Nutrient characteristics of soils collected from five main plant species in Potentilla acaulis degraded grassland were analyzed and the allelopathy of P. acaulis ethanol extract on the seedling growth of four dominant species receptors ( Stipa krylovii, Artemisia frigida, Leymus chinensis and Agropyron cristatum) in P. acaulis degraded grassland were determined. The allelopathic ability of P. acaulis was discovered. The reason of P. acaulis becoming the dominant plant of degraded grassland was explained from the aspect of chemical ecosystem. Results were as follows: only available nitrogen content was lower in soils under P. acaulis than that beneath A. frigida, whereas others were higher. Allelopathic activities were related to extract concentration, test species and extract source. Ethanol extract of whole P. acaulis plant strongly inhibited the shoot and root growth of S. krylovii, and the inhibition was strengthened with extract concentration increasing. However, extracts showed a "low-promotion and high-inhibition effect" on the shoot growth of L. chinensis and A. frigida. The critical concentration value of extracts was 0.004 g·mL ^-1. Extracts of P. acaulis aboveground parts presented strong promotion on A. cristatum’s seedling growth at 0.002 g·mL ^-1 concentration. Allelopathy of P.acaulis underground parts were stronger compared with aboveground parts. Root growth had higher sensitivity than the shoot growth of all tested species seedlings. The greatest inhibition for seedling growth occurred in S. krylovii, followed by L. chinensis, A. frigida, and then A. cristatum.

To reveal the molecular mechanism of saline-alkaline tolerance from Leymus chinensis, the protein expression profile was constructed by 2D-DIGE and MALDI TOF/TOF. There were 74 protein spots presenting to express differentially after the total proteins were separated by 2D-DIGE. The 44 proteins of all presenting spots were up-regulated, and 30 proteins were down-regulated. Among the 74 protein spots, the annotations of the 33 differential expressed proteins were known. The expressed proteins were analyzed and compared by mass spectrum. Identified differential proteins took part in the energy exchange, metabolic processes of basal metabolism, photosynthesis, plant defense, and DNA synthesis, respectively. These works will be fundamental data to illuminate the molecular mechanism of plant defense to saline-alkaline stress.

The basic data involved the observed data of aboveground biomass from July to August in 2012 in Ili as well as the MODIS data during this period, and the purpose of this study was to protect and utilize grassland resources reasonably. The correlation relationships among enhanced vegetation index (EVI), normalized difference vegetation index (NDVI) and observed data of aboveground biomass were analyzed by linear regression model, quadratic polynomial regression model and index regression model. The spatial distribution of aboveground biomass in the grassland of Ili was simulated and analyzed. The results showed that a significant correlation relationship existed between vegetation index and aboveground biomass, while the quadratic polynomial regression model based on EVI(y = 14759x² - 4758x + 1346.2, R² = 0.8402) was the most suitable one, and estimation accuracy was 92.19%. The dry weight per unit area in the grassland of Ili was 1817 kg·hm^-2, and the total yield was 70.59×10⁸ kg in 2012. Along with the increasing elevation, aboveground biomass increased first and then decreased.

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.

Nitrogen is one of the key nutritional elements to determine the level of grass seed yields. The additional nitrogen supplying is beneficial for plant tillering, dry matter production, inflorescence formation and the dynamic changes of the yield components. In this paper, the conception, methods, research status and the application of critical nitrogen concentration dilution model have been reviewed, and the existing problems of its application in practical production were put forwarded. Finally, the application prospect of critical nitrogen concentration dilution model in the grass seed production were also prospected.

In order to amend acid soil by the rational application of green manures, a nylon bag method was used to research the dynamic change of total organic phosphorus and the contents of organic phosphorus fractions in acid soil during one year period after apply 4 tropical green manures (Indigofera zollingeriana, Indigofera spicata, Lablab purpureus, Alysicarpus vaginalis). The results indicated that the application of 4 green manures could increase the total content of soil organic phosphorus, the effect of Indigofera zollingeriana treatment was the best and that of Indigofera spicata treatment was the worst compared with others. The increase of soil labile organic phosphorus content was the most after the application of Alysicarpus vaginalis and was the least after the application of Indigofera spicata, whereas the increase of soil moderate labile organic phosphorus content was the most after the application of Indigofera zollingeriana and was the least after the application of Indigofera spicata. The decrease of soil moderately resistant organic phosphorus content after the application of Indigofera spicata was more than that after the application of Indigofera zollingeriana. The content of soil highly resistant organic phosphorus had the most increase after the application of Indigofera spicata, and decreased differently among different periods after the application of the other green manures; and the contents of soil organic fractions were also different among application periods. The apply effects of green manures were the largest after 30 d, and then differed from different green manures.

