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To provide a scientific basis for the sustainable utilization of grassland resources and grass-livestock balance in the Maqu alpine meadow, this study used remote sensing technology combined with field-measured data and MODIS image data in the same period in 2016. Regression models of aboveground biomass and vegetation index (NDVI) with relative grazing intensity were established individually in the study area, and a power regression model between different relative grazing intensities and NDVI was additionally established. The result showed that with increase in NDVI, aboveground biomass increased in June, July, August, and September. Ground biomass and relative grazing intensity showed optimum significant negative correlation (R2=0.965 1), which was a power curvilinear regression. Relative grazing intensity and vegetation index showed good correlation (R2=0.631); with decrease in NDVI, relative grazing intensity increased gradually. When relative grazing intensity increased to a certain extent, NDVI was not sensitive to its response.
We constructed an inversion model of the vegetation coverage of the alpine prairie in Bayanbulak, screening for the best model and checking its accuracy, which will provide a scientific basis for carrying out grassland monitoring and scientific management in the alpine prairie of Bayanbulak in future. An empirical regression model and pixel dichotomy were used to calculate the vegetation coverage and vegetation indices and to construct the inversion model. The results showed that there were significant positive correlations between the vegetation indices, except for the Modified Soil Adjusted Vegetation Index (MSAVI), and vegetation coverage (P<0.01). The best inversion model of alpine steppe vegetation coverage in Bayanbulak is the quadratic polynomial regression model of NDVI:y=-0.894x2+1.467x+0.099 (R2=0.723); its inversion accuracy is higher (R2=0.837), and can be used to estimate the vegetation coverage of Bayanbulak alpine steppes.
The Three-River Headwaters Region, located in the hinterland of the Qinghai-Tibet Plateau, contains the headstreams of the Yangtze River, Yellow River, and Lancang River. It is an important area for water conservation and protection of ecological functions in China. To analyze the dynamics of the Three-River Headwaters Region, a back propagation artificial neural network (BP-ANN) was used to simulate the grassland aboveground biomass (AGB). The grassland AGB was estimated from 2001 to 2016, and the characteristics of the temporal and spatial changes of the grassland AGB from different grassland types and river basins were analyzed. The results showed that: 1) The CXYN model based on BP-ANN is suitable for grassland biomass inversion (R2=0.769 9,RMSE=429.1 kg·ha-1); 2) In the past 16 years, the grassland AGB, overall, tended to be stable and restored; 3) The spatial distribution of AGB included significant regional differences, with a decreasing trend from the southeast to the northwest. The AGB was up to 3 000 kg·ha-1 in some parts of the southeast, but was very low (less than 500 kg·ha-1) in some parts of the northwest.
Alcohols are an important class of biomarker and are widely used to trace the source of organic matter in soil and sediments. The present study was conducted to investigate the alcohol compositions of typical alpine meadows. The samples of alpine meadow plants and soil were collected, and gas chromatography-mass spectrometry (GC-MS) analyses were carried out. The results showed that the range of alcohol types in the alpine meadow was from 2 to 21, the carbon number was from 4 to 37,and the number of unsaturated alcohols was higher than that of saturated alcohols. 9-Methyl-Z-10-pentadecen-1-ol, (3,5)-2-methylene-Cholestan-3-ol, and 1-Heptatriacotanol were not detected in the non-degraded soil,but were found in the degraded soil. The species of plant and soil alcohols in alpine meadow were as follows: degraded plants > degraded soil > non-degraded plants > non-degraded soil. There was a strong correlation between the alcohols in the plants and those found in the soil (R2=0.871).The distribution characteristics and correlation analysis of plants and soil alcohols showed that alcohols could be used as markers to indicate the degradation of alpine meadow.
We studied the response of desert community characteristics to fencing in different climatic zones, which was aimed at providing certain basic information and scientific basis for the rational utilization of grassland resources. Seriphidium transiliense deserts in Xinyuan and Hutubi counties were selected as the research areas, and the eco-economic group, community characteristics, and its diversity were analyzed using a field-survey sampling method. The results showed that: 1) The height, cover, density, and biomass of the grassland community increased significantly, which was significantly higher than those outside the fence; 2) Under the fence, Pielou’s evenness index of grassland communities increased, while the fragrant index and Patrick index decreased, and the desert vegetation comprising S. transiliense recovered remarkably.
The study of soil seed banks is of great significance in the ecological restoration of grasslands. We investigated the density characteristics, species diversity, and similarity to the aboveground vegetation of the soil seed bank, and the characteristics of seed and soil factors using a canonical correspondence analysis (CCA) model for the 0-5, 5-10, and 10-15 cm soil layers under different restoration measures in a typical steppe grassland in Ningxia. We selected sites that had been subject to enclosure for 15 years (F15), contour trenching for 1 year (S1), contour trenching for 3 years (S3), contour trenching for 6 years (S6), contour trenching for 10 years (S10), or contour trenching for 15 years (S15); grazed grassland (F0) was used as a control. The results showed that 1) The number of plant species was the highest in S1, followed by that in F15, and the lowest in F0 and S10. There were no significant differences in seed bank plant species with increasing years, but the seed bank constituents shifted from annuals to perennials. 2) The density of the soil seed bank was the highest in F15, intermediate in S3 and S15, and the lowest in F0. The density of the soil seed banks was characterized using table clustering. With the increase in the duration of contour trenching, the total seed bank showed an up-down-up trend. 3) The similarity coefficient between the seed bank and aboveground vegetation in the various treatments was generally low, at 0.380.55. F15 had the highest similarity with S3, and the lowest with S10 and S15. 4) CCA showed that soil available potassium, moisture content soil total phosphorus , and were the main factors affecting the distribution of soil seed banks in this area. Our study showed that, compared with grazed grassland, restoration through contour trenching can increase the number of species and density of soil seed banks in a typical grassland, but the effect is still lower than that of enclosing the grassland.
