Leymus chinensis is a high-quality forage widely distributed in grasslands of Inner Mongolia. It can be classified as either the gray-green type or the yellow-green type according to its leaf color. Previous studies have shown that the gray-green grass has a higher photosynthetic capability and stronger environmental adaptability than the yellow-green type under stressful conditions. However, the mechanism underlying this difference is still unclear. Gray-green and yellow-green grass of the Huhetala grassland in Inner Mongolia were sampled in this study. The concentrations of chlorophyll and carotenoids in the leaves of the two L. chinensis ecotypes were quantitatively determined by a spectrophotometer. The number, size, and morphology of chloroplasts were characterized by transmission electron microscopy. The photosynthetic protein complexes of the gray-green and yellow-green grass were separated via blue native gel electrophoresis (BN-PAGE). The results indicated that the gray-green type had higher concentrations of chlorophyll and carotenoids in its leaves compared with the yellow-green type. Even though there were more chloroplasts per cell in the yellow-green leaves, chloroplasts were larger with a higher number of grana thylakoid in the gray-green leaves. In addition, two kinds of chloroplasts with different morphologies were allocated into different cells in the yellow-green leaves. A higher level of photosystem Ⅱ (PSⅡ) dimers and photosystem Ⅰ (PSⅠ) complexes were detected in the gray-green type through BN-PAGE. It can, therefore, be inferred that the higher concentrations of chlorophyll, carotenoids, and PSⅠ and PSⅡ protein complexes are an important basis for more efficient photosynthesis and stronger environmental adaptability of the gray-green grass ecotype.
Decaploid tall wheatgrass (Thinopyrum ponticum) is a perennial grass with significant tolerance to various biotic and abiotic stresses. To explore the application potential of the common wheat (Triticum aestivum) × Th. ponticum hybrid as a perennial grass, the F1 plants derived from T. aestivum Zhongnong 28 × Th. ponticum were compared with Th. ponticum for biomass accumulation-related traits. The results showed that the F1 hybrid had significantly higher projected area and compactness at the tilling, jointing, heading, and flowering stages, caliper lengths at the tilling, jointing, and heading stages, and object extent X and object extent Y at the tilling and heading stages, but significantly lower mean green color at the tilling and heading stages compared with Th. ponticum. Additionally, the compactness and mean green color in the F1 were significantly higher than in Th. ponticum at 23 d after the first cutting, while the object extent X was lower. The leaf number, leaf length and width, and fresh weight per plant in the F1 hybrid were also significantly higher than those of Th. ponticum at the jointing stage. In both the field as well as the greenhouse, the concentrations of chlorophyll and carotenoids in the F1 hybrid was significantly higher than in Th. ponticum. In addition, the F1 hybrid had higher concentrations of fructose, sucrose, and starch but lower concentrations of glucose in comparison with Th. ponticum around June 1st. Finally, the F1 hybrid produced more herbage yield than Th. Ponticum, regardless of the number of cuttings (once, twice, or thrice a year) in both Beijing and Nanpi. Regarding seed planting, the F1 hybrid yielded more than Th. ponticum by 61.9%–103.5%. Two cuts a year produced the highest herbage yields for both the F1 hybrid and Th. ponticum, of which the first cutting, carried out around June 1st, led to a high yield and good quality. Collectively, the common wheat × tall wheatgrass F1 hybrid has better application potential as a grass than Th. ponticum.
The aim of this study was to evaluate the adaptability and production performance of different sources of Hemarthria in subtropical plains and select the best cultivars (lines) in the Chengdu area. We carried out a comparative experiment of seven varieties (lines) of Hemarthria in the Chengdu plain. The results showed that in terms of hay production, the yields of ‘H248’ were the highest (the three-year average yield was 32.39 t·hm–2), while the lowest was ‘H203’ (the three-year average yield was 25.16 t·hm–2). Regarding the nutritional quality, the gray correlation analysis revealed that ‘Ya’an’ showed the highest nutrient concentration, followed by ‘H248’, ‘H255’, and ‘H202’. Taking together the hay production and the nutritional quality indicators, the performance and quality of H248, ‘Ya’an’, and ‘H255’ were outstanding and suitable for planting in the Chengdu plain.
The purpose of this experiment was to study the effects of different levels of N-Hydroxymethyl Methionine Calcium (N-HMM-Ca) on the performance, milk quality and rumen fermentation of lactating Holstein cows. 30 lactating Holstein dairy cows were blocked according parity, milk yield and lactation stage, and randomly assigned to 5 groups, 6 in each group. 0, 0.15%, 0.30%, 0.75%, and 1.50% N-HMM-Ca were added to the diet on a dry matter basis. The experiment was continued up to 56 d, including 14 d of adaptation period and 42 d of experimental period. The results showed: 1) Dietary supplementation of 0.15% N-HMM-Ca significantly increased milk production (P < 0.05). 2) Compared with the control group, the lactose rate and milk protein rate were significantly increased in the range of 0.15% to 0.75% (P < 0.05). 3) The apparent digestibility of Crude protein, Ether extract, Calcium and Phosphorus was not affected by the level of N-HMM-Ca, but the 0.15% group significantly increased the apparent digestibility of ADF and NDF (P < 0.05). 4) There was no significant relationship between the pH, VFA and MCP content of rumen fluid and the level of N-HMM-Ca (P > 0.05). 5) The 0.15% group increased the relative expression of Fibrobacter succinogenes、Ruminococcus albus、R. flavefaciens (P < 0.01). In summary, the addition of 0.15% N-HMM-Ca to the diet of lactating dairy cow can effectively improve the production performance, milk quality, and feed digestion as well as utilization. Therefore, it is recommended to add the N-HMM-Ca to the diet of lactating dairy cow and a suitable dose is 0.15%.
