Glutathione (GSH), an important antioxidant in plants, can scavenge the redundant active oxygen free radicals produced during cell metabolism processes and relieve the damage caused by membrane lipid peroxidation. GSH contributes to the role of adversity stress resistance in plants. This review summarizes GSH activities including the types of GSH in plants, the application of GSH and the physiological mechanism of GSH protecting plant cells including scavenging intracellular active oxygen free radicals, forming non-toxic compound by combining with toxic heavy metal material, absorbing and transporting amino acid, resisting to adversity stress (temperature stress, drought stress, heavy metal stress and salt stress). GSH metabolism plays a positive role for understanding the physiological function of plant antioxidants, knowing the mechanism of scavenging active oxygen free radicals, and studying plant resistance.

Seed dormancy and germination are complex adaptive traits of plants influenced by a great number of genes and environmental factors.Although the utilization of quantity genetics methods(such as QTL analysis) and mutant approaches have made great development for dormancy and germination,the detailed mechanisms of dormancy and germination are not yet fully reported.Hormone,a factor to initiate seed germination,plays a key role in the regulation of seed dormancy and germination.Therefore,the relation between hormones and both germination and dormancy continues to be a research focus of seed physiology and biochemistry.With advancing understanding of the molecular biology and the discovery of a large number of mutants,regulatory mechanisms for a single hormone and interactions among hormones during seed dormancy and germination processes are better known.However,little knowledge about key points of networks for different hormones is known.This paper will focus on the functions of abscisic acid(ABA),gibberellin(GA),ethylene(ETH),brassinosteroids(BR) and other hormones during seed dormancy and germination progress,and further discusses the signaling relationship among these four hormones.

Fusarium oxysporum is one serious soil-borne pathogenic fungus and is listed as one of the top ten plant fungal pathogens in the world. This fungus can infect more than 100 economically important crops such as cotton,soybean,watermelon,banana,tomato and alfalfa,causing wilt and root rot. The detection and quantification of F. oxysporum in soil and plant root tissues is the basis for early diagnosis and effective control of the disease. This article summarizes the research progress and application of F. oxysporum detection and quantification methods at domestic and overseas,mainly including medium colony plate dilution method,conventional PCR and real-time fluorescent quantitative PCR,etc. This review provides theoretical guidance for F. oxysporum detection and quantification in agriculture.

Different degree degradation of grassland ecosystem has been found under the stress of population increasing and impact of modern agricultural and industrial demands.The degradation of grassland ecosystem includes qualitative and quantitative changes in grassland composition,structure,process and function.They are the foundation and precondition of ecological restoration for the understanding of degraded grassland concept,driving forces,process and diagnosis of degradation degree.A series questions about grassland degradation was discussed systematically in this paper by summarizing former studies,and a conceptual model of grassland degradation was made."Natural grassland ecosystem" characterized by mild disturbance from human beings or nature was suggested to be "Model Grassland Ecosystem" for degradation research from an ecological point of view.Diagnostic approaches of grassland degradation were summarized as biological approach,habitat approach,function/service approach.The available diagnostic methods and their indices(system) related to grassland degradation degree were analyzed;and integral critical point during diagnosis of degradation degrees and the restoration precautions of degraded grassland were discussed.

Turf grass industry stepped into a stage of comprehensive development with rapid economic development and accelerating urbanization of China. It became a new growth point of national economy for the greatly enriched boundary. The concept and industrial structure of turf grass industry were defined and discussed in this paper. The industrial developments in the past ten years were respectively summarized from market, production, service and scientific education system. Main tasks of turf grass industry development in the future were summed up respectively to include industry standard, enhancing industry management, strengthening education and scientific research, and improving scientific and technological output.

Natural grassland is the survival and development basis of inhabitant in pastoral areas. In recent years, grassland degradation resulted from human factors and subsequent natural factors have posed a threat to the sustainable development of animal husbandry. Poisonous-weeds growth grassland is an important index of grassland degradation. The category and distribution of poisonous weeds, the situation of integrated control and the reasonable utilization of poisonous weeds were summarized in this paper. The 1300 species of poisonous plants (140 families) were found in China, in which 23 species caused serious damage to livestock industry. The locoweeds (species of Oxytropis and Astragalus), Stellera chamaejasme and drunken horse grass ( Achnatherum inebrians) of 23 species were mainly distributed in Qinghai, Tibet, Xinjiang and Inner Mongolia where were the main grassland regions of China, and their damage to livestock industry accounted for 80% of all livestock losses in the temperate grasslands of China. Therefore, the restoration of grassland ecosystem is a key of effective poisonous plant control. It is necessary to establish a technical system of integrated poisonous weed management, including an ecological management, chemical and mechanical removal.