The aim of this study was to explore the response of community characteristics and plant diversity, in deserts in different regions, to grazing exclusion (GE), and to analyze the effects of GE on community stability. The research was carried out in the Artemisia desert on the northern slopes of the Tianshan Mountains, where the community characteristics were measured and studied. The results showed that 1) GE altered the functional group structure of the desert community in different regions and that community coverage and biomass after GE increased significantly by 40.2%57.0% and 44.4%81.0%; 2) the response of the desert plant diversity indexes to short-term GE were weak, however, the Patrick and Shannon-Wiener indexes of the grazed area in the Manasi desert were significantly higher by 16.720.0% than in Qitai and Bole, and the Simpson and Shannon-Wiener indexes of the GE area were significantly higher by 8.6%17.7%; 3) short-term GE can maintain the stability of desert communities, and the stability is related to GE times and ecological factors. Therefore, short-term GE can significantly improve desert grassland productivity, and maintain vegetation diversity and community stability.
In order to study the effects of long-term grazing and short-term rainfall variations on vegetation characteristics of a grassland ecosystem, an experiment using different rainfall gradients (50% reduction, ambient, 50% increase, and 100% increase in environmental rainfall) was conducted on the site of a long-term manipulative stocking rate experiment (no grazing, light grazing, moderate grazing, and heavy grazing), and the response (in terms of individual quantities, species diversity and aboveground biomass of the plant community) to rainfall changes was analyzed. The results showed that: 1) variations in long-term grazing and short-term rainfall had significant effects on community coverage (P<0.05) (community coverage decreased with increasing grazing intensities but increased with increasing rainfall); 2) the rainfall variations had significant effects on species diversity (P<0.05) (there was an increase of 22 species with 100% increase in environmental rainfall under moderate grazing conditions); 3) the long-term grazing and short-term rainfall variations had significant effects on aboveground biomass (P<0.05) (The highest aboveground biomass was 408.3 g·m-2 under ambient rainfall under no-grazing conditions, and the lowest aboveground biomass was 118.2 g·m-2 with 50% reduction in environmental rainfall in heavy grazing conditions).
Because of the influence of global change and external disturbances, habitats of alpine meadows are trending toward aridification in the Qinghai-Tibetan Plateau. How would variation in habitat affect the elevational pattern of species diversity? Nine sample plots were set along an elevational gradient in the Dongda Mountains in southeast Tibet. Ten 1 m×1 m sample quadrats were set in each sample plot, with five quadrats located in wet habitat and the others located in dry habitat. Species composition in each quadrat was investigated. Species with a frequency lower than seven were defined as occasional species; otherwise, the species were common. For total occasional and common species, variation of α, β, and γ diversity were respectively analyzed along the elevational gradient. β diversity was measured by the Cody index (βc), multiplicative partitioning (βw), and the slope of regression between similarity of species composition and distance (βslope). There were 160 seed plants recorded in these sample plots, among which, 132 species were distributed in wet habitats and 107 species in dry habitats. For total and occasional species, α and γ diversity both decreased with elevational gain in wet habitats but increased in dry habitats. For common species, α and γ diversity both presented an increasing trend with elevational gain in wet and dry habitats. The elevational patterns of β indexes were not consistent,βc and βw in wet habitats were higher than that in dry habitats, and βc and βw of occasional species was higher than that of common species. The elevational patterns of species diversity between wet and dry habitats were different, and diversity of occasional species had a high value, and will directly affect elevational patterns of species diversity.
Northern grassland is an important livestock production base in China, as well as being an important ecological barrier in northern China. To determine the overall situation, spatial distribution, and dynamic change of northern grassland resources, we designed and developed the Northern Grassland Resource Management Information System based on ArcGIS Server 10.0 and Microsoft SQL Server 2008, which combined the Flex framework and WebGIS technology. A comprehensive, accurate, and efficient monitoring information management platform for grassland resources can quickly browse, query, and manage the northern grassland resources. Such a system provides scientific and rational data to relevant decision makers and promotes the development of the digital grass industry in China.
Climate is a dynamic combination of environmental factors that can affect lawn development and the turfgrass industry in China. In this study, six meteorological indexes, namely average annual temperature, average annual precipitation, July average temperature, January average temperature, July humidity, and January humidity were selected as indexes of ecological, climatic regionalization for lawns, and a lawn climate zoning map was completed by ArcGIS software. In the study, we divided China into nine eco-climatic zones for lawns, including the Qinghai-Tibet Plateau zone, Cool-semiarid zone, Cool-humid zone, Cool-arid zone, Northern transitional zone, Yunnan-Guizhou Plateau zone, Southern transitional zone, Warm-humid zone, and the Tropical and subtropical zone. The Yunnan-Guizhou plateau zone, the Warm-humid zone, and the Tropical and subtropical zone are the most suitable for warm-season turfgrasses, while the Cool-humid zone is suitable for cool-season turfgrasses. Turfgrass drought resistance is required for the development of the turfgrass industry in the Qinghai-Xizang plateau zone, Cold-semiarid zone, and Cool-arid zone. For the North and South transitional zones, the cultivation of excellent lawn turfgrass varieties and the development of advanced maintenance techniques are necessary.
Grass height plays a vital role in grassland degradation, desertification assessment, remote-sensing monitoring of grassland aboveground biomass, and monitoring of pastureland snow disasters. However, highly accurate monitoring and mapping of grass height has always been a difficult issue in grassland remote-sensing research. In recent years, the continuous development of multispectral remote sensing, LiDAR remote sensing technology, unmanned aerial vehicles, and hyperspectral remote sensing technology has provided technical support for high-precision remote-sensing monitoring of grass height. Based on the review of remote-sensing monitoring of grass height, this paper summarizes the existing problems and prospects of grass height remote-sensing monitoring to provide assistance for high-precision remote-sensing monitoring of grass height.