A theoretical basis was provided to determine the suitable planting density for high yield cultivation of Avena sativa ‘Baiyan No.7’ in the Western Songnen Plain. Baiyan No.7 was chosen as the material to explore the effects of six density levels (D1: 300 × 104 plants·ha–1, D2: 450 × 104 plants·ha–1, D3: 600 × 104 plants·ha–1, D4: 750 × 104 plants·ha–1, D5: 900 × 104 plants·ha–1, and D6: 1 050 × 104 plants·ha–1) on production performance and photosynthetic characteristics. The results showed that with the increase in planting density, the phenological characteristics of Baiyan No.7 were enhanced, and the growth duration was shortened. The plant height and stem diameter of latter stages decreased significantly with the increase in planting density (P < 0.05). The tiller number of each growth stage decreased significantly with the increase in planting density (P < 0.05). The effect of planting density on oat leaf area index (LAI) was significant (P < 0.05), and with increasing density, the LAI of oat increased from the tillering period to the anthesis period. The change from the anthesis period to the milk-ripening period first showed an increasing trend and then decreased. Planting density had a significant effect on photosynthetic potential at each growth stage and total photosynthetic potential (P < 0.05). With increasing density, the photosynthetic potential first increased before the booting period, and then decreased after the booting period, and the total photosynthetic potential first increased and then decreased. During the anthesis period, the photosynthetic performance of flag leaves decreased significantly with increasing density (P < 0.05). The planting density had a significant effect on the fresh yield and hay at each growth stage (P < 0.05). In most sampling periods, the yields of both fresh oat and hay showed a tendency to first increase and then decrease with the increase in planting density, and reached the highest yield in the D5 treatment. In the different growth periods, the yield of fresh oat and hay was the highest at the milk-ripening period. In this study area, the suitable planting density of Avena sativa ‘Baiyan No.7’ was 900 × 104 plants·ha–1, and the best harvest was at the milk-ripening period.
Based on the trade data from 2008 to 2019, this study analyzes the trade volume and international trade pattern of grass seeds using the H-P filtering method and the ARIMA model(Autoregressive Integrated Moving Average model) to predict import and export volumes. The results show that the import of grass seeds in China has been on the rise since 2008, especially since 2014. The seeds of Lolium perenne, Festuca ovina, and Poa pratensis are mainly imported. The United States, Canada, Denmark, and Argentina are the main source countries. Regarding export, only Medicago sativa seeds are exported to neighboring countries such as Japan and South Korea. The volume of export has decreased yearly, and the grass seed trade shows a net import pattern. The prediction results show that the import of grass seeds in China rises at first and then decreases, reaching a peak of 56.33 thousand tons in 2023. It is estimated that the import of grass seeds will be 54.82 thousand tons by 2030. The export volume of grass seeds has recovered after 2018, and it is expected that in 2030 it will be 756.38 tons. In the short-term, the pattern of net import of grass seeds will continue, and the grass seeds market will continue to be one of high dependence on foreign countries. By analyzing the experience of developed countries such as the United States in production and trade, some suggestions are put forward for the development of the grass industry in China.
To elucidate impacts of changes in the land use types on the soil retention capacity of Zhangjiakou City, the spatial and temporal variations of the land use types and the soil retention capacity of Zhangjiakou City in 2005 and 2015 were assessed by using USLE and GIS tools. The result showed that the main land use types of Zhangjiakou were cultivated land, forest land and grassland. Areas of forest land and construction land increased as the other land use types decreased from 2005 to 2015. The fastest increase area of land use types among all the land use types was forest land, which was converted from grass land, and the lowest decrease area of land use types was cultivated land, which was converted into construction land. Meanwhile, a two-way flow between forest land and grassland appeared. An obvious difference in the soil retention capacity in the Zhangjiakou City appeared among different land use types. Grassland owned the most pronounced increase rate of the soil retention, while forest land owned the most pronounced increase amount of the soil retention. Soil retention amounts in the grassland and forest land accounted for 50% of all land use types. Soil retention capacity was increased by 17.52 × 106 t in the Zhangjiakou City in the past 10 years, and this result could be ascribe to increase of land cover. Amount of soil conservation increased in each county in the past 10 years. Yu County owned the highest increase amount of soil conservation, and Qiaoxi District owned the least increase amount of soil conservation among all counties. Furthermore, the soil retention capacity was lower in the northwest regions and higher in the southeast regions of Zhangjiakou City. The highest soil retention capacity appeared in the Chicheng County, and Qiaoxi District owned the lowest soil retention capacity among all counties. Finally, soil retention capacity in the Bashang Regions was obviously higher than that in the Baxia Regions, and soil retention amount accounted for 80% of Zhangjiakou City, and the increase amounts of soil retention in the Bashang Regions was 11.63 × 106 t. The results of this study was helpful to understand the changes of land use and soil retention function after the implementation of ecological engineering in the Zhangjiakou City, and this could provide a scientific basis for promoting ecological protection and developing soil erosion control plan in the future.
The aim of this study was to investigate the effects of different types of starters with various NDF sources on growth performance and gastrointestinal development of Hu lambs. Sixty healthy Hu lambs, each with initial body weight of 3.47 ± 0.69 kg, were selected, and the single-factor experimental design was adopted. The lambs were divided into four treatments and fed different starters with different neutral detergent fiber (NDF) sources, which included alfalfa hay (AH), soybean hull (SH), oat hay (OH), and beet pulp (BP). The results showed that the final body weight, carcass weight, average daily gain, and average daily feed intake were significantly higher in AH-fed lambs than in the other lambs (P < 0.05). The kidney index and gall bladder index of SH-fed lambs were significantly lower than those of lambs feeding on OH and BP (P < 0.05), while the ratio of rumen content weight to whole stomach content and the whole gastrointestinal tract content weight were significantly higher compared with those in OH- and BP-fed lambs (P < 0.05). The ratio of reticulum content weight to whole stomach content, the whole gastrointestinal tract content, and body weight of SH-fed lambs were significantly lower compared with those in other lambs (P < 0.05). The ratio of rumen weight to whole stomach weight and the whole gastrointestinal tract weight of AH- and OH-fed lambs were significantly higher than those of BP-fed lambs (P < 0.05). The ratio of rumen weight to body weight was significantly higher in SH-fed lambs than in AH-fed lambs (P < 0.05). The ratio of rumen volume to whole stomach volume of SH-fed lambs was significantly higher than that of OH-fed lambs (P < 0.05). The ratio of rumen volume to whole gastrointestinal tract volume was significantly higher in AH- and SH-fed lambs than in BP-fed lambs (P < 0.05). The ratio of abomasum weight to whole stomach weight of BP-fed lambs was significantly higher than that of SH-fed lambs (P < 0.05). The ratio of jejunum weight and volume to whole gastrointestinal tract weight and volume of OH-fed lambs was significantly higher than that of SH-fed lambs (P < 0.05). In conclusion, because of the different structure of the fiber in different starters with different NDF sources, apparent differences were observed among different treatments in growth performance and gastrointestinal tract development of Hu lambs.