In order to learn the adaptability mechanism of white clover in the system of orchard and grass, the anatomical structures and photosynthetic characteristics of white clover leave were studied under no-shading, 50% shading and 70% shading, respectively. The results showed that the leaf area, upper epidermis thickness and spongy tissue thickness of white clover increased, whereas the other indexes of anatomical structure and P_n decreased as the increases of shading from apple tree. The upper epidermis thickness and the spongy tissue thickness were negatively correlated to P_n, whereas other indexes were positively correlated to P_n. In conclusion, the shading changed the anatomical structures of white clover leave and caused the decrease of photosynthetic rate.

Nitrogen (N) is the growth-limiting nutrient of plants in terrestrial ecosystems, especially in grassland ecosystems. The availability of N is determined by N cycling processes in terrestrial ecosystems. To better understand the N cycles, a key way is to exactly determine the rates of N transformation. To date, ¹⁵N stable isotope technique is highly recommended for quantifying the processes of N transformation. The isotope technique is generally classified into four categories as ¹⁵N natural abundance, ¹⁵N reduction, ¹⁵N pool dilution and ¹⁵N tracer techniques. In this paper, the progresses of researches on N transformation using ¹⁵N technique with a focus of ¹⁵N pool dilution and ¹⁵N tracer techniques in grassland ecosystems were summarized. Firstly, two detailed protocols were summarized from published papers for ¹⁵N pool dilution and ¹⁵N tracer techniques, respectively. Secondly, the recent findings of N transformation in response to human activities (fertilization, grazing, fire and mowing) and global change (global warming, increasing precipitation, atmospheric N deposition and increased CO₂ in atmosphere) using the above two N isotope techniques in natural grassland ecosystems were reviewed. The isotope techniques described here were also applicable to other terrestrial ecosystems, such as forest ecosystems and agro-ecosystems.

The responses of soil nutrients and plant community stability to different management modes,as well as the correlation between plant community stability and soil nutrients were studied in Stipa breviflora desert steppe in Ningxia. The results showed that the management modes significantly affected the variation of soil nutrients in 0～40 cm soil layer (P <0.05). Enclosure and replanting accelerated the accumulation of soil nutrient contents such as soil organic matter, total nitrogen, available phosphorus and available potassium,whereas medium grazing regimes decreased the contents of soil organic matter,hydrolysable nitrogen and available potassium. The different grassland management modes led to the different vertical distribution patterns of soil nutrition. The highest organic matter and total nitrogen contents were in 5～15 cm soil layer,but the highest available phosphorus and available potassium contents were in 0～5 cm soil layer. The plant communities of desert steppe under different management methods were all instability, but the plant community stabilities of 7-year and 10-year enclosed grasslands were higher than that of other modes. Furthermore, there was a significantly positive correlation between plant community stability and soil available potassium content (P <0.05), while there were no significant relationships between plant community stability and other soil nutrients.

Soil microorganism is an important part of grassland ecosystem and plays a significant role in the degradation of organic matter, nutrient cycling and plant diversity maintenance, etc. Taking advantage of the environmental sensitivity of soil microorganism, the degenerate system of grassland is able to be predicted early. The characteristics of soil microorganisms in natural grassland, and the advances of property changes of soil microorganism under different human disturbances including grazing, mowing, enclosure and nitrogen fertilizer addition treatments are reviewed in this paper. The prospects of research directions are forecast at the same time.

Experiments were conducted on the morphological characteristics of Sophora alopecuroide L. seeds, such as seed size, 1000-seed weight, and hard seed rate, the H ₂SO ₄ concentration and disposal time for hard seed breaking, and the effects of plant growth regulators and PEG on seed germination and seedling growth as well as the optimal soil moisture contents and sowing depth for seed germination. The results indicate that the average length of S.alopecuroide seeds was 3.865 mm, width 3.358 mm, thickness 2.321 mm,1000-seed weight 20.775 g, and hard seed rate 99%; the optimal disposal concentration of H ₂SO ₄ to break hard seed rate was 65% and time 20 min; 0.02% GA3 significantly improved the seed germination speed and seedling growth and PEG significantly increased seedling fresh weight; the optimal soil moisture contents and sowing depth for S.alopecuroides seed germination were 8%~12 % and 1~3 cm, respectively.