Anoectochilus roxburghii is an herbaceous plant which is used as a Chinese herbal medicine and ornamental plant, with high economic and medicinal value. In this paper, the recent studies of tissue culture techniques of A. roxburghii are summarized regarding explant selection, minimal medium usage, induction of callus and bud, multiplication culture, and influencing factors. Seeds, nodal segments, stem apices, stems, and leaves are commonly used as explants for tissue cultures of A. roxburghii. Tissue culturing and regeneration of this species mainly relies on three approaches: Firstly, by using a protocorm-like body, with hormones and genotypes being the main influencing factors; secondly, culturing by differentiation from stem segments into buds, with cytokinin and auxin having synergistic effects; and thirdly, by callus differentiation, using the stem pieces and stem segments, as the explants can differentiate into a large number of adventitious buds; here, 6-BA plays a crucial role. In general, light conditions and natural organic matter are important factors to consider in the tissue culture of A. roxburghii. The aim of this paper is to provide an evidence-based protocol for rapid propagation of A. roxburghii, as well as to lay a foundation for protection, utilization and industrialization of A. roxburghii.
Alfalfa is the most-cultivated and most widely used forage legume in the world. Its moderate salt tolerance limits its cultivation and production in Northern China because of the soil salinization in this area. Therefore, improving alfalfa salt tolerance is important for both scientific research and commercial production. In this study, we used Medicago sativa ‘Longmu 801’ as a model to analyze the expression patterns of 9 salt response genes selected for salt stress proteomics using quantitative real-time PCR under various NaCl concentrations. The results showed that time and NaCl concentration had significant effects on the relative expression of all 9 genes, indicating that these 9 genes play roles in alfalfa’s salt stress response. The relative expression levels of G6PI, ABP19a, Trx-h1, PR bet 1, FBPA, 6PGDH, and ALDH genes were all significantly up-regulated in alfalfa treated with the tested NaCl stress concentrations for 1 h. RRM and GDPD were obviously up-regulated after 2 h of NaCl treatment. Except G6PI, the relative expression of the remaining 8 genes under 0.4% NaCl stress was much higher than that under 0.2% and 0.8% NaCl stress. These genes are mostly involved in carbohydrate metabolism, signal transduction, and stress response. This result demonstrated that alfalfa’s salt tolerance is complicated and is a result of multi-gene expression and the interactions of many metabolic pathways. This result is useful for further research on alfalfa salt response genes and selective breeding of alfalfa using molecular markers.
In this study, alfalfa CMS MS-GN-1A was used as the female parent, and the restorer line MS 178 was used as the male parent to construct BSA separate groups. All products of F1 were male fertile. There were 221 plants in the F2, and the number of sterile plants was 57, with 164 fertile, and no semi-sterile plants were found. Based on the results of the fertility microscopy, the separate population was divided into two groups, fertile and sterile group; the genomic DNA of the fertile and sterile groups were extracted and 20 samples of DNA from each group were randomly selected and mixed into a fertile and sterile gene pool for the positioning of restoring genes. The experiment randomly selected 160 pairs of known tetraploid alfalfa SSR primers. To amplify the gene pool DNA, two molecular markers with polymorphism (Mt2c12 and AW166) were obtained, and were initially positioned on a composite of five primers. All primers on this group were synthesized, and the designed primers were screened again. Finally, four markers with polymorphism were obtained: BI68, Mt2c12, BG267 and AW776153, with a genetic distance of 19.0 cM, 20.9 cM, 44.6 cM, and 72.1 cM, respectively.
The agronomic characters and SRAP genetic diversity of 21 introduced male sterile lines of brown midrib forage sorghum (Sorghum bicolor) were investigated. The results showed that the stem diameter and leaf width were largest in BMP17, being 29.97 mm and 9.88 cm, respectively. The stem-leaf ratio in BMP20 was significantly higher than that in the other germplasms (P<0.05). A total of 74 bands were generated, of which 64 (86.5%) were polymorphic. The average value of polymorphic information content was 0.49. The genetic similarities among the 21 accessions ranged from 0.086 to 0.977. The dendrogram indicated that the 21 sorghum collections were grouped into three clusters at a genetic distance of 0.488. The genetic basis was narrow for the 21 sterile lines of Sorghum.
SSR markers were used to analyze the genetic diversity of 30 accessions of wild Elymus nutans collected from the Qinghai-Tibet Plateau. The results showed that: 1) A total of 116 fragments and 92 polymorphic loci were generated from 16 pairs of primers. The polymorphic loci rate (PPB) was 79.75%, with polymorphism information contents (PIC) ranging from 0.063 to 0.325 (mean 0.188). The genetic similarity (GS) coefficient ranged from 0.692 to 0.976 (mean 0.828). 2) A cluster analysis showed that at the genetic similarity coefficient of 0.804, the 30 samples clustered in four major groups. Individually clustered groups of 09-214 showed distant genetic relationships with other accessions. The result of a principal component analysis was generally consistent with those of a UPGMA. The analysis of population genetic structure indicated that most of the samples may originate from the same genetic background, and results of grouping analysis were consistent with those of the cluster analysis. Our results showed a great difference between the tested germplasm samples, with several of the accessions showing relatively independent characteristics and higher genetic diversity, which could provide reference for the protection and utilization of E. nutans, the selection of new varieties and the discovery of “good genes”.
The establishment of a regeneration system using the anther tissue culture method is an important approach in haploid breeding. In the present study, the anther tissue culture of Medicago falcata ‘Hulunbeier’ was investigated and the regeneration system of anther tissue culture established. The results showed that liquid suspension medium was more suitable than solid medium for M. falcata in the induction of anther callus. Mixtures of B5+0.5 mg·L-1 2,4-D+0.25 mg·L-1 6-BA+0.4 mg·L-1 NAA+3.0 mg·L-1 KT, MS+1 mg·L-1 2,4-D+0.5 mg·L-1 6-BA+sucrose 2%+ager 0.7%, and 1/2 MS+0.1 mg·L-1 NAA+sucrose 2%+ager 0.7% were suitable for callus induction, callus differentiation, and rooting culture, respectively. The percentage of haploids of regenerated plants was measured by flow cytometry as being 27% for M. falcata.
