African swine fever virus (ASFV) is a lethal pathogen that causes severe threats to the global swine industry and it has already had catastrophic socio-economic effects.  To date, no licensed prophylactic vaccine exists.  Limited knowledge exists about the major immunogens of ASFV and the epitope mapping of the key antigens.  As such, there is a considerable requirement to understand the functional monoclonal antibodies (mAbs) and the epitope mapping may be of utmost importance in our understanding of immune responses and designing improved vaccines, therapeutics, and diagnostics.  In this study, we generated an ASFV antibody phage-display library from ASFV convalescent swine PBMCs, further screened a specific ASFV major capsid protein (p72) single-chain antibody and fused with an IgG Fc fragment (scFv-83-Fc), which is a specific recognition antibody against ASFV Pig/HLJ/2018 strain.  Using the scFv-83-Fc mAb, we selected a conserved epitope peptide (²²¹MTGYKH²²⁶) of p72 retrieved from a phage-displayed random peptide library.  Moreover, flow cytometry and cell uptake experiments demonstrated that the epitope peptide can significantly promote BMDCs maturation in vitro and could be effectively uptaken by DCs, which indicated its potential application in vaccine and diagnostic reagent development.  Overall, this study provided a valuable platform for identifying targets for ASFV vaccine development, as well as to facilitate the optimization design of subunit vaccine and diagnostic reagents

This study investigated the effects of dioscorea opposite waste (DOW) on the growth performance, blood parameters, rumen fermentation and rumen microbiota of weaned lambs.  Sixty healthy weaned Small-Tailed Han lambs (male, (22.68±2.56) kg initially) were used as the experimental animals.  Four levels of concentrate: 0 (control, CON), 10% (DOW1), 15% (DOW2) and 20% (DOW3), were replaced with DOW in the basal diet as experimental treatments.  The results showed that lambs fed the DOW2 diet had a higher (P<0.05) dry matter intake (DMI) than the other groups.  There was no significant difference (P>0.05) among DOW groups in average daily weight gain (ADG), and replacing concentrate with DOW linearly or quadratically increased (P<0.05) the ADG, while lambs fed the DOW2 diet showed greater (P<0.05) ADG than the CON group.  The relative plasma concentration of growth hormone (GH), insulin like growth factor-1 (IGF-1) and insulin were affected by DOW, replacing concentrate with DOW linearly or quadratically (P<0.05) enhanced the plasma concentration of GH, IGF-1 and insulin, which was significantly higher (P<0.05) in the DOW2 group than in the CON, DOW1 and DOW3 groups.  In addition, the DOW treatment showed a lower (P<0.05) concentration of blood urea nitrogen (BUN) than the CON group.  Replacing concentrate with DOW quadratically decreased (P<0.05) the ruminal ammonia nitrogen (NH₃-N) and increased (P<0.05) the total of volatile fatty acids (TVFAs) at 0 and 4 h after feeding as well as linearly decreased (P<0.05) the NH₃-N at 8 h after feeding.  Replacing concentrate with DOW linearly decreased (P<0.05) the propionate and increased the aceate before feeding, and linearly decreased (P<0.05) propionate and quadratically increased (P<0.05) the aceate at 4 and 8 h after feeding.  Lambs fed the DOW2 diet increased the phylum Firmicutes and genera Succiniclasticum and Ruminococcus_1 groups, whereas decreased (P<0.05) the relative abundance of phylum Deferribacteres and genera intestinimonas and Ruminiclostridium.  In summary, replacing the concentrate with 15% DOW was beneficial for improving the rumen fermentation and ADG by increasing the DMI and modulating the rumen microbial community.