Plant growth promoting rhizobacteria (PGPRs) exist in soil or are attached to plant roots with the functions of growth promotion and yield improvement. In addition,PGPRs can enhance plant resistance to biotic and abiotic stresses. Nowadays,with the development of green and sustainable agriculture,microbial fertilizer has become a new type of popular of fertilizer. Therefore,researches on isolation and characterization of PGPRs,their interaction with plants and the development of microbial fertilizer containing PGPRs are attracting more and more attentions. In this paper,the research advances on PGPRs,including their growth promotion mechanisms (nitrogen fixation,phosphorus solubilization,potassium releasing,iron solubilization,plant hormone secretion,release of volatile organic compounds etc..) and tolerance enhancement of biotic stresses (pathogens and pests) and abiotic stresses (drought,salinity and heavy metals),were reviewed. Finally,the research directions on PGPRs in the future were prospected.

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.

The ‘black soil land’ degraded grassland is the unique result of global grassland degradation's behavior in the Sanjiangyuan region of Tibetan plateau that had severely reduced the ecological function and pastoral industry in the Sanjiangyuan region. Based on the investigation of more than 290 publications and project repots in recent ten years, the authors reviewed the main studys and progresses in restoring engineering of ‘black soil land’ degraded grassland. This review discussed more about some new theory views, such as ‘black soil land’ second emergence, hydrothermal-hole effect of ‘black soil land’, temporary-steady state of ‘black soil land’ sown grassland etc. For the technique of restoration and rehabilitation, the author proposed some future technique, such as the technique system of ‘regional separation-vegetation classification-degradation degree-restoring phase regulation’,more species numbers mixed (>10) of seed materials for artificial plant community construction, human regulation of launching and inducing self-restoration for ‘black soil land’ sown grassland vegetation, and self-restoration ability and the near-nature restoration model, launching the second background of investigation for ‘black soil land’ in time, developing the low-cost model of restoration, then that can promote sustainable ecological building in the region Sanjiangyuan.

Cellulose is a biopolymer of considerable economic importance,it has a profound effect on human food, clothing and the development of new energy. In recent years, research focus on the cellulose is purified cellulose synthase proteins and synthesis cellulose in vitro, for that reason acquire new knowledge of structure and function about cellulose synthase(CESA)and cellulose synthase complex (CSC) is particularly important. Crystallography and 3D modeling technology application in protein structure prediction, overthrew the microfibril synthesis of the original model, and puts forward new speculation on the basis of the data. This paper summarizes the latest researches of CESA proteins biochemical structure, function, regulation of transcription and translation after modification, provides a new basis for follow-up study.

Ethephon (2-chloroethyl phosphonic acid, an ethylene-releasing compound) is a plant growth regulator with various systemic properties. It is widely used on wheat, coffee, tobacco, cotton, and rice in order to help fruit to mature more quickly. Various effects of ethephon treatment on plants have been published. This article focused on reviewing the effects of foliar ethephon application on plant drought tolerance. To date, either promotion or inhibition of drought tolerance by ethephon treatment was reported. The effect of ethephon treatment on plant drought response was dependent on many factors, such as the concentrations of ethephon solution, plant species and cultivars, plant developmental stages, and treatment methods. In addition, the possible mechanisms of ethephon treatment affecting plant drought tolerance were discussed.

Grassland accounts for about 40% of the total land area in China,but the long-term excessive resource utilization by farmers and herdsmen results into large-scale grassland degradation,as output and input of grassland ecosystem in terms of energy flow and material circulation are out of balance. Since the 18th National Congress of the Communist Party of China,great efforts of grassland protection and restoration have been continuously made,and therefore the deterioration of grassland ecology has been preliminarily prevented. The construction of perennial mixed sowing artificial grassland is an important measure for animal husbandry development and ecological restoration of degraded grassland,and has great strategic significance for the sustainable development of grassland ecosystem and the construction of ecological civilization. In this paper,we reviewed the progress of the relevant researches in the recent 20 years,and put forward a theory of Quasi-stable state for the mixed sowing artificial grassland. We define the contents and significance of Quasi-stable state,and construct a technological system to maintain the Quasi-stable state in perennial mixed-sowing artificial grassland. This work provides guidance for the healthy and sustainable development of animal husbandry and ecological restoration in China.

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.