Ascochyta onobrychis is the causal pathogenic microorganism of sainfoin leaf spot and black stem, which is a serious disease. A strain of microorganism that has strong antagonistic activity against A. onobrychis was obtained when the pathogen was isolated. To evaluate the exploitation and foreground of the antagonistic microorganism, the present study identified the taxonomic position of the strain by morphological, molecular, and biochemical methods, as well as determined the inhibitory effect of the strain against A. onobrychis. Based on its morphological characteristics, both physiological and biochemical, together with 16S rDNA sequence analysis, the strain was identified as Streptomyces albidoflavus. The colonies ware yellowish white in color on Gause’s agar and produced yellowish white water-soluble pigments and a mycelium hook-like top spiral. The relative inhibition rate to the pathogen was 74.33% that was measured with the dural culture method. The actinomycetes sterile fermentation broth had a strong effect on mycelial growth and spore germination, with inhibitory rates of 80.95% and 93.87%, respectively. The results showed that the actinomycetes had potential value in the biological control of A. onobrychis.
A water controlling experiment was carried out to determine the effect of drought stress on physiological indexes of five kinds of forage grasses which inclueded Agropyron mongolicum, A. cristatum×A. desertorum, A. desertorum, Psathyrostachys juncea and Bromus inermis by adopting pot culture method. Chlorophyll contents, membrane permeability, proline contents, superoxide dismutase(SOD), peroxidase(POD) and catalase(CAT) activity, and malondialdehyde(MDA) contents were measured at different stage of the drought stress. The drought resistances of the five kinds of forage grasses were comprehensively evaluated by using subjection function method. The results showed that as the extension of drought stress period, the relative water content(RWC) decreased, the water saturation deficit(WSD), cell membrane permeability of the seedlings for the five grasses generally increased. The proline contents, chlorophyll contents, SOD, CAT and POD activity showed as increase-decrease trends. The MDA contents showed as increase-decrease-increase trends. The mean value of membership functions of the five grasses ranged from 0.351 0 to 0.688 1, and the drought resistance of the seedling period showed as: Agropyron desertorum>Psathyrostachys juncea>A. cristatum×A. desertorum>A. mongolicum>Bromus inermis.
A field experiment was conducted to analyze the heritability and combining ability of the 7 main agronomic traits from 57 hybridized combinations of brown midrib (BMR) sorghum sterile lines using NCⅡ incomplete diallel cross design. A total of 19 BMR Sorghum sterile lines and 3 BMR sudan grass lines with independent breeding were used as female and male parents, respectively. The results showed that four agronomic indexes (plant height, leaf number, middle leaf length, and middle leaf width) had mid parent heterosis. Plant height and middle leaf length showed high parent heterosis; leaf number, middle leaf length, and middle leaf width expressed competitive heterosis; whereas tiller number, stem diameter, and panicle length showed negative heterosis. There were no significant differences in the blocks among the main agronomic traits (P>0.05), yet there was a significant difference in the combination (P<0.01). The stem diameter and main panicle length were controlled by both additive and non-additive effects, whereas non-additive effects were very strong in plant height, leaf number, middle leaf length, and middle leaf width. The main stem length should be selected during the early stage, whereas the other traits should be selected during the later stages except for the middle leaf width that was affected by environmental conditions. Based on the comprehensive analysis, the general combining ability of BMR sorghum sterile lines AMP454, AMP19, and T98A were relatively high, with the better hybrid combinations being AMP19×ZS-102 and AMP454×ZS-102.
In order to find the optimal chlorocholine chlorid (CCC) concentration for enhancing lodging resistance and seed yield of rye, the effects of different CCC concentrations (0, 0.1%, 0.2%, 0.3% and 0.4%) were tested in this study. The main results were as follows: at CCC concentrations of 0.3%, and 0.4%, plant height decreased by about 30 cm, on average, and internode length was shortened. The outer diameter, bending resistance, potassium content,soluble sugars, and the lodging resistance index of the second internode increased, whereas nitrogen content decreased. Furthermore, rye seed yields of the 0.3% and 0.4% treatment groups were significantly higher than those of the control groups(without CCC). Seed yield of rye was significantly correlated with plant height, outer diameter, potassium (K) and nitrogen (N) content in the second internode at 0.01 level, and 0.05 level, respectively, which showed that the enhancing of lodging resistance was important for increased seed yield. No significant effects of CCC concentrations of 0.1% and 0.2% were observed. From the point of economy and environmental protection, 0.3% CCC seems to be the optimal concentration due to increased yield at the lowest amount used. This study contributes to eliminating problems related to low seed yield due to the excessive plant height and softness of the stem, which is essential for high seed production in rye.
Freezing injury is the main limiting factor for alfalfa in northeast China. The screening of breeding materials that can resist freeze-thaw stress is of great significance for improving the yield and quality of alfalfa. In the present study, five different combinations of alfalfa (Medicago sativa) were selected as test materials, which were subjected to three different treatment stages: cold resistance training stage, freezing stage, and turning green stage. soluble protein(SP), soluble sugar(SS), proline(Pro), and malondialdehyde (MDA) contents, and superoxide dismutase (SOD) activity were measured. The results showed that the SP content had an overall increasing trend and was significantly higher in each test material than in the control group. The SS content fluctuated and was significantly lower in all test materials than in the control group during the cold resistant stage. The SS content was significantly higher in all test materials than the control group during the frozen stage, and the Pro content generally increased. MDA contents in the Ⅱ, Ⅲ, and Ⅴ hybrid combinations were lower than that in the control group, although this difference was not significant. SOD activities first increased and then decreased,with the contents during the other phases significantly higher than that in the control group. Membership function analysis showed that the order of cold resistance in the hybrid combinations was Ⅴ>Ⅲ>Ⅰ>Ⅱ>Ⅳ.
DUS testing provides a technical and authoritative basis for the protection of new plant varieties. Ten zoysiagrass varieties, including two candidate varieties, two similar varieties, and standard varieties, were selectedin the present study for DUS testing over two consecutive growing seasons. The test was strictly guided by DUS testing guidelines, published by the Ministry of Agriculture of China. The distinctness of eight quantitative characteristics were assessed by two methods (note and statistical analysis) to provide practical evidence for the assessment of quantitative characteristics of zoysiagrass DUS testing. The assessment of results from the two methods showed that quantitative characteristics with distinctness that were assessed by the notemethod showed non-significant differences by the statistical analysis method, whereas characteristics without distinctness showed significant differences by the statistical analysis method.To avoid such misjudgment of distinctness, the quantitative characteristics with distinctness assessed by the notemethod were further analyzed with the statistical analysis method. The results showed that the candidate variety of zoysiagrass Guanglü had distinctness in quantitative characteristics of stolon length of internode, leaf length, and seed kilo grain weight, whereas the candidate variety of zoysiagrass Z0413-1 had distinctness in quantitative characteristics of stolon length of internode, leaf width, and inflorescence numbers of spikelet.