Early bacterial colonization and succession within the gastrointestinal tract have been suggested to be crucial in the development of host immunity.  In this study, we have investigated the changes in live weight and concentrations of selected serum parameters in relation to their fecal bacterial communities as determined by high throughput sequencing of the 16S rRNA gene over the same period in lambs.  The results showed that lambs’ growth performance, the serum parameters, fecal bacterial community and fecal bacterial functions were all affected (P<0.05) by age of the lambs.  Similarity within age groups of fecal microbiota was lower in the preweaning period and increased sharply (P<0.05) after weaning at 60 days.  The similarity between the samples collected from birth to 90 days of age and those collected at 120 days of age, increased (P<0.05) sharply after 30 days of age.  Some age-associated changes in microbial genera were correlated with the changes in concentrations of immune indicators, including negative (P<0.05) correlations between the relative abundance of Lachnospiraceae UCG-010, Eubacterium coprostanoligenes group, Ruminococcaceae UCG-005, Ruminococcaceae UCG-009, Ruminococcaceae UCG-013, Ruminiclostridium 6, Ruminococcaceae UCG-008, and Oscillibacter with serum concentrations of lipopolysaccharide (LPS), D-lactate dehydrogenase (DLA), immunoglobulin (IgA, IgM, and IgG), and cytokines (interleukin-1β (IL-1β), IL-6, IL-12, and IL-17), tumor necrosis factor-α (TNF-α), and the relative abundance of these genera increased from 45 days of age.  In conclusion, these results suggested that the age-related abundances of particular genera were correlated with serum markers of immunity in lambs, and there might be a critical window in the period from birth to 45 days of age which provide an opportunity for potential manipulation of the fecal microbial ecosystems to enhance immune function.

Phosphorus (P) is a nonrenewable resource and a critical element for plant growth that plays an important role in improving crop yield.  Excessive P fertilizer application is widespread in agricultural production, which not only wastes phosphate resources but also causes P accumulation and groundwater pollution.  Here, we hypothesized that the apparent P balance of a crop system could be used as an indicator for identifying the critical P input in order to obtain a high yield with high phosphorus use efficiency (PUE).  A 12-year field experiment with P fertilization rates of 0, 45, 90, 135, 180, and 225 kg P₂O₅ ha^–1 was conducted to determine the crop yield, PUE, and soil Olsen-P value response to P balance, and to optimize the P input.  Annual yield stagnation occurred when the P fertilizer application exceeded a certain level, and high yield and PUE levels were achieved with annual P fertilizer application rates of 90–135 kg P₂O₅ ha^–1.  A critical P balance range of 2.15–4.45 kg P ha^–1 was recommended to achieve optimum yield with minimal environmental risk.  The critical P input range estimated from the P balance was 95.7–101 kg P₂O₅ ha^–1, which improved relative yield (>90%) and PUE (90.0–94.9%).  In addition, the P input–output balance helps in assessing future changes in Olsen-P values, which increased by 4.07 mg kg^–1 of P for every 100 kg of P surplus.  Overall, the P balance can be used as a critical indicator for P management in agriculture, providing a robust reference for limiting P excess and developing a more productive, efficient and environmentally friendly P fertilizer management strategy.

Germination and processing are always accompanied by significant changes in the metabolic compositions of rice.  In this study, polished rice (rice), brown rice, wet germinated brown rice (WGBR), high temperature and pressure-treated WGBR (WGBR-HTP), and low temperature-treated WGBR (WGBR-T18) were enrolled.  An untargeted metabolomics assay isolated 6 122 positive ions and 4 224 negative ions (multiple difference ≥1.2 or ≤0.8333, P<0.05, and VIP≥1) by liquid chromatography-mass spectrum.  These identified ions were mainly classified into three categories, including the compounds with biological roles, lipids, and phytochemical compounds.  In addition to WGBR-T18 vs. WGBR, massive differential positive and negative ions were revealed between rice of different forms.  Flavonoids, fatty acids, carboxylic acids, and organoxygen compounds were the dominant differential metabolites.  Based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, there 7 metabolic pathways (phenylalanine/tyrosine/tryptophan biosynthesis, histidine metabolism, betalain biosynthesis, C5-branched dibasic acid metabolism, purine metabolism, zeatin biosynthesis, and carbon metabolism) were determined between brown rice and rice.  Germination changed the metabolic pathways of porphyrin and chlorophyll, pyrimidine, and purine metabolisms in brown rice.  In addition, phosphonate and phosphinate metabolism, and arachidonic acid metabolism were differential metabolic pathways between WGBR-HTP and WGBR-T18.  To sum up, there were obvious variations in metabolic compositions of rice, brown rice, WGBR, and WGBR-HTP.  The changes of specific metabolites, such as flavonoids contributed to the anti-oxidant, anti-inflammatory, anti-cancer, and immunomodulatory effects of GBR.  HTP may further improve the nutrition and storage of GBR through influencing specific metabolites, such as flavonoids and fatty acids.