Qilian Mountain National Park plays an important role in water conservation and ecological balance and is an important ecological security barrier in Hexi and even northwest China. In the present study, the NPP estimation model-CASA model and MODIS NDVI remote sensing product were used to calculate NPP values for the 2000–2018 period, and univariate linear regression, correlation analysis, meteorological data, and human activities data, were used to analyze the temporal and spatial variation characteristics of NPP in the study area and to investigate relationships between terrain, climate, and human activities. 1) During 2000–2018, the NPP of Qilian National Park exhibited an upward trend of fluctuation, with a multi-year average of 167.35 g·m–2·a–1. Meanwhile, monthly changes in NPP exhibited increasing trends, and the growth rate was obviously different. Among them, the growth rate of vegetation NPP from May to September was significantly greater than that of other months. 2) Multi-year mean NPP values decreased from southeast to northwest, and the vegetation NPP exhibited obvious seasonal variation, with NPP being highest during summer, followed by autumn, and lowest during winter. 3) Overall, the NPP of Qilian Mountain National Park first increased and then decreased with increasing elevation and slope, and the vegetation NPP of overcast slopes was greater than that of sunny slopes. Compared with temperature, the correlation between vegetation NPP and precipitation was higher, with a correlation coefficient of 0.632 (P < 0.01). When the intensity of human activity reached > 20%, there was an obvious negative correlation between NPP and human activity intensity. In general, topography and climate factors play a decisive role in the determination of vegetation NPP in the study area. The present study provides a reference for scientific evaluation of the ecological management of Qilian Mountain National Park, as well as for the development of ecological policy and management of the ecological environment, and provides relevant theoretical basis for the further realization of the regional natural-economic-social coordination and sustainable development.
Forage-livestock balance is the basis for the sustainability of animal husbandry and for the health of grassland ecosystems in the Tibet autonomous region. Thus, the present study used two economic income objectives for raising livestock to estimate the forage-livestock balance between two neighboring counties (Namling County, in the YNL River Region, and Shenza County, in the northern Tibetan Plateau) and to propose optimal feasibility plan for achieving forage-livestock balance in the Tibet autonomous region. The results indicated that livestock number will increase if the objective of husbandry is economic gain and will, otherwise, remain stable. Meanwhile, regardless of objective, both counties experienced a shortage in forage supplies from 2015 to 2017. Indeed, Namling and Shenza County experienced forage supply shortages of 140,500–166,500 tons and 73,900–96,700 tons, respectively, when maintaining livestock number and shortages of 293,500–328,900 tons and 226,700–257,000 tons, respectively, when maximizing economic income. The feasibility plan proposed for balancing forage supply and livestock demand involves the establishment of pasture silage maize (Zea mays), oat (Avena sativa), and alfalfa (Medicago sativa). To maximize economic income in Namling County and to maintain livestock number in Shenza County, the counties should reduce sheep number by 69,700–116,000 and 128,000–167,500, respectively, or increase alfalfa production by 53,400–88,800 tons and 73,900–96,700 tons.
To establish a scientific basis for vegetation restoration and reconstruction of alfalfa grasslands on the Loess Plateau, it is necessary to study the effects of different ecosystem functions on habitat reclamation. Accordingly, the aim of the present study analyzed different succession stages of alfalfa land in a semi-arid loess watershed, and the root mean square deviation (RMSD) method was used to analyze species diversity, aboveground carbon storage, soil moisture storage, and trade-offs between the five ecosystem functions of soil organic carbon storage and soil total nitrogen storage. The relativereturns of species diversity, aboveground carbon storage, soil water storage, soil organic carbon storage, and soil total nitrogen storage changed significantly with the community succession (P < 0.05), and the relative yields of aboveground carbon storage, soil organic carbon, and soil total nitrogen increased with succession, whereas species diversity and soil moisture consumption were reduced. All ecosystem functions were centered between soil organic carbon storage and soil total nitrogen storage, and the trade-off between these factors was minimal, which indicated that the factors were synergisticand that the whole recovery stage value was 0.13. Upon restoration to the Leymus secalinus community stage, the trade balance between the five ecological functions was the most balanced, with an average RMSD of only 0.21, and species diversity was highest at the long-shoulder grass community stage. The present study establishes a scientific evaluation system and theoretical guidance for the sustainable restoration of farmland to native habitat.
To investigate the effect of vegetation type on the ecological stoichiometric characteristics of wetlands, soil samples were collected from a reed (Phragmites communis) stand, flower field, grassland, and poplar (Populus euramevicana ‘San Martino’ and P. deltoides ‘Lux’) plantation along Chaohu Lake, and the soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) levels of the samples were measured. The SOC, TN, and TP contents of the flower field were highest, whereas those of the grassland were lowest (flower field > poplar plantation > reed stand > grassland), and the SOC, TN, and TP contents, as well as their stoichiometry were significantly affected by vegetation type (P < 0.05). Furthermore, soil SOC, TN, and TP were significantly correlated (P < 0.01), regardless of vegetation type, and the soil carbon to nitrogen (C/N) ratio was stable, whereas the soil carbon to phosphorus (C/P) and nitrogen to phosphorus (N/P) ratios were affected by vegetation type (poplar plantation > flower field > grassland > reed stand). Therefore, soil P can become the nutrient-limitation indicator in this specific study area. In addition, soil pH was the main environmental determinant of SOC, TN, and TP contents and of the ecological chemometrics of soils around Chaohu Lake.