Reclaimed and tap water mixed irrigation experiments on feed sweet sorghum (Sorghum dochna) were conducted in the Ordos region. The effect of using a water-retaining agent (30 kg·ha-1) under 75% and 50% of the normal irrigation amount were studied, and the yield, crude protein, neutral detergent fiber, acid detergent fiber, and soluble sugar contents were compared to determine the most efficient ratio of reclaimed and tap water irrigation. The result showed that under 75% normal irrigation (+PAM), the yield of sweet sorghum (26.89 t·ha-1) was 39.68% higher than that under the ratio of reclaimed and tap water and pure tap water irrigation of 2∶1. Compared with the 1∶1 irrigation ratio of reclaimed and tap water with only tap water irrigation, the CP and SS contents increased by 9.7% and 12.9%, respectively, whereas the NDF and ADF contents decreased by 4.8% and 7.3%, respectively.
To investigate the most appropriate water and fertilizer management system for Cichorium intybus, an orthogonal design was used to undertake a three level experiment with four factors: soil moisture content (20%, 30%, and 40%), nitrogenous fertilizer (300, 500, and 700 kg·ha-1), phosphate fertilizer (300, 450, and 600 kg·ha-1), and potash fertilizer (100, 150, and 200 kg·ha-1) to study the influence of different water and fertilizer treatments on the yield and quality of C. intybus. The results showed that fresh grass yields of C. intybus were significantly (P<0.05) increased in the different water and fertilizer treatments and the annual yield ranged from 7.93×104 kg·ha-1 to 1.997×105 kg·ha-1, reaching its maximum (1.997×105 kg·ha-1) in the combined application of 40% soil moisture content, 500 kg·ha-1 nitrogenous fertilizer, 300 kg·ha-1 phosphate fertilizer, and 200 kg·ha-1 potash fertilizer, which increased yield by 60% to 300% compared to that of the control (4.97×104 kg·ha-1). In terms of quality of C. intybus, crude protein content significantly increased in all the different water and fertilizer treatments, and reached a maximum of 294.1 g·kg-1 in the treatment of 30% soil moisture content, 500 kg·ha-1 nitrogenous fertilizer, 600 kg·ha-1 phosphate fertilizer, and 100 kg·ha-1 potash fertilizer, which increased the crude protein content more than twice that of the control treatment. The above water and fertilizer conditions provide production guidance for high yield and high protein C. intybus forage cultivation in Guizhou and provide forage source and guarantee the rapid development of animal husbandry in Guizhou Province.
Broussonetia papyrifera is a woody plant species in the family Moraceae, and due to its high protein content is widely used in the feed industry in southwest China. To examine the differences in drying methods for hay production, we investigated water loss rates and nutritional value of B. papyrifera as an example to optimize the available technologies to achieve preservation of nutrients for substituting succulent feeds or concentrates. In the article, we present the results of cluster analysis of 23 drying methods, sub-divided into three groups: quick drying, medium-speed drying, and slow drying. Water loss rate could be improved in small stacks, and the fastest way of drying was squashing and cutting the plant material to a length of 10 cm. Based on calculated feeding values of a factor analysis, we found that the optimal method was cutting of plant material to 10 cm pieces and applying a 2% K2CO3 treatment, achieving a score of 0.514. When the stem structure was destroyed by applying a treatment of spraying K2CO3, the cutting method further decreased the superficial area of the vascular bundle, which enhanced the feeding value.
Individual plants can react to grazing of different intensities with a variety of adaptions, including trade-offs of several functional traits. In order to study the responses of Cleistogenes songorica individual traits to long-term grazing, this study, conducted in a desert steppe (Inner Mongolia), focused on the individual functional traits, the relationship between individual above-ground biomass and its functional traits, and the effect of the functional traits on the individual above-ground biomass in the dominant species, C. songorica. The results showed that the leaf characteristic index, individual above-ground biomass, plant height, and crow (bundle) decreased significantly with the increase of grazing intensity. Apart from basal stem diameter and average leaf length, we found positive correlations of individual above-ground biomass, stem biomass, leaf biomass and phenotypic traits of stem and leaves with grazing intensity. Furthermore, a greater variability was observed among individual above-ground biomass components, while only a relatively low correlation coefficient of phenotypic traits with smaller variability, and individual above-ground biomass components was found. Among all phenotypic traits of above-ground biomass of C. songorica, the VIP (variable importance projection) of total leaf area, the total number of leaves, and the average leaf length was greater than 1, and its contribution rate to individual aboveground biomass approached 61.01%. Grazing resulted in significant difference among all functional traits of C. songorica, however, grazing pressure did not challenge its position as a dominant species in this desert steppe.
In the present study, two photoperiod-sensitive (Sorghum bicolor×S. sudanense), ‘Big Kahuna’ and ‘Monster’, were planted in the rainfed region of the loess plateau at three different planting densities (83 300, 125 000, and 166 700 plants per hectare) by dibbling with plastic film. The growth and development indices and yields of each hybrid were measured and compared. The results showed that for the growth duration, there was a significant difference between the two hybrids after the booting stage. For the agronomic characters, the numbers of tiller and whole plant leaves of ‘Monster’ were higher than that of ‘Big Kahuna’, whereas the other characters of ‘Big Kahun’ were higher than that of ‘Monster’. Stem diameter, tiller number, whole plant leaf number, internode number, and leaves and stem weights per plant of the two hybrids decreased under increasing planting density over the 2 years with a negative correlation. The leaf number of the main culm showed a trend of first increasing and then decreasing with increased density. The fresh grass and dry matter yields of ‘Big Kahuna’ were higher than that of ‘Monster’ over the 2 years and the fresh yield in the 83 000 plants per hectare density was the highest of the three densities and tended to decrease with an increase in density. The dry matter yield in the 166 700 plants per hectare density was higher than that of the other densities during 2014, which experienced abundant rainfall, whereas the yield in the 125 000 plants per hectare density was higher than that of the other densities during the 2015 drought. In conclusion, when photoperiod-sensitive S. sudangrass hybrid are planted in a rainfed region of the loess plateau by dibbling with plastic film, ‘Big Kahuna’ should be chosen at a density of 166 700 plants per hectare in an area with good irrigation conditions or precipitation, otherwise a density of 125 000 plants per hectare should be planted.