Phosphorus (P) leaching is a major problem in greenhouse vegetable production with excessive P fertilizer application.  Substitution of inorganic P fertilizer with organic fertilizer is considered a potential strategy to reduce leaching, but the effect of organic material addition on soil P transformation and leaching loss remains unclear.  The X-ray absorption near-edge structure (XANES) spectroscopy technique can determine P speciation at the molecular level.  Here, we integrated XANES and chemical methods to explore P speciation and transformation in a 10-year field experiment with four treatments: 100% chemical fertilizer (4CN), 50% chemical N and 50% manure N (2CN+2MN), 50% chemical N and 50% straw N (2CN+2SN), and 50% chemical N and 25% manure N plus 25% straw N (2CN+2MSN).  Compared with the 4CN treatment, the organic substitution treatments increased the content of labile P by 13.7–54.2% in the 0–40 cm soil layers, with newberyite and brushite being the main constituents of the labile P.  Organic substitution treatments decreased the stable P content; hydroxyapatite was the main species and showed an increasing trend with increasing soil depth.  Straw addition (2CN+2SN and 2CN+2MSN) resulted in a higher moderately labile P content and a lower labile P content in the subsoil (60–100 cm).  Moreover, straw addition significantly reduced the concentrations and amounts of total P, dissolved inorganic P (DIP), and particulate P in leachate.  DIP was the main form transferred by leaching and co-migrated with dissolved organic carbon.  Partial least squares path modeling revealed that straw addition decreased P leaching by decreasing labile P and increasing moderately labile P in the subsoil.  Overall, straw addition is beneficial for developing sustainable P management strategies due to increasing labile P in the upper soil layer for the utilization of plants, and decreasing P migration and leaching.

This study investigated the effects of grape seed extract (GSE) on fresh and cooked meat color and premature browning (PMB) in ground meat patties (85% beef and 15% pork back fat) packaged under high-oxygen modified atmospheres (HiOx-MAP).  The GSE was added to patties at concentrations of 0, 0.10, 0.25, 0.50 and 0.75 g kg^–1.  This study evaluated the surface color, pH, lipid oxidation, and total viable counts (TVC) of raw patties, and the internal color and pH of patties cooked to a temperature of 66 or 71°C over 10-day storage at 4°C.  Compared with the control (0 g kg^–1 GSE), GSE improved the color stability (P<0.05) and significantly inhibited the lipid and myoglobin oxidation of raw patties from day 5 to 10, but GSE had no effect (P>0.05) on TVC.  Patties containing 0.50 and 0.75 g kg^–1 GSE cooked to 66°C exhibited greater (P<0.05) interior redness than the control and reduced the PMB of cooked patties in the late storage stage.  These results suggested that 0.50 and 0.75 g kg^–1 GSE can improve fresh meat color and minimize PMB of HiOx-MAP patties.