To study the effect of native arbuscular mycorrhizal fungi (AMF) on the growth and competition of grass species of different sizes, Elymus nutans and Poa crymophila were planted singly, in pairs, or in mixed pairs in an artificial grassland, which simulated non-competition, intraspecies competition, and interspecies competition conditions, respectively, and some of the plantings were inoculated with native AMF. The native AMF successfully colonized the roots of both E. nutans and P. crymophila and significantly improved the biomass, height, and tiller number of both plants. In contrast, the AMF significantly reduced the competitive ability (relative yield, relative yield total, and aggressivity index) of E. nutans, but increased that of P. crymophila. These results demonstrate that, even though AMF can promote the growth of both species in the absence of interspecific competition, it preferentially promotes the growth of P. crymophila under interspecific competition and may differentially contribute to the competitive ability of the two plant species in natural communities. The results also indicate that AMF plays an important role in the regulation of plant interspecific relationships and in the maintenance of community species diversity.
Using wheatgrass DNA as a template, both single-factor and orthogonal-design methods were used to optimize the concentrations of five components (dNTPs, Mg2+, DNA template, primers, and Taq DNA polymerase) that influence marker amplification in simple sequence repeat (SSR)-PCR systems. The optimal SSR-PCR system for wheatgrass included 250 μmol·L–1 dNTP, 2.25 mmol·L–1 Mg2+, 0.60 mmol·L–1 for each primer, 40 ng·μL–1 DNA, and 0.75 U Taq DNA polymerase, with a total reaction volume of 20 μL. This optimization, which could improve the definition and reliability of SSR bands, establishes a foundation for genetic mapping in wheatgrass, as well as for the localization of important QTLs and, thus, molecular marker-assisted breeding.
Nanopriming is the use of nanoparticles to improve seed germination, as well as plant growth and stress tolerance. This paper reviews seed nanopriming methods and their application effects in different plant seeds. In addition,we analyzed the factors that influence the seed priming effect and explained physiological and biochemical mechanisms. The paper also discusses the application of nanopriming and which research directions deserve further exploration.
The present study investigated the effects of net-wind and wind-sand flow on the malondialdehyde content, membrane permeability, protective enzyme activity, and osmoregulation substance content of Lycium ruthenicum leaves with wind speeds of 0 (CK), 6, 9, 12, and 15 m·s–1. The net-wind treatment, malondialdehyde content, superoxide dismutase(SOD)activity, catalase(CAT) activity, soluble protein content, and soluble sugar content decreased, whereas membrane permeability and peroxidase(POD) activity increased, and proline content increased first and then decreased. Under the wind-sand flow treatment, malondialdehyde content, POD activity, and soluble sugar content all increased first and then decreased, whereas the trends of other indicators were identical to those of the net-wind treatment. Both the net-wind and wind-sand flow treatments damaged the leaves, and this stress caused L. ruthenicum to increase POD activity and to enhance osmotic regulation, either by eliciting increases in proline content (net-wind flow stress) or by eliciting increases in both proline and soluble sugar contents (wind-sand flow stress).
Metal tolerant protein (MTP) is an important member of the cation transporter (cation diffusion facilitator, CDF) family and plays an important role in heavy metal transport and detoxification by plants. In the present study, MTP sequences from model plants and BLAST analysis were used to identify a total of 40 MTP genes in the genome of Alternanthera philoxeroides, and a variety of bioinformatics analysis software and online tools were used for the bioinformatics analysis (e.g., phylogenetic reconstruction, conserved domain analyses and gene structure analysis of the identified genes). The results showed that most of those 40 identified ApMTP genes contained two to six transmembrane domains (TMD), and phylogenetic analysis indicated that the genes belonged to the Fe/Zn-CDF (n = 7), Mn-CDF (n = 20), and Zn-CDF (n = 13) sub-families. Furthermore, a conserved motif (HXXXD) was identified on or around the TMD-II and TMD-V of the Zn-CDF and Zn/Fe-CDF subfamily members, and another (DXXXD) was identified on the TMD-II and TMD-V of the Mn-CDFs subfamily members. The expression pattern of each gene was investigated by extracting relevant information from NCBI. The expression pattern analysis showed that ApMTP has the characteristics of tissue specific expression and response to different treatments such as root hypokalemia.
The frequency, duration, and severity of abiotic stress on plant growth have been reported to increase, owing to environmental deterioration, and have caused created losses in both agricultural and animal husbandry production. Thus, the improvement of stress resistance in such forage crops is urgently needed. One Medicago species, Medicago ruthenica, can survive harsh environments, owing to its high stress tolerance, and has the potential to be used both as a breeding resource for improving the resistance of forage crops and as an ecological treatment and high-quality feed. Previous studies of M. ruthenica have mainly focused on the species’ classification, distribution, genetic diversity, biological characteristics, agronomic characteristics, cultivar introduction, and breeding. Accordingly, the aim of the present study was to review studies published with the last 10 years that have investigated the morphological, physiological, and molecular responses of M. ruthenica to abiotic stress. Future research directions and potential applications are also discussed to provide a reference for the future development and use of M. ruthenica, for grassland improvement, and for cultivating new forage varieties. Future research directions should include the development of new forage varieties using the stress resistance genes of M. ruthenica and the investigation of plant hormone responses to stressful conditions.