Twenty-one species of brown midrib forage Sorghum were used to evaluate drought and salt resistance during germination and seedling stagesusing PEG-6000 and NaCl. The results showed that low concentrations of drought and salt stress could promote the germination rate, root length, bud length, and vigor index of the more resistant materials.Catalase(CAT) cactivity under PEG-6000 and NaCl stress conditions increased during the seedling stage, whereas the superoxide dismutase (SOD) and peroxidase (POD) initially increased and then decreased. BMP12, BMP456, and BMP448 had stronger resistance to drought during both germination and seedling stages than that of the other species. BMP16, BMP12, and BMP453 had stronger resistance to salt during both the germination and seedling stages than that of the other species.
To select the best oats (Avena sativa) suitable for planting in the north-western Sichuan region, we assessed the phenological phase, plant height, stem diameter, hay yield, fresh weight/dry weight (FW/DW) ratio, proportion of stem, leaf and ear, and nutrient content (crude protein, ether extract, crude ash, neutral detergent fiber, and acid detergent fiber) among six oat cultivars (Qinghai No.444, Qingyin No.1, Lean, Dingyan No.2, Ogle, and Monida). Results showed that all oat varieties completed their life cycles except for Dingyan No.2. Qinghai No.444 and Qingyin No. 1 experienced the shortest growth period, 130 and 133 d, respectively. Plant heights of the tested oats ranged from 81.53 to 90.54 cm (P>0.05). The stem diameter of Monida was the largest at 4.35 mm, whereas Qingyin No.1 was the smallest at 3.32 mm. The hay yield of Lean was the highest (10 448.52 kg·ha-1), whereas Qingyin No.1 was the lowest (8 554.81 kg·ha-1). The FW/DW ratios of Qinghai No.444 and Qingyin No.1 were lower than that of the other varieties (P<0.05). Lean had higher leaf and ear proportions than that of the other cultivars. The crude protein content of Lean was 7.82%, which was higher than that of the other oats, whereas Dingyan No.2 had the lowest content (5.83%). The ether extract content of Qingyin No.1 was 2.93%, which was higher than that of the other oat cultivars, whereas Ogle was the lowest at 2.48%. The crude ash, neutral detergent fiber, and acid detergent fiber content of Qinghai No. 444 was the highest, being 4.60%, 35.57%, and 63.27%, respectively. Dingyan No.2 was the lowest among the other oat cultivars, being 3.76%, 32.00%, and 54.47%. Based on results from the comprehensive evaluation analysis, Lean and Monida were the most suitable cultivars for promotion in the north-western Sichuan region.
Suberin is a biopolyester based on glyceride-phenols and contains two domains, polyaliphatic and polyaromatic. Typical polyaliphatic polyesters include ω-hydroxy fatty acids, α,ω-dicarboxylic acids, fatty acids, and primary alcohols, with ferulic acid being the main component of polyaromatics. Suberin is usually deposited in the cell walls of certain tissues, such as root endodermis, root exodermis, tuber peridermis, seed coats, and other boundary tissue layers of plants to form suberin lamellae. Suberin lamellae serves as a protective barrier in these tissue layers, not only controlling water and nutritional element transport, but also effectively resisting the invasion of pathogens and toxic gas. This review summarizes the distribution, chemical composition, ultrastructure, transmembrane transport, and aggregation assembly of suberin monomers in plants, focuses on the latest research progress on the synthetic pathway of suberin and its function in response to biotic and abiotic stresses in plants, and provides important theoretical references for pasture and crop improvement by changing the adaptive root structure of plants.
This study was conducted to (1) investigate the mechanism of the effects of sweet sorghum (Sorghum bicolor) on the rumen metabolism of the meat sheep and (2) provide technical support for the scientific utilization of sweet sorghum. Eight small-tailed han sheep [body weight=(26.61.1) kg] were randomly divided into two groups and were fed sweet sorghum silage (HG) and maize (Zea mays) silage (HY), respectively. The concentrate and alfalfa pellet (Medicago sativa) were fed at 1% and 0.5% of animal weight. The rumen fluid was collected on days 1 (D1), 7 (D7), and 30 (D30) of the study period. Subsequently, the pH, concentration of ammonia nitrogen (NH3-N), and volatile fatty acid (VFA) were determined. The results showed that the feed intake of corn silage (520 gd-1) was higher than that of the sweet sorghum silage (310 gd-1). There was no effect of the treatment, period, and interaction (P0.05) on the rumen pH in the two groups. However, the concentration of ammonia nitrogen (NH3-N) was affected by the treatment, period, and interaction (P0.05), and the concentration of NH3-N was the highest in D7 and lowest in D1. Furthermore, the concentration of NH3-N in HG group was significantly higher than that in HY group on D30. The content of branched fatty acids (isobutyric and isovaleric acids) were affected by the feed treatment (P0.05), the content of fatty acids of HG group was significantly higher than those of HY group on D7 and D30. The ratio of acetic acid/propionic acid (A/P) was effected by the interaction effects of feed treatment and period (P0.05), A/P of HG group was higher than that of HY group on D7; however, on D30, the result was contrary. These results suggest that there are differences in the adaptability of different silage diets in the rumen of small-tailed han sheep.