In order to further study the effect of artificial grassland on restoring the “heitutan”, the species compositions of plant communities in degraded artificial grassland, “heitutan” and natural grassland were analyzed. The results showed that the average species number of degraded artificial grassland, “heitutan” and natural grassland was 29,32 and 35, respectively. The important value of gramineae accounted for 21% of total community in the degraded artificial grassland, the important value of forbs accounted for 88.2% of total community in the “heitutan”.The important value of gramineae and cyperaceae accounted for 37.4% of total community in the natural grassland. Shannon-Wiener indexes, Simpson dominant concentration indexes and Pielou evenness indexes of different grasslands were all ordered as natural grassland >“heitutan”>degraded artificial grassland. Sorensen and Jaccard indexes showed that degraded artificial grassland and “heitutan” had the biggest community similarity, followed by “heitutan” and natural grassland, degraded artificial grassland and natural grassland had the smallest community similarity. The percentage of forbs in degraded artificial grassland was about 10% less than “heitutan”. The conclusion was that artificial grassland was degraded after several years, but the artificial grassland promoted the restoration of degraded plant community in “heitutan” to a certain extent.

The effects of experimental warming and nitrogen addition on soil respiration were investigated using Li-8100 soil carbon flux measuring system in the desert steppe of Inner Mongolia. The results showed that infrared radiator raised soil temperature obviously in 2010 and 2011, and the temperature of 0~30 cm soil layer was 0.4~1.0℃ higher than control. The experimental warming didn't change the soil moisture significantly. Both nitrogen addition and warming didn't change soil respiration significantly. The rate of soil respiration had significant seasonal variation, ranging from 0.15 to 3.66μmol CO₂·m^-2·s^-1. There was strong correlation between soil respiration and precipitation, and between soil respiration and the moisture of 10 cm soil layer, the correlation coefficients were 0.67 and 0.70, respectively.There was strong water stress occurred in the desert steppe of Inner Mongolia, so soil moisture was the predominant factor of affecting soil respiration. Nitrogen addition had no obvious effect on soil respiration.

Miscanthus Anderss is a new kind of lignocellulosic biomass for the production of biofuels. In order to improve the biomass production and resistance, the polyploid induction of Miscanthus have been widely researching all over the world.The purpose of this study is to investigate the effects of different treatments on the polyploid intrduction of Miscanthus Anderss. The DNA content of plant leaves is measured by flow cytometry instrument, the chromosome of roots is identified using chromosome technique, and the stomatal guard cells are compared between tetraploid and diploid. The results show that soaking callus in 10 μmol·L^-1 oryzalin solution with 1.02 mmol·L^-1 Ca²⁺ for 15 minute at 5℃ (35.19%) is the best method for polyploidy induction. The colchicine has higher toxicity than the others, and there is no significant difference between oryzalin and nocodazole.

The coverage, height, mouse-hole number, overground biomass of rangeland and the proportion of noxious-miscellaneous grass were measured. The results of ANOVA and LSD showed that the pasture managed by the medium scale of joint-household had higher coverage, height and overground biomass, lower mouse-hole number and the proportion of noxious-miscellaneous grass. In other words, the pastures managed by the medium scale of joint-household had the best quality. Then some economic knowledge was used in order to analyze the effects of humanistic factors on grassland quality. These results indicated that the herders of single household, small joint-household scale, and large joint-household scale would increase their herds because of loosely natural and managerial factors. The quality of pasture decreased due to the overgrazing. The herds of medium joint-household scale would not increase their herds because of the strictly natural and managerial factors. Therefore, the pasture managed by medium joint-household scale has higher quality than others.

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.

The effects of combined application of nitrogen and phosphorus fertilizer on the quality, grass yield and nutrient uptake of Leymus chinensis were analyzed at the west beach of Yanchi county in Ningxia. The results showed that the grass yield of Leymus chines ‘Zhongke No.2’ fertilized 120 kg·hm^-2 N with the base fertilizer of 120 kg·hm^-2P₂O₅ increased 1.5 times compared to control. The grass yield of Leymus chines ‘Zhongke No.2’ significantly increased after fertilizing more nitrogen (P<0.05). The uptake of nitrogen, phosphorus and potassium firstly increased and then decreased with the increases of nitrogen and phosphate. Rational fertilization could effectively increase the crude protein content of Leymus chinensis, and lower the content of nitrogen-free extractum. The quality of Leymus chinensis was the best after fertilizing 90 kg·hm^-2 N with the base fertilizer of 120 kg·hm^-2 P₂O₅ and the economic efficiency increased 1.48 times. Therefore, the combined application of 90 kg·hm^-2 N with the base fertilizer of 120 kg·hm^-2 P₂O₅ was recommended to be applied in the same region.

