under the conditions of this study,'WL440HQ','Gannong No.9','WL358HQ','Zhongmu No.1' and 'WL525HQ' were ranked at the top,and their photosynthetic performance and yield traits were better. Therefore,these five varieties were suitable for plant in coastal saline alkali areas of Hebei Province.

Drought is one of the important factors that limit the growth of alfalfa. MYB transcription factor widely involves in the regulation of plant growth and development and abiotic stress. In this study,cloning and bioinformatics analysis of alfalfa MsMYB58 gene were performed to analyze the function of MsMYB58 in response to drought stress. The results showed that the length of MsMYB58 open reading frame was 1 002 bp,encoding a protein containing 333 amino acids,and the molecular weight was 37.80 kDa,which was a representative member of the R2R3-MYB family,localizing in the nucleus,cell wall,and membrane. The tissue-specific expression of MsMYB58 was mainly in stems and the least in roots. The expression levels of MsMYB58 showed different trends in abscisic acid (ABA),salt (NaCl) and natural drought treatment. Under drought stress,overexpressing MsMYB58 in tobacco showed a significant increase in catalase,peroxidase and superoxide dismutase activities and proline content,a significant decrease in malondialdehyde content,a significant increase in chlorophyll fluorescence parameters Phi2 and F _v/F _m,and a significant decrease in NPQt. In this study,the function of alfalfa MsMYB58 in response to drought stress was investigated and provided a theoretical basis for further excavation of drought-responsive functional genes in alfalfa.

Eight alfalfa varieties( Medicago sativa L.)introduced at home and abroad were used as test materials to compare and study the leaf characteristics,yield traits,and photosynthetic physiological properties of different varieties. Correlation analysis and throughput analysis were used to explore their correlation with yield and provide a basis for the screening of high-yielding alfalfa germplasm. The results showed that the variation of single plant dry weight of alfalfa varieties for the test was 0.88~1.21 g. The correlation between various traits and single plant dry weight was ranked in order of magnitude as follows:single leaf dry weight > specific leaf weight > transpiration rate > number of leaves per plant > leaf shape index,with single plant leaf dry weight being the most prominent leaf characteristic indicator. The degree of influence on the dry weight of a single plant was as follows in descending order:specific leaf weight > stomatal conductance > soluble protein > plant height > sucrose > soluble sugar > total chlorophyll,of which specific leaf weight was the main determinant of the dry weight of a single plant. In summary,the most important indicators for screening high-yield alfalfa germplasm were single plant dry weight and specific leaf weight. Among the 8 alfalfa varieties,‘Gannong No.9’,‘WL319HQ’ and ‘SG501’ have relatively high single-plant dry weight,single-plant leaf dry weight,and specific leaf weight,which can be studied and utilized as high-yielding germplasm in breeding work.

To study the effect of copper and nickel stress on the rhizosphere of Medicago sativa 'Qingshui',this paper took the soil contaminated with copper and nickel (the contents of Cu ²⁺and Ni ²⁺ are 324.1,and 271.1 mg·kg ^-1,respectively) in Jinchang area of Gansu as the study object,the effects of different copper and nickel concentrations (0,100,200,400,800,1 600 mg·kg ^-1,respectively) on the physicochemical and biological properties and bacterial communities in the rhizosphere soil of alfalfa were investigated by the pot experiment with the material of alfalfa 'Qingshui' tolerant to the contamination of copper and nickel. The results showed that with the increase of copper and nickel concentration,the contents of soil moisture,Cu ²⁺,and Ni ²⁺ in the rhizosphere soil increased;the contents of available nitrogen,available phosphorus,available potassium,microbial biomass carbon,microbial biomass nitrogen,microbial biomass phosphorus,and organic matter in the rhizosphere soil increased first and then decreased;the pH value and soil enzyme activity in the rhizosphere soil decreased. The richness and diversity index of bacterial communities first increase and then decrease,reaching to the peak level under copper and nickel concentration of 800 mg·kg ^-1. Proteobacteria,Actinobacteria,Acidobacteria,Bacteroidota,and Gemmatimonadetes were the dominant bacterial groups in the different samples. Through redundancy analysis and Monte Carlo permutation tests,it was found out that soil moisture content,available potassium,and catalase were the dominant factors affecting the changes in bacterial community structure in the rhizosphere of Medicago sativa 'Qingshui' under copper and nickel stress.