This study investigated the effects of forage sweet sorghum silage and whole corn silage on the nutrient utilization of sheep. According to the principle of similar weight, fourteen Dorper sheep (38.00±0.65 kg,♀) and fourteen small-tailed han sheep (29.83±0.94 kg,♀) formed the two study groups, respectively. They were free to consume wrapped silage (corn silage or forage sweet sorghum silage), the concentrate supplements and alfalfa granules were fed twice according to 1% and 0.5% of their body weight. The results revealed the following. 1) The apparent digestibility of ADF (acid detergent fiber) and NDF (neutral detergent fiber) in the forage sweet sorghum silage group was not significantly different from those in the corn silage group (P>0.05). Furthermore, the loss of fecal nitrogen of the forage sweet sorghum silage group was significantly lower than that of the corn silage group (P<0.01). 2) The nutrient intake, dry matter (DM), and organic matter (OM) of corn silage group were significantly higher than those of the forage sweet sorghum silage group (P<0.05). It was concluded that under the experimental condition, the proportion of non-protein nitrogen was low, while the proportion of available protein and soluble carbohydrates were high in the forage sorghum silage used for the fattening of sheep. Therefore, the forage sweet sorghum can be used as silage for safe and effective feeding.
The undigested neutral detergent fiber (uNDF) is a portion of neutral detergent fiber that cannot be fermented and utilized by the microorganisms in the rumen. However, it plays an important role in the growth and metabolism of ruminants. Therefore, optimal level of uNDF in the diet is crucial for the nutrition and health of ruminants. In this paper, we reviewed 1) the nutritional functions of uNDF, including feeding behavior, rumen function, NDF digestibility, and diet formulation; 2) uNDF determination method; 3) application of uNDF in diet formulation in order to provide reference and theoretical basis for the health and efficient production of ruminants.
Nitrogen (N) addition effects on plant and soil biota, and functional processes of terrestrial ecosystems were studied. The response of soil fauna to nitrogen addition has not yet been well studied in comparison to the studies on the response of plant communities. Here, we studied the effects of N addition on soil biota in a semi-arid steppe community in central Inner Mongolia using a field experiment. The experiment consisted of four N addition levels, applied by adding N fertilizers at four rates, including: 0 (control), 25 (low), 50 (medium), and 100 (high) kg·ha-1. After 5 years of treatments, we examined the changes in soil fauna communities and their functional groups in response to different N treatments, and analyzed their relationships with environmental factors. The results showed that N addition at the low and medium levels enhanced the abundance of soil fauna by 75.8% and 76.7%, respectively, in comparison to that of the control, where as N addition at the high rate significantly decreased the diversity of soil faunas. The responses of soil fauna to N addition varied among functional groups. The abundance of predatory and saprophagous fauna decreased by 69.1% and 54.4%, respectively, under the high N treatment; whereas the phytoplasmic and omnivorous functional groups showed no significant changes under different N treatments. The results of RDA analysis also detected a significant negative correlation between the abundance of Mesostigmata nymphs and Laelapidae and N addition rates, and the abundance of Isotomidae and Entomobryidae were indirectly affected by N addition through the effects on plant species richness, soil organic carbon, and litter pH. Our results indicated that low N addition rates may enhance the abundance of soil fauna in the litter layer of steppe ecosystems, whereas a high N addition rate [>10 g ·(m2·a)-1] may decrease the diversity of soil fauna.
The effects of different lactic acid bacteria additives on the fermentation quality and aerobic stability of oat silage was studied. The three selected strains Lactobacillus plantarum, L. rhamnosus, and L. buchneri were added to the oat silage. After 45 days of fermentation, the fermentation quality and aerobic stability of the oat silage were determined. The results showed that the three selected LAB inoculants significantly reduced the pH value, PA, and ammonia nitrogen content (P<0.05), the treatment with L. buchneri had the highest AA content (P<0.05). The lactic acid bacteria count in L. plantarum treatment was the highest among the treatments; the yeast count in the control and L. buchneri treatment was below the detectable level; molds were below the detectable level in all treatments. The treatments with L. plantarum and L. buchneri had higher residual WSC content than that of the control and L. rhamnosus treatment. The aerobic stability of control and L. buchneri treatment was >168 h. With the increase in air exposure days, the pH value of L. buchneri treatment was maintained around 4.0, and the yeast count was always lower than that of the other treatments. All three LAB inoculants improved the fermentation quality of oat silage. Furthermore, L. plantarum and L. rhamnosus decreased the aerobic stability hour of oat silage.
The aim of this study was to investigate the changes in nutritional value of four sorghum varieties of Hainiu, Big kahuna, Dajiang 3180, and Dajiang 1180 at different stages of development, in the Hexi saline-alkali area of Gansu Province. The main nutrient components, in vitro digestibility, and in vitro fermentation gas production of the four varieties during branching period, jointing stage, and heading stage were determined by proximate analysis and in vitro gas production techniques. The results showed that the height and fresh weight of the four varieties were significantly different. Furthermore, a significant increase in the height and fresh weight of the four varieties was observed (P>0.05). The results also revealed that the fresh weight and ratio of stems to leaves of Hainiu was the highest, while those of Dajiang 1180 were the lowest with prolonged harvest. Further, the crude protein content in different parts of the same species was also different, in the order stem<whole plant<leaves. The NDF and ADF decreased significantly (P<0.05). The NDF and ADF of Hainiu and Big kahuna were significantly lower at the jointing and heading stages than those of the other two cultivars. The higher NDF and ADF positively affected the relative feeding value. At the same time, the stalks, leaves, and whole plants of Hainiu and Big kahuna also contained high sugar contents. The gas production, VFA concentration, and dry matter disappearance rate of Hainiu and Big kahuna was higher than those of the other two cultivars at 72 h. There were no significant differences in the yield of methane among the four varieties. The results suggest that Hainiu and Big kahuna are the best forage varieties with high nutritional and feeding values. Thus the varieties can be recommended for large-scale planting on dry saline lands of Hexi, Gansu.