The effects of magnetized water treatment on the growth and nitrogen fixation of rhizobial strain on alfalfa under the constant magnetic field of 20000 Gs were investigated. The results showed that magnetization significantly affected the growth of XGL026 and reduced the OD value. The counts of viable bacteria in magnetized water culture media were the 86.96%~65.72% of ordinary culture media, and the counts of viable bacteria decreased with the times of magnetization increasing. The water magnetized more than three times significantly reduced the counts of viable bacteria (P<0.01). Pot alfalfa was inoculated by the marked bacteria strain XGL026-GFP. The irrigation of magnetized water had inhibitory effect on the colonization and survival of the rhizobial in alfalfa rhizosphere and reduced 46.4% nodule number compared to ordinary water (P<0.01). Both above- and below-ground of alfalfa were influenced by magnetized water treatment, the rates of N fixation decreased 21.06% and 20.48%, the amount of N fixation decreased by 26.64% and 37.5%, the dry biomasses were reduced by 27.62% and 13.46%, respectively. Thus the magnetized water treatment had effects on the growth, colonization and nitrogen fixation of rhizobial strain in alfalfa rhizosphere.

The allelopathic effects of Cleistogenes squarrosa on the seed germinations of Agropyron cristatum,Poa annua and Stipa grandis were investigated using indoor petri dish bioassays. The results showed that different mass concentrations(0.5, 5, 10, 20 and 50 g·L^-1) had different effects on the tested plants. And the effects were inhibitory when the concentration of extract increased. Compared with the control, the extracts of 50 g·L^-1 significantly inhibited the germination rates and germination indexes of P. annua (P<0.01), A. cristatum (P<0.05) and S. grandis (P<0.05). The aqueous extract promoted the germination rate of P. annua at lower concentrations and inhibited the germination rate at higher concentrations. When the concentration reached 50 g·L^-1, the response indexes of A. cristatum and P. annua were greater than S. grandis.

The effects of Monopotassium Phosphate, Fulvic Acid and Rare Earth Nitrate on the activity of alfalfa rhizobium were investigated using single factor and orthogonal experiment designs with Alfalfa rhizobium strain ACCC17631 and ACCC17676 as experimental materials in order to screen the optimum combination of medium. The results showed that Monopotassium Phosphate had significant influence on the activity of strain ACCC17631(P<0.01),the optimum concentration was 300 mg·L^-1, and no significant influence on the activity of strain ACCC17676. Fulvic Acid had highly significant influence on the activity of both test strains(P<0.01), the optimum concentration was 0.03% for strain ACCC17631 and 0.02% for strain ACCC17676. Rare Earth Nitrate could promote the growth of strain ACCC17631, the optimum concentration was 200 mg·L^-1, and had highly significant influence on the activity of strain ACCC17676(P<0.01), the optimum concentration was 400 mg·L^-1. The optimum combination of medium for ACCC17631 was 100 mg·L^-1of Monopotassium Phosphate, 0.03% of Fulvic Acid and 200 mg·L^-1 of Rare Earth Nitrates, for ACCC17676 was 300 mg·L^-1 of Monopotassium Phosphate, 0.02% of Fulvic Acid and 400 mg·L^-1 of Rare Earth Nitrates.

In order to understand the responses of antioxidant enzymes in cool-season turf grass under heat stress, the dynamic changes of five antioxidant enzyme activities and isozymes among different Kentucky bluegrass cultivars were investigated under 45℃/40℃(day/night) stress. The experimental cultivars were heat-tolerant ‘Thermal Blue’, heat-moderate ‘Utmost’ and heat-sensitive ‘Excursion’. The results showed that in three cultivars the activities of superoxide dismutase(SOD)were increased under 45℃/40℃(day/night) stress, whereas the activities of POD in the‘Utmost’ and ‘Excursion’ did not change significantly. The activities of peroxidase (POD) in the ‘Thermal Blue’ first increased then decreased. The activities of catalase (CAT) and glutathione reductase (GR) in the three cultivars decreased significantly with the period of high temperature stress prolonged. The activities of ascorbic acid peroxidase (APX) in the ‘Thermal Blue’ decreased significantly under heat stress for 1 d and 1.5 d, whereas the activities of APX in the ‘Utmost’ decreased under heat stress for 0.5 d then increased after 1 d, the activities of APX in the ‘Excursion’ increased significantly after 1.5 d. And the activities of APX in three tested cultivars had no significant difference after heat stress compared with before heat stress. Meanwhile, the isozymes of SOD, POD, CAT in the three cultivars remained unchanged. The expression levels of GR isozymes declined and the expression levels of APX isozymes increased in heat-tolerant cultivar ‘Thermal Blue’, whereas the expression levels of APX isozymes did not change in heat-sensitive cultivar ‘Excursion’.