Germplasm resources are an important basis for genetic breeding and analysis of complex traits, and research on genetic diversity is conducive to the exploration and creation of new types of germplasm.  In this study, the distribution frequency, coefficient of variation, Shannon–Wiener index, and variance and cluster analyses were used to analyze the diversity and trait differences of 39 fruit phenotypic traits from 570 pear accessions, which included 456 pear accessions from 11 species and 114 interspecific hybrid cultivars that had been stored in the National Germplasm Repository of Apple and Pear (Xingcheng, China).  The comprehensive evaluation indices were screened by correlation, principal component and regression analyses.  A total of 132 variant types were detected in 28 categorical traits of pear germplasm fruit, which indicate a rich diversity.  The diversity indices in decreasing order were: fruit shape (1.949), attitude of calyx (1.908), flesh texture type (1.700), persistency of calyx (1.681), russet location (1.658), relief of area around eye basin (1.644), flavor (1.610) and ground color (1.592).  The coefficient of variation of titratable acidity in the 11 numerical traits of pear germplasm fruit was as high as 128.43%, which could more effectively reflect the differences between pear accessions.  The phenotypic differentiation coefficient V_st (66.4%) among the five cultivated pear species, including Pyrus bretschneideri (White Pear), P. pyrifolia (Sand Pear), P. ussuriensis (Ussurian Pear), P. sinkiangensis (Xinjiang Pear), and P. communis (European Pear), was higher than the within population phenotypic differentiation coefficient V_st (33.6%).  The variation among populations was the main source of variation in pear fruit traits.  A hierarchical cluster analysis divided the 389 accessions of six cultivated pear species, including P. pashia (Himalayan Pear), into six categories.  There were certain characteristics within the populations, and the differences between populations were not completely clustered by region.  For example, Sand Pear cultivars from Japan and the Korean Peninsula clustered together with those from China.  Most of the White Pear cultivars clustered with the Sand Pear, and a few clustered with the Ussurian Pear cultivars.  The Ussurian Pear and European Pear cultivars clustered separately.  The Xinjiang Pear and Himalayan Pear did not cluster together, and neither did the cultivars.  Seventeen traits, three describing fruit weight and edible rate (fruit diameter, fruit length and fruit core size), five describing outer quality and morphological characteristics (over color, amount of russeting, dot obviousness, fruit shape, and stalk length), and nine describing inner quality (flesh color, juiciness of flesh, aroma, flavor, flesh texture, flesh texture type, soluble solid contents, titratable acidity, and eating quality) were selected from the 39 traits by principal component and stepwise regression analyses.  These 17 traits could reflect 99.3% of the total variation and can be used as a comprehensive evaluation index for pear germplasm resources.

Partial substitution of chemical fertilizers by organic amendments is adopted widely for promoting the availability of soil phosphorus (P) in agricultural production.  However, few studies have comprehensively evaluated the effects of long-term organic substitution on soil P availability and microbial activity in greenhouse vegetable fields.  A 10-year (2009–2019) field experiment was carried out to investigate the impacts of organic fertilizer substitution on soil P pools, phosphatase activities and the microbial community, and identify factors that regulate these soil P transformation characteristics.  Four treatments included 100% chemical N fertilizer (4CN), 50% substitution of chemical N by manure (2CN+2MN), straw (2CN+2SN), and combined manure with straw (2CN+1MN+1SN).  Compared with the 4CN treatment, organic substitution treatments increased celery and tomato yields by 6.9−13.8% and 8.6−18.1%, respectively, with the highest yields being in the 2CN+1MN+1SN treatment.  After 10 years of fertilization, organic substitution treatments reduced total P and inorganic P accumulation, increased the concentrations of available P, organic P, and microbial biomass P, and promoted phosphatase activities (alkaline and acid phosphomonoesterase, phosphodiesterase, and phytase) and microbial growth in comparison with the 4CN treatment.  Further, organic substitution treatments significantly increased soil C/P, and the partial least squares path model (PLS-PM) revealed that the soil C/P ratio directly and significantly affected phosphatase activities and the microbial biomass and positively influenced soil P pools and vegetable yield.  Partial least squares (PLS) regression demonstrated that arbuscular mycorrhizal fungi positively affected phosphatase activities.  Our results suggest that organic fertilizer substitution can promote soil P transformation and availability.  Combining manure with straw was more effective than applying these materials separately for developing sustainable P management practices. 