To identify the important pathways related to the drought-resistant metabolic mechanism of ryegrass, the main metabolites of blue heaven were detected and studied by gas chromatography-mass spectrometry (GC-MS) under natural drought stress. Using partial least squares discrimination analysis and principal components analysis could completely distinguish between the control and drought stress group; furthermore, there were 19 metabolomic markers obtained by the s-plot analysis. Abundance of 10 biomarkers decreased, namely itaconic acid, taurine, sucrose, glucose, lysine, isoleucine, tyrosine, asparagine, myo-inositol, 1-aminocyclopropane-1-carboxylic acid. Abundance of nine biomarkers increased, namely fructose, phenylalanine, homoserine, 1-hydrogen indole, threonine, phosphate, creatinine, citric acid, malic acid. Enriched pathway analysis by MetaboAnalyst 4.0 obtained nine significant metabolic pathways (P < 0.05), namely Ascorbate and aldarate metabolism; Glycine, serine and threonine metabolism; Alanine, aspartate and glutamate metabolism; Citrate cycle (TCA cycle); Galactose metabolism; Aminoacyl-tRNA biosynthesis; Arginine and proline metabolism; Lysine biosynthesis; Cyanoamino acid metabolism. The nine pathways were associated with drought resistance of ryegrass. The main metabolic pathways of Lolium multiflorum under drought stress were identified through the study, which is of great significance to explore the mechanism of drought resistance metabolism of Lolium multiflorum and would provide reference for further promotion of Lolium multiflorum.
Theriaphis trifolii (Monell) is a crucial pest in alfalfa field, which causes serious harm to alfalfa production in most areas in China. In our study, the feeding behavior of aphid were screened at the alfalfa seedling stage. The change of alfalfa biomass under aphid stress were estimated and the population dynamics of aphids was also assessed on different alfalfa cultivars. The results showed that the total duration of C wave and E1 wave on Gannong No.4 was the longest, being 179.52 and 27.24 min, respectively. The total duration of E2 wave was 29.49 min and it was significantly lower than that on the other four cultivars (P < 0.05). The E1 wave of the aphid in the Golden Queen and the Crown was significantly shorter than that on other cultivars (P < 0.05), while the total duration of E2 wave was significantly higher than that on other cultivars (P < 0.05). There was no significant difference in EPG (electronic penetration graph) between Zhongmu No.3 and MF4020 (P > 0.05). EPG technique on the alfalfa susceptibility to spotted alfalfa aphid were coincided with the approch of aphid abundance. The resistance level of alfalfa to aphid was ranked as the following: Gannong No.4 > Zhongmu No.3 > MF4020 > Golden Queen > Crown. The estimation of alfalfa biomass also indicated that Gannong No.4 and Zhongmu No.3 were both resistant cultivars which are suitable for extension in Ningxia practically.
Wild herbaceous flower, because of unique ornamental value and stronger resistance, has become an important plant landscaping material. In this study, the line transect method was applied to investigate wild herbaceous flower resources in Pingtan. The grey correlation analysis was used to evaluate its development and application values. The aim is to screen the excellent landscaping materials for Pingtan. The results showed that: 1) There were 143 species in total, belonging to 118 genera and 40 families; 2) These wild herbaceous flowers were widespread in coastal sandy land, bedrock coast and hillside grassland, where they accounted for 51.05%. They accounted for 41.26% in field roadsides and wasteland; 3) The resistance of species was stronger, saline resistance species accounted for 53.15%, drought and barren resistance species accounted for 34.97%, waterlogging resistance species accounted for 11.88%; 4) These species have strong ornamental characteristics. The evaluation scores of flower colour, leaf colour and ornamental value are more than 2; 5) The comprehensive evaluation results showed that the degree of correlation with ideal species, in 31 of the 143 wild herbaceous flowers, was higher than 0.8, including Ipomoea ps-caprae, Limonium sinense, Portulaca pilosa, Viola philippica, Ixeridium chinense and Anagallis arvensis, which could be directly applied to garden configuration.
To select suitable alfalfa (Medicago sativa) cultivars for planting in the Yumen region, we compared the main local variety, Gangnong No. 3, with 15 varieties introduced over a larger area. Using the grey correlation method and the nutritional quality of the production performance indicators, we completed a comprehensive analysis testing the varieties with poor methods of adaptability for grading. The results showed that the height of Adrenalin at the second and third ages was 98.17 and 90.00 cm, respectively, which were significantly higher than that of the control group (P < 0.05). The lowest fresh-dry ratios of the first-age and third-age cultivars were Barricade and BR4010, respectively, which were both 3.13% and were significantly lower than those of the control. The highest hay yield per crop for three years was for Derby and Stockpile T, which were 5.83 t·hm–2 and 5.82 t·hm–2, respectively. The crude protein contents ranged from 17.26% to 20.62%, and the neutral and acid washing fiber contents ranged from 40.21% to 45.64% and 30.43% to 35.10%, respectively. The highest dry matter intake, digestible dry matter, and relative feeding value varieties were WL343HQ, Concept, and WL363HQ with values of 2.99%, 65.20%, and 147.32, respectively. Through the analysis of the production characters and nutritional quality characters of the tested alfalfa varieties, the results showed that Derby, Stockpile T, and Liangmu No.2 had high yield. WL343HQ, Golden Empress, and WL363HQ had positive nutritional quality; Derby, Golden Empress, WL363HQ and WL343HQ had the greatest performance in the Yumen area.
The body weight and body size of 207 male Hu lambs aged 0～180 days were measured under house feeding conditions, and three models, Logistic, Gompertz, and Von Bertalanffy, were used to fit the growth process of male Hu lambs from 0 to 180 days. We then analyzed and compared the growth parameters and model predicted values to evaluate the growth and development characteristics of Hu sheep. The results showed that the body weight and body size of male Hu lambs increased gradually from birth to 180 days. The male Hu lambs were at the peak of body weight growth from 0 to 160 days, but the development of body size occurred in stages, and the growth range of body size was different in each period. There was a significant positive correlation between body weight and body size (P < 0.01), and the correlation coefficient between body weight and chest circumference was the highest, followed by body length, body height, and circumference of cannon bone. The Logistic, Gompertz, and Von Bertalanffy models could fit the growth trend of Hu sheep from 0 to 180 days old, with R2 ≥ 0.995. By comparing the measured body weight with the predicted body weight estimated by the model, it is found that the Gompertz growth model has a more suitable fitting effect.
