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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.
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.
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.
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·(m2·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.
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.
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.’
Wild herbaceous flower, owing to its unique ornamental value and strong resistance, has become an important landscaping plant material. In this study, a line transect method was applied to investigate wild herbaceous flower resources in Pingtan. Grey correlation analysis was used to evaluate its development and application values. The aim was to screen excellent landscaping materials for Pingtan. Results showed that: 1) There was a total of 143 species, belonging to 118 genera and 40 families; 2) 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) Species have strong ornamental characteristics. The evaluation scores of flower and leaf color and ornamental value were more than 2; 5) 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 pes-caprae, Limonium sinense, Portulaca pilosa, Viola philippica, Ixeridium chinense and Anagallis arvensis, which could be directly applied in garden configuration.
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-Wiener’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.
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 (7), Mn-CDF (20), and Zn-CDF (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.
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.
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.
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.
To select suitable alfalfa (Medicago sativa) cultivars for planting in the Yumen region. This study selected 15 alfalfa cultivars with relative large planting area and selected Gannong No.3 as control to analyze its productivity and nutritional quality by using the grey correlation method, and then classified these cultivars by using the range method. This study showed that Adrenalin height with second and third age was 98.17 and 90 cm, which significantly higher than control, and Adrenalin with the ratio of dry matter to fresh of the first and third age were 3.13%, which lower than control. Derby and Stockpile T has the highest hay yield compared to control, the hay yield of Derby and Stockpile were 5.83 and 5.82 t·ha–1, repectively. Crude protein content ranged from 7.26%～20.62%, the neutral detergent fiberand the acid detergent fiber ranged from 40.21%～45.64% and 30.43%～35.10%, respectively. WL343HQ, Concept and WL363HQ has the relatively higher dry matter intake, digestible dry matter and relative feeding value, and the value were 2.99%, 65.20%, and 147.32, respectively. These results suggest that Stockpile T and Liangmu No.2 has higher hay yield, and WL343HQ, and WL363HQ has good nutrient quality, indicating that Derby, Golden Empress, WL363HQ and WL343HQ has the greatest performance in the Yumen area.
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: 3 million plant·ha–1, D2: 4.5 million plant·ha–1, D3: 6 million plant·ha–1, D4: 7.5 million plant·ha–1, D5: 9 million plant·ha–1, and D6: 10.5 million plant·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 9 million plant·ha–1, and the best harvest was at the milk-ripening period.
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 bacterial 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 bacterial in the rumen changed with differing ratios of alfalfa and paper mulberry.
The experiment was conducted to investigate the effects of fennel straw replacing corn stover on the rumen fermentation parameters and composition of intramuscular fatty acids in Hu sheep. Forty-eight healthy and disease-free male Hu lambs were selected and divided into control (corn stover), fennel and corn stover, and fennel straw groups. Each group contained 16 sheep, and the experiment included a 14-day transition period, 7-day pre-feeding period, and an 84-day trial period. After the end of the experiment, the rumen fluid was collected to evaluate the rumen fermentation parameters and microorganisms, and the longissimus dorsi muscle was collected to determine intramuscular fatty acid content. The results showed that: 1) when feeding fennel straw to sheep, the ratio of isobutyric acid in rumen significantly decreased (P < 0.05) and the ratio of propionic acid decreased (P > 0.05) compared to that of the control group, while isobutyric acid content was highest in the 50% substitution group; 2) when feeding fennel straw to sheep, the total bacteria content was significantly lower than that of the other groups (P < 0.05), while other rumen microorganisms decreased in the each group (P > 0.05); 3) when feeding the Hu sheep fennel straw and corn stover, a significant increase in iso C16 : 0, iso C18 : 0, C18 : 3 n-3, and CLA intramuscular content (P < 0.05) was observed, while the content of C16 : 0, C18 : 0, C18 : 1 t9\t10\t11, C18 : 2 n-6t, C20 : 1, C22 : 0, and SFA decreased (P > 0.05). In summary, the effect of a 50% replacement of fennel straw for corn stover on the rumen fermentation parameters and muscle fatty acid composition of Hu sheep was deemed to be best.
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%.
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.
Theriaphis trifolii 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 Empress 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 Empress > 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.
In order to enhance the economic value and develop the utilization potential of alfalfa, in this study, protein was extracted from fresh alfalfa using alkali-soluble acid precipitation and was hydrolyzed to prepare angiotensin-converting enzyme (ACE) inhibitory peptides using papain, neutral protease, trypsin, alkaline protease, flavor protease, and pepsin. The results indicated that neutral protease and papain were the appropriate proteases and had higher ACE inhibition rates of 71.48% and 69.99%, respectively, for preparing ACE inhibitory peptides from alfalfa protein. The effects of the combined-enzyme (neutral protease and papain) hydrolysis temperature, time, pH, and ratio on the ACE inhibition rates and hydrolysis degrees of alfalfa protein hydrolysate were investigated. Three variables of pH (X1), temperature (X2), and time (X3) were selected and designed for a response surface test, which used the central combination design principle of Box-Behnken and utilized the ACE inhibition rates as response values to optimize the process conditions of enzymatic hydrolysis of alfalfa protein for preparing ACE inhibitory peptides on the basis of a single factor. The results showed that the optimal conditions for preparing the ACE inhibitory peptides were neutral protease∶ papain = 3∶1, pH = 8.12, temperature = 60 ℃, and time = 6 h, and the ACE inhibition rate was 76.12% when the ACE inhibitory peptides was prepared from alfalfa protein by double-enzymatic hydrolysis. Therefore, we conclude that the alfalfa protein has the potential to be used for preparing ACE inhibitory peptides. These results may be used for further improving the utilization efficiency and economic value of alfalfa.
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.
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.
Developing a professional talent training system, with local and regional characteristics and considering the objectives and position of talent training in Xinjiang Agricultural University, is an important for implementing educational philosophy aimed at talent cultivation, guided by professional theory, guaranteeing the quality of talents, and serving the local economy. In the field of new agricultural sciences, a talent training system with regional characteristics for Pratacultural Sciences in the Xinjiang Agricultural University was constructed through a series of reform measures. These measures included revising the talent training program, optimizing the curriculum, reforming the teaching method, and strengthening practical teaching, according to university’s talent development goal, following the principle of “top-level design, scientific organization, step-by-step implementation, outstanding features, and intensified practice” based on extensive experience in related disciplines at home and abroad, and grasping new developments and new directions in professional development.