To investigate the characteristics of plant root pull-out resistance of alpine grassland in the source region of the Yellow River,six dominant grass species were selected from the alpine grassland in the source region of the Yellow River in Henan County,Qinghai Province. Through in-situ pull-out test,single root tensile test and root-soil composite system direct shear test,the root pull-out resistance characteristics of six grasses were analyzed. The comprehensive effects of root diameter,root number,root length,soil density,moisture content,compactness,root content,single root tensile strength and cohesion of root-soil composite system on pull-out resistance were investigated. The results showed that:the root pull-out resistance of Kobresia humilis K. was the highest (46.50 N),followed by Kobresia pygmaea C. B. Clarke. (37.50 N), Poa crymophila Keng. was the smallest (16.45 N). There was a significant positive correlation between root diameter,root number,root length and root pull-out resistance,with correlation coefficients ( R) of 0.881,0.727,and 0.969,respectively. There was a positive correlation between soil density,soil compactness,root content,cohesion of root-soil composite system and root pull-out resistance,and a negative correlation between moisture content and root pull-out resistance. The results of this study provide theoretical guidance for exploring the mechanical mechanism of alpine grassland degradation in the source region of the Yellow River,and provide theoretical basis and practical guidance for effectively preventing and controlling of grassland degradation,soil erosion and other shallow surface disasters in the region.

Oat ( Avena sativa L.) is one of the main sources of roughage for ruminants,and it is beneficial to rumen health and production performance of cows because of it is rich in carbohydrates. Silage is one of the main forms of safe storage of oat,which has the advantages of good palatability and high digestibility. As for oat silage,predecessors have carried out a lot of researches,mainly focusing on the moisture,harvest period,additives,mixing and feeding of oat silage. Based on these,this paper summarized the researches on oat silage. The constraints affecting the fermentation and nutritional quality and the utilization value of oat silage were summarized,which would promote the concoction and utilization of high-quality oat silage.

Forage is of the indispensable importance to herbivores. The strategy of utmost spurring the development of the high-quality forage industry can be adopted by the measures of expansion of the forage sources,increment of the forage yields and extension of the animal products application in the line of the vital technical approaches such as,increasing grain production with the exploring of forage,saving grain supply with the exploring of forage,and replacing grain supply with the exploring of forage. In this way,we can achieve the conversion of forage into grain,and make an important contribution to enhance the level of national food security and comprehensively consolidating the foundation of food security.

Thesium chinense Turcz.,known as “plant antibiotic”,is an important Chinese herbal medicine plant for its purgative and detoxifying effects in China. Based on the characteristics of semi-parasitism,seed deep dormancy,short growth cycle,long dormancy period and low reproductive efficiency,this review summarized the research progress on the parasitic biology,growth of live plants,tissue culture and rapid propagation,cultivation of Thesium chinense Turcz. The main factors limiting the artificial cultivation of Thesium chinense Turcz. are climate,soil type,seed germination and the amount of nutrient accumulation in the roots of the plant,etc.,thus the corresponding cultivation methods are proposed. It would provide some valuable information for the future studies on the tissue culture reproduction,cultivation and utilization of Thesium chinense Turcz.

To optimize the process of extracting and separating flavonoids from alfalfa, different methods were adopted to extract and separate the flavonoids systematically. Results showed that 30% ethanol solution and water (pH=7.5) had the best effect on alfalfa flavonoids extraction. Leaching efficiency of the flavonoids were 0.46% and 0.49%, respectively. The highest content of alfalfa flavonoids extracted with water was 1.61% when pH was 9.0. The optimum pH was 2.2 for separation of alfalfa flavonoids and the content of flavonoids in the extractive was 9.80%. Different macroporous resins were used to separate alfalfa flavonoids extracted with ethanol solution. DS-17 showed the best separation effect and the content of flavonoids was 5.87%. The effect of macroporous resins on the separation of alfalfa flavonoids extracted by acid-isolation was analyzed. DM130 had the best effect and the highest contents of alfalfa flavonoids in two treatments were 24.25% and 29.35%, respectively.