A mimic 5-year temperature increased in a greenhouse raised the soil temperature of 10 and 20 cm depth 1.86℃ higher than that in the open, the 10 and 20 cm above ground air temperature 1.15℃ higher, and the soil surface temperature 1.87℃ higher than that in the open respectively, The extent of temperature increase was generally greater in the early plant growing season than in the later stage and the plant withering period.The result showed that in the first few years of the 5-year experiment, the yearly biomass from the greenhouse is weightier than that of the control in the open.However, after the 5-year period,the yearly biomass form the greenhouse decreased and became less than of the control. Though higher temperature increased the number of grass species, prevented weeds from teeming the land,and apparently extended the plant growing period,and raised the biomass,the heat accelerated the growth and maturing of plants, thus shortening the growing period actually.Moreover, the glass of the greenhouse retarded the fluctuation of temperature of daytime and the night time,and restricted the accumulation of dry matter.all this leads to the decrease of biomass in the greenhouse.The micro-climatic change of soil structure which also changes the structure of the plant species and leads to the species succession process.Consequently,global warming not only affects the plant productivity,but the succession of plant types as well.

The development of alfalfa floral organs is studied in detail by Scanning Electron Microscope. Results show that eight developmental stages (S1~S8) of floral organ are observed under the electron microscope. The differentiation of primary inflorescence meristem (I1) and secondary inflorescence meristem (I2) are found in S1. I2 grows into flower meristem (F) and the bracts (Br) in following S2. Single sepal primordium (Sab) appears in S3 then differentiates into carpel primordial (C) and common primordium in S4. Common primordium differentiates into petal primordium(P) and stamen primordium in S5. Sepal starts elongation in S6 then covers other flower primordials and both sides of the stamen primordia (STs) as well as stamen primordia (STp) which is close to the carpel and is beginning to differentiate into stamens. Vexillum and alae petals differentiate obviously, keel petals begin to fuse, stigma collapses in immature stamen and stamen differentiates clearly in S7. Entire flower development is completed, stigma begins to stretch and anther becomes mature in S8. The stamen primordium of Huaiyin alfalfa produces original winged-shaped anthers, and the pollen grains belong to type N3P4C5. This study not only lays a foundation for the research of alfalfa male sterility, self-incompatibility, flower development mode, anther culture and flower mutant fertility, but also provides guidance to molecular biology and developmental genetics of alfalfa floral development.

Beipan River (BPR) Grand Canyon National Wetland Park was taken as the research object. The influences of land use change due to wetland park construction on the ecosystem service value were discussed using field survey and ArcGIS as the research methods. Meanwhile, the key factors which can influence the ecosystem service value were analyzed through sensitivity analysis. The results showed that woodland area increased in large while arable land and other land area decreased in the study area after the implementation of the wetland park planning. The change of land area caused the value increase of total ecosystem service from 155.20 million yuan to 168.57 million yuan. The results of sensitivity analyses were less than 1, indicating that the ecosystem service value was robustness.

The ion absorption and distribution of reed canarygrass under salt stress(300 mmol·L^-1 NaCl) were studied using pot sand culture experiment under a rain shelter for understanding the changes of K⁺, Na⁺, Mg²⁺, Ca²⁺ and Cl^- contents and the correlations between ion contents and different NPK levels. The results showed that the contents of K⁺, Mg²⁺ and Ca²⁺ increased and the contents of Na⁺ and Cl^- decreased in reed canarygrass seedling under salinity stress. The ratios of K⁺/Na⁺, Mg²⁺/Na⁺ and Ca²⁺/Na⁺ increased with the increase of NPK fertilizer level. The Na⁺ content of reed canarygrass was a significant negative correlation with NPK level, whereas the K⁺ and Mg²⁺ content of reed canarygrass was a significant positive correlation with NPK level (P<0.05). Nitrogen fertilizer had the most significant effect on the K⁺, Na⁺, Mg²⁺, Ca²⁺ and Cl^- contents of reed canarygrass compared with others. Potassium fertilizer had more effect on the Cl^- and Mg²⁺contents of reed canarygrass,whereas phosphate fertilizer had more effect on the Ca²⁺ and Mg²⁺contents of reed canarygrass than others.