To reduce the risk of contamination of leafy vegetables with nitrite, effects of different treatments and storage time on nitrite levels were analyzed. The Chinese cabbage (Brassica pekinensis) and cabbage (B. oleracea) were used as the test materials, and fried or boiled materials were stored at 4 ℃ with or without bagging, as well as with ensiling. Ensiling were performed for 6, 12, 24 and 48 h, and 40 d, and other treatments were performed for 6,12,24 and 48 h. The results showed that pretreatment had significant effects on the levels of nitrate and nitrite in the Chinese cabbage and cabbage (P<0.05); however, bagging did not exert significant effects on the levels of nitrate and nitrite (P>0.05). After boiling and frying, the nitrite level in the leafy vegetables stored at 4 ℃ for 48 h did not increase significantly. Nitrite level decreased at the beginning of ensiling, increased significantly after 24 h (Chinese cabbage) or 12 h (cabbage), and then decreased (40 d for Chinese cabbage, 48 h for cabbage after storage). The nitrite level in the cabbage ensiled for 40 d, in particular, was lower than that in the original material (P<0.05).
To use cassava as feed effectively, the influence of ensiling time and temperature on the fermentation quality and hydrocyanic acid content in cassava roots and leaves was investigated. The results showed, as the ensiling time prolonged, pH of cassava roots and leaves decreased, and they were 3.73 and 4.70 at 56 d, respectively. Lactic acid content of roots increased with the ensiling time, while that of leaves was the highest at 7 d. The ensiling temperature had no significant effects on the fermentation quality of cassava roots(P>0.05), and all roots silages had a pH near 3.70, while the leaves in silages at 30 and 40 ℃ had more lactic acid and lower pH than those at 20 ℃. The hydrocyanic acid content in cassava roots and leaves gradually reduced with ensiling time, and such reductions mainly took place in the first two weeks. As the ensiling temperature rose, the HCN content of roots and leaves significantly reduced (P<0.05). The detoxification rates of HCN were 55.82% and 63.56% for cassava roots and leaves at 40 ℃, respectively.
As the first batch of medicine, food, and traditional multi-purpose economic plants promulgated by the ministry of health, Perilla frutescens has high nutritional value. The aim of this study was to determine the effects of different treatments on fermentation of P. frutescens straw. The experiments were divided into 5 groups including thecontrol group, group Ⅰ (with 20% corn flour 20 g+1 g·kg-1 Qiangwei 99 starter cultures+0.1 g·kg-1 crude fiber degradation agent+50 mL·kg-1 Trichoderma fermentation solution added), group Ⅱ (with 20% corn flour+1 g·kg-1 Qiangwei 99 starter culture added), group Ⅲ (with 20% corn flour+1 g·kg-1 crude fiber degradation agent added), group Ⅳ (with 20% corn flour+50 mL·kg-1 Trichoderma fermentation solution added). All groups had 3 replicates. The results showed that the sensory score, pH, and contents of organic acids (acetic acid, propionic acid, and butyric) and ammoniac nitrogen in groups Ⅰ and Ⅱ were significantly lower than that of the control group and the other groups (P<0.05). Compared with the control group, the contents of crude fiber (CF) and acid detergent lignin (ADL) decreased significantly and the opposite occurred for crude protein (CP) and crude fat (EE) in the four different treatment groups. Neutral detergent fiber and acid detergent fiber decreased significantly in group Ⅰ and Ⅲ (P<0.05). However, the content of ash between the control group and different treatment groups was not significantly different. The above results showed that adding 20% corn flour 20 g+1 g·kg-1 Qiangwei 99 starter cultures+1 g·g-1 crude fiber degradation agent+50 mL·kg-1 Trichoderma fermentation solution was the best treatment for fermentation of P. frutescens straw.
Calculation of the most appropriate monthly livestock carrying capacity can help with monitoring the seasonal conflict between grass supply and livestock and enable grassland managers to adjust grazing strategies in a timely fashion. As a contribution to effective grassland management, the paper provides a calculation method in which an empirical model based on remote sensing and ground investigation data is combined with monthly dynamic coefficients of grassland yield. This approach was applied to seasonal pasture at Heriheng Village, Henan County, Qinghai Province. The results show that this method can effectively reflect the dynamic changes in proper carrying capacity and identify the appropriate balance between grassland and livestock during the year. In our study region, grassland yield is highest in July and then begins declining gradually. Apart from July, overloading at different levels occurs in all the other months. Based on the current grazing level and the analysis of forage supply, it is proposed that the stocking level in late August should be taken as the most reasonable grazing level. The method of calculating the most suitable monthly livestock carrying capacity, proposed by this paper, can help determine appropriate grazing levels, estimate the ideal balance between grassland and livestock, and provide a theoretical reference for rational utilization and sustainable development of grassland resources.
In this research project, the potato dextrose agar (PDA) plate exposure method was used to collect microorganisms from a sterile room and from a conventional operation room in a microbiology laboratory. The main strains were identified by morphological and molecular morphology. Changes in the bacterial colony after sterile operations, such as spraying with alcohol or wiping the table, were observed. Research showed that the laboratory had a total of 11 kinds of contaminating microorganism, including Bacillus amyloliquefaciens, Dietzia maris, and Arthrobacter globiformis. Altogether, there were eight kinds of bacteria and three kinds of fungi, namely Penicillium sp., Peziza ostracoderma, and Cladosporium cladosporioides. Among them, the dominant strains were Kocuria rosea, A. globiformis, and D. maris, with the colonies numbering 28, 28, and 23, respectively. The study found that the kinds of microorganism of sterile room where placed three ultra clean bench more than conventional operation room, and contains all kinds of conventional operation room. The study indicated that the microbes in the conventional operation room came from the sterile room. There was a large difference between the microorganism species of the laboratory and the common microbial species in the air, indicating that the microbes of the sterile room may have been introduced by improper operations during microbial research. After carrying out sterile operations, the contaminant microorganisms of the inside and the outside of the ultra-clean benches were reduced by 64% and 9%, respectively. The experiments show that wiping out the ultra-clean bench and spraying alcohol can effectively reduce the pollution of microbial cultures. Based on the microbial source, it is necessary to standardize the operation and reduce the air flow between the laboratory and outside. This study provides a scientific basis for the detection, prevention, and control of microbial contamination in a microbiology laboratory.