Spring wheat (Triticum aestivum) is the main cereal crop in the rainfed agricultural area of the Loess Plateau. Alfalfa (Medicago sativa) is also widely cultivated in this area. Cropping systems are dominated by continuous spring wheat in the north-western Loess Plateau of China, and the inclusion of alfalfa in cereal-based cropping systems is a traditional practice as well. Continuous production of alfalfa can form a dry soil layer and have a serious impact on the growth of subsequent crops. The aim of this study was to discuss the soil moisture characteristics of the 0 – 300-cm soil layer on land with different standing years of alfalfa and the alfalfa-spring wheat rotation system on the western Loess Plateau and to determine the soil moisture response to alfalfa standing years and succession spring wheat over an 8-year (2012–2019) field experiment on a 9-year-old alfalfa pasture. The results showed that the soil water content in the 50 – 110-cm soil layer was 14.17% in 1-year-old alfalfa and began to present light desiccation. The soil moisture in the 110 – 200-cm soil layer was 12.39% after 3-year-old alfalfa and showed light desiccation. Furthermore, the soil moisture in the 200 – 300-cm soil layer was 13.50% in the third year of alfalfa planting, which was lower than that under withering humidity and was severely desiccated. After the 9-year-old alfalfa was removed, the moisture of the desiccated soil layers recharged significantly over the rotation year. The soil moisture in the 50 – 110-cm soil layer fully recharged after five years of rotation, and the soil moisture in the 110 – 200-cm soil layer was fully recovered after six years of rotation. The soil moisture in the 200 – 300-cm soil layer after seven years of spring wheat rotation was only 15.11%, which could not be fully recovered. In conclusion, the soil profile was very dry after long-term continuous alfalfa production, especially the soil layer below 200 cm which was severely desiccated. Therefore, to maintain high land productivity and improve soil water storage conditions, crop rotation is needed after long-term continuous alfalfa production in the semiarid Loess Plateau of China.
The genetic diversity of 29 Bromus inermis accessions was evaluated with 23 agronomic characteristics using principal component and clustering analysis. The results showed that the different accessions exhibited various degrees of diversity for the available 23 traits, in which the largest spikelet variation was the largest 32.92%. The twenty-three characters were transformed to six principal components that represented the main information of the original target, and the cumulative contribution rate was 77.92%. The 29 B. inermis accessions were divided into three groups. Group Ⅰ had tall plants, fewer spikelets, and small leaves. Group Ⅱ had short plants, thin stems, and light seeds. Group Ⅲ had big leaves, multiple spikelets, and heavier seeds. The exotic accessions in this study have a certain practical significance for enriching the germplasm resources of China's bromegrass and for carrying out breeding of several varieties.
To investigate the change law of nutrients in soil-crop ecosystems, ripe Puroindoline located in the loess semi-arid region of Longdong, soil at a depth of 0–40 cm, and four different irrigation treatments [W50 (50 mm), W100 (100 mm), W150 (150 mm), and W200 (200 mm) ], were selected to analyze the nutrient and ecological stoichiometric characteristics of soil and leaves. The results showed that 1) the content of soil organic carbon and total nitrogen first increased and then decreased as the amount of irrigation increased, and the total phosphorus content did not change much with increased irrigation; organic carbon and total nitrogen content in the 0–40 cm soil layer decreased as soil depth increased, and the total phosphorus content did not change significantly as soil depth increased. 2) The content of C, N, and P in Puroindoline first increased and then decreased as amount of irrigation increased. When the irrigation amount was 150 mm, the maximum value was reached; the ratios of leaf C∶N, C∶P, and N∶P first decreased and then increased. According to the N∶P < 14 observed in the Puroindoline leaf, the growth of Puroindoline in Longdong was limited mainly by N. 3) There was a significant correlation between soil and leaf nutrient transformation in Puroindoline, and C∶P was the most sensitive to the nutrient relationship. The results showed that nitrogen fertilizer should be increased to ensure higher and more stable yield of Puroindoline when the irrigation amount is 150 mm.
To elucidate the germination rate of pearl millet (Pennisetum glaucum) germplasm resources, seeds were artificially aged at 45 ℃ and 99% relative humidity for 0, 4, 8, 12, 16, 20 and 24 h. After aging, they were analyzed for genetic integrity. The results showed that the germination rate, percentage of polymorphic bands (PPB), number of alleles (Na), effective number of alleles (Ne), Nei’s gene diversity index (H), and Shannon’s information index (I) of the treated group were lower than 0 h (CK) and had a negative correlation with aging time, which indicated that the genetic integrity of aged seeds decreased compared with CK. Aged seeds were significantly different (P < 0.05) from CK regarding of PPB, Ne, H and I, when the germination rate went down to 68.23%, which indicated that the regeneration germination rate of P. glaucum was 68.23%. In conclusion, the germplasm resources of P. glaucum should be updated when the germination rate decreased to 68.23% and the genomic-SSR markers could be used to evaluate the effects of seed aging on genetic integrity for its high polymorphism, and low germination was a disadvantage for maintaining the genetic integrity of germplasm resources.
To clarify the effect of the addition of nitrogen and silicon fertilizer on the growth and net photosynthetic rate of Thermopsis lanceolate, we set up experiments in an alpine meadow. The treatments were nitrogen fertilizer (60 g·m–2) addition, silicon fertilizer (0, 4, 8, and 12 g·m–2) addition, and mixed addition of nitrogen and silicon fertilizer. The results are as follows: 1) after nitrogen fertilizer, silicon fertilizer, and mixed fertilizer addition, the plant height of T. lanceolate increased to various degrees; 2) after silicon fertilizer was added, with the increase in application, plant biomass, leaf biomass, specific leaf area, and net photosynthetic rate assumed a trend where it first increased and subsequently decreased; 3) after nitrogen fertilizer was added, plant biomass, leaf biomass, specific leaf area, and net photosynthetic rate decreased significantly (P < 0.05); 4) compared with nitrogen fertilizer addition alone, addition of silicon fertilizer along with nitrogen fertilizer (NSi1、NSi2、and NSi3) enhanced the specific leaf area and net photosynthetic rate of the plant; and 5) there was a significant positive correlation between specific leaf area and net photosynthetic rate in the plant. Our studies found that nitrogen fertilizer addition inhibited the growth of T. lanceolate and decreased net photosynthetic rate; however, addition of silicon fertilizer along with nitrogen fertilizer improved both characteristics.