Grassland degradation and desertification is increasingly serious due to the excessive use of grassland in China. Its ecological environment is increasingly fragile and challenges the living standards of pastoralists. Ecological management and conservation projects introduced by government are increasing and the ecological compensation mechanism of grassland has additional attention. In this article, grassland resources and the living status of people in the Xianghuang Banner of Inner Mongolia were investigated based on present ecological compensation principles and subsidy policies. Results showed that ecological compensation was currently necessary and reasonable but local farmers need more subsidies to maintain their index of living. The impacts of social and economic conditions on ecological environment should be further emphasized in order to protect and enhance the benefits of farmers as corresponding grassland ecological compensation measures were formulated.

In order to reveal the stomatal response of Alfalfa under water stress,leaf water potential,transpiration rate( T_r),stomatal conductance( G_s) of alfalfa( Medicago sativa) and their relationship under water stress are studied by adopting pot-cultivation designs.Results show that the leaf water potential, T_r and G_s of alfalfa decreased with water stress increasing.The daily change of the leaf potential,Trand G_s display a bimodal curve pattern with the same mean value.The maximum is obtained under full water supply,followed by light water stress,moderate water stress and severe water stress.The lowest leaf water potential decreases with the decreasing of soil moisture,the peak appearing time of leaf potential and Trunder moderate and severe water stress is earlier than that of full water supply and light water stress.Under moderate and severe water stress,when the water potential was-4.68 MPa,or T_r was 3.27 g·m ^-2·h ^-1,the stomata begin to close.Under full water supply and light water stress,Tr increases with the decreasing water potential,and Gs increases with the increasing of T_r.The leaf water potential changes not only related with the soil moisture,but also closely related with the leaf development.

The yield and functional composition of Hedysarum polybotrys Hand.-Mazz. between different years and different slope aspects were compared and analyzed in the Wudu county of Gansu provice. Ultraviolet spectrophotometry was used to determine flavonoid contents combined with the phenol-sulfuric method to determine polysaccharide contents. Results showed that growth years and slope aspects had significant influence on yield and quality. The yield and quality of Hedysarum polybotrys cultivated in semi-sunny slopes was different between each tested year. The root dry weight and contents of both flavonoids and polysaccharides in the second growth year were 4.41, 1.26, and 1.26 times of that in the first growth year; the third growth year were 1.36, 1.53 and 1.14 times of that in the second growth year, and the fourth growth year were 1.22, 0.91 and 1.01 times of that in the third growth year, respectively. In the second growth year, the root dry weight and the contents of flavonoids and polysaccharides cultivated in sunny slope were 1.09, 1.26 and 1.10 times of that cultivated in semi-sunny slope. In the fourth growth year, the root dry weight and the content of flavonoids and polysaccharides natural growing in sunny slope were 1.49, 1.30 and 1.12 times of that natural growing in semi-sunny slope. Comprehensive analysis indicated that growth years and environment had significant effects on the yield and quality of Hedysarum polybotrys cultivated on Micang Mountain in the Wudu county of Gansu province, and the suitable growth years should be three years, the appropriate cropland should be sunny slope. In addition, there was significant correlation between the yield, quality and the root diameter, root length of Hedysarum polybotrys cultivated in semi-sunny slope. The root diameter and length of Hedysarum polybotrys can be used as a sensory basis to classify Hedysarum polybotrys Hand.-Mazz. in the actual production.

The optimum media and formulas of representative strains Sinorhizobium meliloti ACCC17631 and ACCC17676 were confirmed by single factor carbon source and nitrogen source utilization experiment and orthogonal design experiment. Results showed that the optimum carbon source was sucrose,and the optimum nitrogen source was yeast extract and soybean meal. The optimum medium formulas of ACCC17631 (ACCC17676) was (g 稬 ^-1):sucrose 20 + soybean meal (yeast extract) 2.4+K ₂HPO ₄ 0.25+KH ₂PO ₄ 0.25+MgSO ₄?7H ₂O 0.2+NaCl 0.1, and pH 6.8~7.0.

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.