The net ecosystem exchange of carbon dioxide (NEE) between terrestrial ecosystems and atmosphere is a major component of carbon cycle of terrestrial ecosystems called "breathing" of the terrestrial biosphere, and is great concerned in the research of global climate change. Grasslands, as a major component of the terrestrial ecosystems, comprising approximately 40% of the world's terrestrial surface, is sensitive to climate change. Grazing plays a significant role in the land use and management of grasslands. With the change in global climate, the impacts of different grazing intensities on grazing ecosystems have different ways. In this review, the effects of grazing on the characteristics of NEE in grassland ecosystems are focused in general based on factors in NEE composition and the pathways of grazing effects on NEE in grasslands. Grazing mainly disturbs the soil-vegetation interface of grasslands then affects grassland NEE through the disturbances on 1) plant, including effects on plant community composition, above and below-ground net primary production and litter; 2) soil, including the effects on soil respiration, soil nutrients especially soil carbon and nitrogen, soil temperature and moisture. The pathways of grazing effects on grasslands can also be applied in disturbances such as cultivation and defoliation and is of great importance in the investigating of NEE characters and carbon flux of different grassland ecosystems, particularly grasslands in different land-use, whether in carbon source or sink in certain degrees and their carbon storage capacity.

China has large area of grasslands, accounting for about 40% of the national total areas. Inner Mongolia grassland comprises more than 20% of China's total grasslands. In the recent past, Inner Mongolia grassland has been undergoing successive degradation driven by both natural factors and human disturbance, which exerts negative influence on carbon sequestration ability of the ecosystem. This paper reviewed the criteria, degree and current situation of grassland degradation in Inner Mongolia. Driving forces of grassland degradation in the region were probed in the aspects of human activities, climate change and material inflow and outflow in the grassland ecosystem. The basic progress of carbon cycle and the impact of grassland degradation on carbon sequestration were discussed. This paper also introduced the carbon sequestration potential of degraded grassland under varied restoration implementations. Finally, the strategy for preventing grassland from degradation and for enhancing the carbon sequestration ability was recommended.

Grassland is an important ecosystem and a natural ecological security barrier in the north of China with its important ecological and production values. In recent years, due to the unreasonable use of grasslands and abnormal changes in climate, grassland pests have been aggravated year by year, which seriously restricted the livestock production and ecological civilization construction in China. Based on historical data, this article summarized the characteristics of China grassland pests with many types, strong damages, and heavy losses, analyzed the staged effects of prevention and control, and objectively pointed out the current prevention and control work's lack of monitoring capabilities, funding, equipment, scientific research support, and lagging policies and regulations, and other major issues. It then systematically put forward working goals and specific measures for strengthening grassland pest control in terms of rationalizing management systems, strengthening system construction, improving monitoring and early warning levels, innovating control mechanisms and technologies, and increasing publicity and training efforts, which provide ideas for the next step in grassland biological disaster prevention and control.

In order to explore the potential distribution and influenceable factors of Littledalea in the Qinghai-Tibet Plateau,on the basis of our field investigation,we used Biomod2 ensemble models to predicate the distribution range and limited factors of three species of Littledalea ( L. racemosa, L. tibetica and L. przevalskyi). The results showed that the potential distribution range of L. racemosa was the biggest at 177 920 km ²,concentrated in southwestern Sichuan,northern Tibet. L. tibetica was the minimum at 90 190 km ²,concentrated in southern Qinghai and northern Tibet. L. przevalskyi concentrated in southwestern Gansu and northern Qinghai was about 157 830 km ². There were seven factors affected potential distribution of Littledalea,altitude was the principal factor. L. przevalskyi and L. racemosa should overspread than current distribution in the two kind of temperature increase simulation scenarios (RCP4.5 and RCP8.5) especially in the Northern Tibetan Plateau and Yushu Qinghai,but it should be shrinkage of total range of L. tibetica,its potential distribution appears in the most threaten of Littledalea in the future.

This paper reviews the different results and varying courses of taxonomic study on genus Medicago L.during the past century and places emphasis on the classification difference of taxonomic system between China and the western countries.By the Chinese system, Medicago, Trigonella L., Melissitus Medik.,and Turucania were separated as the difference genus,however all of them were classified to Medicago by the western system and the concept of M.sativa L.complex was established including ssp.sativa,ssp. falcata,and ssp. varia.In order to fully exert the advantage of Medicago germplasm resources in China and realize the genetic improvement function of excellent gene,it is suggested to recheck and study the current gene bank status of genetic resources and taxonomic system at molecular level.

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.