Chinese herbal medicine has been used in the feed industry owing to its natural properties, low toxicity, non-resistance, and special biological functions. With the implementation of feed non-resistance and breeding anti-resistance policy, Chinese herbal medicine as an additive in animal feed is been increasingly used, and there has been an increased interest in elucidating its biological functions. At present, Chinese herbal medicinal additives have shown unique advantages in promoting animal production, performance, and immunity. Research on the mechanism of its action focuses mainly on promoting growth, development of immune organs, and other aspects; however, there are relatively few studies focusing on other aspects. In the present study, a Chinese herbal medicine was reviewed as a feed additive for animal growth performance, production, animal product quality, animal health, and the environment. Moreover, the primary biological function and the related mechanism was outlined to provide reference for technical research, product development, and production as Chinese herbal medicinal feed additives in China.
Global climate warming and precipitation variability is expected to increase both the frequency and the intensity of climate extremes, such as severe drought. As a result, the composition of plant community changed and grassland gradually degenerated. Arbuscular mycorrhizal fungi (AMF) can from symbiotic association with the majority of terrestrial plants, which play an important role in plant resistance to environmental stresses. In order to explore the effects of extreme drought on AMF community structure, the experimental platform for simulating extreme drought, Maodeng pasture in Xilin city in Inner Mongolia, was selected as the research area in this study. Based on Illumina sequencing analysis, we measured the composition of AMF community and its relationship with environmental factors in soil ecosystem during different growing seasons under extreme drought. The results showed that: 1) 144 OTUs belonging to 8 genera and 5 families were identified in all samples, among which Glomus was the dominant genus in all treatments. 2) Compared with other extreme drought treatments, the extreme drought at the late growth season significantly reduced AMF colonization and extraradical hyphal length density (P < 0.05). 3) Extreme drought in different periods of the growing season did not significantly change the species richness of AMF, but Shannon-wiener index of AMF community was significantly increased under extreme drought in the late growing season (P = 0.01). Meanwhile, NMDS and PERMANOVA analysis showed that the community structure of AMF changed significantly (P = 0.022). 4) Soil organic carbon, C/N and pH were the main factors contributing to the difference ofchanged AMF community structure.
Under hydroponic conditions, root growth; hydrogen peroxide (H2O2), indole-3-acetic acid (IAA), and zeatin riboside (ZR) content; and related gene expression were assessed in two tolerant tall fescue (Festuca arundinacea) varieties, ‘Commander’ (Cd-tolerant) and ‘Crossfire Ⅲ’ (Cd-sensitive), under different conditions (CK, 50 μmol·L-1; Cd, 50 μmol·L-1; Cd+1 mmol·L-1 dimethyl thiourea [DMTU]). Our results showed that the growth of primary roots of both varieties was inhibited, and the number of lateral roots significantly increased under Cd stress (P < 0.05). IAA and ZR contents decreased significantly (P < 0.05), and cell mortality rate in the root tip elongation area increased. H2O2 content displayed an upward trend with increasing Cd stress time. Among the varieties, ‘Crossfire Ⅲ’ showed significant changes. After DMTU treatment, H2O2 content and the cell mortality rate in the elongation zone of the root tip decreased, and IAA content increased significantly (P < 0.05). The inhibition of the growth of primary roots was alleviated, and it was more prominent in ‘Crossfire Ⅲ’. The trend of AUX1 gene expression was opposite to that of IAA content, and the trend of ipt gene was consistent to that of ZR content. This showed that DMTU can reduce the accumulation of H2O2 caused by Cd stress in plants, reducing the level of cell death, regulating the balance of H2O2 and hormones, and thus alleviating root growth inhibition induced by Cd stress. In addition, the mitigation effect of DMTU on the tolerant tall fescue varieties differed under Cd stress, and the mitigation effect on ‘Crossfire Ⅲ’ is greater than on ‘Commander.’
Rumen fluid was collected from two ruminally fistulated Angus cows aged 20 to 24 months. Using 16S rRNA sequencing technology, the effects of mixed in vitro fermentation of alfalfa and paper mulberry at different ratios on rumen microbial diversity were studied. According to the mass ratio, the experimental materials were divided into five treatment groups: 0∶1 (DA), 1∶3 (D3A1P), 1∶1 (D1A1P), 3∶1 (D1A3P), and 1∶0 (DPM). Rumen fluid was collected for detection, and bacterial diversity was analyzed after fermentation for 96 hours. Shannon and Simpon α-diversity index was not significantly different across the five groups (P > 0.05). Chao1 indices of D1A3P, D3A1P, and D1A1P were significantly higher than those of DA and DPM (P < 0.05). ACE index of D1A3P was significantly higher than that of the other groups (P < 0.05). Community structure analysis showed that the dominant phyla were Firmicutes, Bacteroidetes, Proteobacteria, Euryarchaeota, and Spirochaetes. The relative abundance of Firmicutes in DA, D1A1P, and DPM was significantly higher than that in the other two groups (P < 0.05). The relative abundance of Proteobacteria in D1A3P was significantly higher than that in the other groups (P < 0.05). The relative abundance of Euryarchaeota in D3A1P was significantly higher than that in the other groups (P < 0.05). At the genus level, the relative abundance of unidentified Bacteroidales in D1A1P was significantly higher than that in the other groups (P < 0.05). The relative abundance of Sutterella and Succiniclasticum in DPM was significantly higher than that in the other groups (P < 0.05). At the phylum and genus levels, the relative abundance of microbes in the rumen changed with differing ratios of alfalfa and paper mulberry.