Temperature, as a critical abiotic factor, might influence the effectiveness of biological control by parasitoids in host-parasitoid systems. In this study, Neochrysocharis formosa (Westwood), a larval endoparasitoid, is used to investigate the efficacy of biological control on a vegetable agriculture pest, Liriomyza sativae Blanchard, reared on kidney bean (Phaseolus vulgaris L.), at four constant temperatures (26, 29, 32, and 35°C) under laboratory conditions. Our results show that high temperatures (29, 32, and 35°C) do not significantly affect lifetime host-killing events of female adults by increased daily host-killing events compared to temperature 26°C, although their lifespans decrease with an increase in temperatures. Each life-history trait of female adults (lifespan, parasitism, stinging, or nonreproductive host-killing events) present a linear relation with temperatures and host-feeding events, respectively. Our findings contribute to a better understanding of biocontrol efficacy of parasitoid N. formosa against agromyzid leafminers at high-temperature seasons or environments.

We aimed to develop a set of single nucleotide polymorphism (SNP) markers that can be used to distinguish the main cultivated grape (Vitis L.) cultivars in China and provide technical support for domestic grape cultivar protection, cultivar registration, and market rights protection.  A total of 517 high-quality loci were screened from 4 241 729 SNPs obtained by sequencing 304 grape accessions using specific locus amplified fragment sequencing, of which 442 were successfully designed as Kompetitive Allele Specific PCR (KASP) markers.  A set of 27 markers that completely distinguishes 304 sequenced grape accessions was determined by using the program, and 26 effective markers were screened based on 23 representative grape cultivars.  Finally, a total of 46 out of 48 KASP markers, including 22 markers selected by the research group in the early stage, were re-screened based on 348 grape accessions.  Population structure, principal component, and cluster analyses all showed that the 348 grape accessions were best divided into two populations.  In addition, cluster analysis subdivided them into six subpopulations.  According to genetic distance, V. labrusca, V. davidii, V. heyneana, and V. amurensis were far from V. vinifera, while V. vinifera×V. labrusca and V. amurensis×V. vinifera were somewhere in between these two groups.  Furthermore, a core set of 25 KASP markers could distinguish 95.69% of the 348 grape accessions, and the other 21 markers were used as extended markers.  Therefore, SNP molecular markers based on KASP typing technology provide a new way for mapping DNA fingerprints in grape cultivars.  With high efficiency and accuracy and low cost, this technology is more competitive than other current identification methods.  It also has excellent application prospects in the grape distinctness, uniformity, and stability (DUS) test, as well as in promoting market rights protection in the near future.

Although fungal communities in the gastrointestinal tract have a significant role in animal health and performance, their dynamics within the tract are not well known.  Thus, this study investigated fungal community dynamics in the rumen and rectum of lambs from birth to 4 mon of age by using IT1S rDNA sequencing technology together with the RandomForest approach to determine age-related changes in the fungal ecology.  The results indicated that gastrointestinal fungal community composition, diversity, and abundance altered (P<0.05) with the increasing age of the lambs.  Two phyla, Ascomycota and Basidiomycota, dominated the samples.  Similarity within age groups of the rumen fungi increased sharply after 45 days of age, while the similarity increased (P<0.05) significantly after 60 days of age in the rectum.  The age-related genera, Acremonium, Microascus, Valsonectria, Myrmecridium, Scopulariopsis, Myrothecium, Saccharomyces, and Stephanonectria, were presented in both ruminal and rectal communities, and their changes in relative abundance were consistent at both sites.  The principal coordinates analysis showed significant differences (P<0.05) between the fungal communities in the rumen and rectum.  Our findings demonstrate that both the age of lambs and the gastrointestinal tract region can affect the composition of these fungal communities, and this provides new insight and directions for future studies in this research area.