The high-quality forage is the basis of the healthy development of modern animal husbandry, which requires scientific control of planting, field management, harvesting, and processing. Drying is a key link in the post-harvest processing of forage, which significantly affects the quality of forage. To provide reference and technical support for the development of China's forage post-production processing industry, this paper summarizes the technology of forage harvesting and drying, and reviews and analyses the research advances of forage drying characteristics and drying equipment under the main drying methods in China and other countries. The main drying methods of forage grass include natural drying, hot air drying, high-temperature-fast-drying, solar drying, etc. In recent years, domestic scholars have studied the drying characteristics of forage grass under different drying methods. The domestic forage drying technology has been gradually improved, but it still lags behind the mechanized production technology of forage drying in foreign countries. There are problems of domestic forage drying technology, such as the mismatch between harvest and drying process, the lack of design standards for drying equipment, and small enterprise scale. Thus, the development direction of our country's forage mechanized drying processing industry is to formulate standardized forage drying processing technology, strengthen the research of forage drying technology, realize intelligent and integrated forage drying equipment.

To investigate the field drought resistance of Triticale wittmack ‘Gannong No.1’, two varieties of triticale (‘Shida No.1’ (CK1) and ‘Zhongsi 1048’ (CK2)) were used as control materials. The soil water content and physiological and biochemical indexes were measured after different days of drought stress, which would provide reference information for planting it in the rain fed farming area of northwest China. At the tillering stage of triticale, the soil water content, the contents of soluble sugar, proline (Pro), malondialdehyde (MDA), and the activities of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) in the leaves were measured at 7, 14, 21, 28, 35 and 42 days (the plants began to wilting) after drought stress by controlling water in rain-proof shelter. The result showed that except for MDA content, there were significant differences in soluble sugar, Pro, POD, SOD and CAT among varieties, drought stress days and interaction between them (P<0.01). These findings suggest that the drought resistance of three varieties decreased in the order:‘Gannong No.1’ > CK2 > CK1, so ‘Gannong No.1’ belongs to the middle resistant type, CK1 and CK2 belong to the drought sensitive type.

The carbon cycle of grassland ecosystem and its impact factors has become a study focus in the field of ecology, geology, botany and agronomy due to drastic global change in recent years. The present paper introduces the process of carbon cycle of grassland ecosystem and discusses the circulation of carbon among atmosphere sink, vegetation sink, herbivores sink and soil sink. Furthermore, the influences of climate factors, soil factors, CO₂ enrichment and human activities on carbon cycle were also analyzed here. The main problems and prospects of the study on grassland ecosystem carbon cycle are proposed.

The Denitrification-Decomposition (DNDC) model is a process-oriented computer simulation model of carbon and nitrogen biogeochemistry in agroecosystems by computing denitrification and decomposition process to simulate carbon and nitrogen transfer between soil and atmosphere, which is one of the most successful biogeochemistry models. In this paper, we reviewed the development of different versions of the DNDC model including those developed for different ecosystems. Also, we inducted carbon simulation papers in China agricultural research with DNDC, and summarized the advantages and hot spots in DNDC model utilization.

White clover ( Trifolium repens ‘Haifa’) was selected as experimental material in this study,and effects of seeds soaking with gamma-aminobutyric acid (GABA) on germination and tolerance to aluminium (Al ³⁺) stress were studied. The results showed that 1 mmol·L ^-1 Al ³⁺ solution significantly inhibited seeds germination,and the damage becomes more obvious with the increase of Al ³⁺ concentration. The germination and root length of seeds soaking with GABA significantly increased under Al ³⁺ stress with the most obvious effect under 4 mmol·L ^-1 Al ³⁺ stress. The antioxidant enzyme activity and non-enzymatic antioxidants content of seeds soaking with GABA significantly increased as well,thereby reducing oxidative damage effectively and improving cell membrane stability during germination under Al ³⁺ stress. In addition,seeds soaking with GABA also significantly increased genes expression of dehydrins under Al ³⁺ stress. Therefore,GABA-induced Al ³⁺ tolerance could be related to the enhancement of antioxidant defense to reduce oxidative damage caused by stress and the up-regulation of dehydrins genes expression during white clover seeds germination.

In order to explore the estimation method and driving factors of carbon storage in the Tibetan Plateau, carbon storage was estimated according to the measured data on basis of InVEST model, and then the driving forces were analyzed via structural equation model including meteorological and soil factors. The results showed that the overall carbon density in the Tibetan Plateau tended to be high in the southeast but low in the northwest. Furthermore, the carbon storage of alpine Kobresia and weedy meadow was the largest, reaching to 1.97×10 ¹¹ Mg. The aboveground carbon density was most sensitive to the change of total carbon density, with a slope of 44.73. Besides, precipitation, pH, cation exchange, organic matter, total nitrogen and available nitrogen were the important driving factors of carbon density in the Tibetan Plateau. The results can provide a scientific basis for the carbon pool management and human activities regulation of alpine ecosystem.