Increasing atmospheric nitrogen and phosphorus depositions regulate net ecosystem CO2 exchange (NEE) and carbon source/sink function by affecting the balance between photosynthetic and respiratory processes of plant ecosystems, and thus feeding back to global climate change. In this study, we conducted a manipulative nitrogen and phosphorus addition experiment to investigate their potential effects on carbon cycling processes and the carbon source/sink function of meadow steppe in Hulunbuir, Inner Mongolia. We found that nitrogen addition led to higher ecosystem respiration (ER) by the stimulation of autotrophic respiration (AR) and greater ecosystem CO2 emission due to its stronger positive effects on ER than on gross ecosystem photosynthesis (GEP). In addition, adding phosphorus alone showed non-significant effects on GEP, ER, and NEE, but adding it together with nitrogen lowered CO2 emission compared with adding nitrogen alone. Furthermore, all treatments appeared as net CO2 sources potentially caused by seasonal droughts. Our results suggest that precipitation and nitrogen deposition interactively determine NEE of meadow steppe in Hulunbuir, Inner Mongolia and that the drying climate and increasing nitrogen deposition can turn this region into a net CO2 source.
This study assessed the effects of three major soil heavy metal pollutants (Cu, Ni, and Pb) and salinity, drought (100.0 mmol·L–1 NaCl+2.0% PEG) on seed germination characteristics of the halophyte Halogeton glomeratus to better understand the stress tolerance of this species. Compared to the control treatment (100.0 mmol·L–1 NaCl+2.0% PEG), lower Cu2+ concentrations significantly promoted (P < 0.05) the germination of H. glomeratus seeds even under salinity and drought stress, whereas lower Ni2+ and Pb2+ concentrations showed little effect on seed germination. However, higher Cu2+, Ni2+, and Pb2+ concentrations inhibited seed germination. Seedling length, fresh weight, dry weight, and root activity presented different downward trends. Plant tissue ion content remained low under stress induced by low metal concentrations but increased rapidly under stress induced by high metal concentrations. In cluster analysis, the metal concentrations were grouped into two categories as 1.0 mmol·L–1 Cu2+ and Ni2+ and 3.0 mmol·L–1 Pb2+. In addition, principal component analysis revealed that germination percentage and germination energy showed the highest contribution rate under Cu2+ and Ni2+ treatments and dry weight showed the highest contribution rate under Cd2+ treatment. These results indicate that salinity, drought (100.0 mmol·L–1 NaCl+2.0% PEG) and low heavy metal concentrations (1.0 mmol·L–1 Cu2+ or Ni2+ and 3.0 mmol·L–1 Pb2+) had little effect on the germination and seedling growth of H. glomeratus. Germination percentage and germination energy can be used for evaluating the tolerance of H. glomeratus to Cu and Ni and dry weight to evaluate the tolerance of H. glomeratus to Pb during the germination period.
Grass and Epichloë endophyte symbionts are an important direction in the study of plant–microbe and agro–microbe systems. Over the past thirty years, research on wild barley (Hordeum brevisubulatum) endophytic symbionts has revealed outstanding findings. This article summarizes advances in research from two aspects: wild barley H. brevisubulatum and its endophytic symbiont E. bromicola. The distribution of E. bromicola in host tissue and its infection rate, detection and removal methods, biophysiological properties, morphology, and alkaloid production are described. The resistance of the symbiont E. bromicola to abiotic (salinity, drought, water logging, cold, and seed aging) and biotic (pathogens and pests) stresses as well as the effects of exogenous substances on the symbiont are discussed. The article prospects the extraction of literature on wild barley endophytes and the mechanisms for improving resistance (at the gene and protein level) using a novel endophyte to breed new varieties of grasses and cereals. Given the advantage of resistance to various stresses, these new symbionts and host varieties can be used to improve saline soils and restore ecological balance, among others.
The effects of different herbicide mixtures on the alfalfa (Medicago sativa L.) yield and weed control effect were explored by applying different herbicide mixtures. The results showed that the weed control effects of different herbicide combinations was quite good; the dry weight of alfalfa with imazethapyr alone was as high as 1762 kg×hm-2; the dry weight of alfalfa with benazolin-ethyl alone was higher, which was 1897 kg×hm-2; and the dry weight of alfalfa with imazethapyr and bentazone mixture was the highest, 2175 kg×hm-2. Although the weed control effect was poor, the dry weight of alfalfa was 1882 kg×hm-2 when only haloxyfop-P-methyl (CK2) was applied. Except for bentazone, there was no significant difference in the yield of alfalfa among different dose of the same herbicide alone. The herbicide and related mixtures can be used at alfalfa five-trifoliate growth stage in Ar Horqin Banner as follows: imazethapyr 1050 mL×hm-2 + bentazone 1200 mL×hm-2+ haloxyfop-P-methyl 600 mL×hm-2；benazolin-ethyl 300（or 750）mL×hm-2 + haloxyfop-P-methyl 600 mL×hm-2,imazethapyr 1050 mL×hm-2 + haloxyfop-P-methyl 600 mL×hm-2,If the density of broadleaf weeds redroot pigweed (Amaranthus retroflexus L.) is not high enough, also haloxyfop-P-methyl 600 mL×hm-2 can be applied.
In order to clarify the characteristics of the 7 fungi Phialocephala mycorrhizal fungi which isolated from the roots of bilberry in Daxinganling, and were named as JUN-1to JUN-7. The growth characteristics and microstructure were analyzed, and its ability to dissolve phosphorus and the ability to secrete IAA and iron carriers were quantitatively analyzed. The results showed that these 7 mycorrhizal fungi have certain ability to dissolve phosphorus, secrete iron carrier and secrete IAA. Among them, the strongest ability to dissolve phosphorus is JUN-5, followed by JUN-4. The phosphorus solubilizing capacity of these two bacteria is significantly higher than other strains. The phosphorus concentration in the solution is 80-95 mg·L-1 higher than that of CK. The strongest ability to secrete IAA is JUN-7, and the concentration of IAA in the solution is increased by 57.90 mg·L-1 compared with CK. The ability to secrete iron carriers of JUN-4 and JUN- 6 is stronger than other strains . The ratio of the dissolved phosphorus circle to the colony radius can reach 2.5 times or more. The comprehensive analysis indicated that the ability of JUN-4 to dissolve phosphorus and the ability to secrete iron carrier were very strong, and its growth-promoting ability and growth-promoting mechanism could be further analyzed. The results of this study can provide a theoretical basis for the development of rhododendron fungi and the cultivation of blueberry.