H7 avian influenza viruses (AIVs) normally circulated among birds before.  From 1996 to 2012, human infections with H7 AIVs (H7N2, H7N3, and H7N7) were reported in Canada, Italy, Mexico, the Netherlands, the United Kingdom and the USA.  Until March 2013, human infections with H7N9 AIVs were reported in China.  Since then, H7N9 AIVs have continued to circulate in both humans and birds.  Therefore, the detection of antibodies against the H7 subtype of AIVs has become an important topic.  In this study, a competitive enzyme-linked immunosorbent assay (cELISA) method for the detection of antibody against H7 AIVs was established.  The optimal concentration of antigen coating was 5 μg mL^–1, serum dilution was 1/10, and enzyme-labeled antibody was 1/3 000.  To determine the cut-off value of cELISA, percent inhibition (PI) was determined by using receiver operating characteristic (ROC) curve analysis in 178 AIVs negative samples and 368 AIVs positive serum samples (n=546).  When PI was set at 40%, the specificity and sensitivity of cELISA were 99.4 and 98.9%, respectively.  This method could detect the antibodies against H7Nx (N1–N4, N7–N9) AIVs, and showed no reaction with AIVs of H1–H6 and H8–H15 subtypes or common avian viruses such as Newcastle disease virus (NDV), Infectious bronchitis virus (IBV) and Infectious bursal disease virus (IBDV), exhibiting good specificity.  This method showed a coincidence rate of 98.56% with hemagglutinin inhibition (HI) test.  And the repeatability experiment revealed that the coefficients of variation (CV) of intra- and inter-batch repetition were all less than 12%.  The data indicated that the cELISA antibody-detection method established in this study provided a simple and accurate technical support for the detection of a large number of antibody samples of H7-AIV.

Available irrigation resources are becoming increasingly scarce in the North China Plain (NCP), and nitrogen-use efficiency of crop production is also relatively low. Thus, it is imperative to improve the water-use efficiency (WUE) and nitrogen fertilizer productivity on the NCP. Here, we conducted a two-year field experiment to explore the effects of different irrigation amounts (S60, 60 mm; S90, 90 mm; S120, 120 mm; S150, 150 mm) and nitrogen application rates (150, 195 and 240 kg ha^–1; denoted as N1, N2 and N3, respectively) under micro-sprinkling with water and nitrogen combined on the grain yield (GY), yield components, leaf area index (LAI), flag leaf chlorophyll content, dry matter accumulation (DM), WUE, and nitrogen partial factor productivity (NPFP). The results indicated that the GY and NPFP increased significantly with increasing irrigation amount, but there was no significant difference between S120 and S150; WUE significantly increased first but then decreased with increasing irrigation and S120 achieved the highest WUE. The increase in nitrogen was beneficial to improving the GY and WUE in S60 and S90, while the excessive nitrogen application (N3) significantly reduced the GY and WUE in S120 and S150 compared with those in the N2 treatment. The NPFP significantly decreased with increasing nitrogen rate under the same irrigation treatments. The synchronous increase in spike number (SN) and 1 000-grain weight (TWG) was the main reason for the large increase in GY by micro-sprinkling with increasing irrigation, and the differences in SN and TGW between S120 and S150 were small. Under S60 and S90, the TGW increased with increasing nitrogen application, which enhanced the GY, while N2 achieved the highest TWG in S120 and S150. At the filling stage, the LAI increased with increasing irrigation, and greater amounts of irrigation significantly increased the chlorophyll content in the flag leaf, which was instrumental in increasing DM after anthesis and increasing the TGW. Micro-sprinkling with increased amounts of irrigation or excessive nitrogen application decreased the WUE mainly due to the increase in total water consumption (ET) and the small increase or decrease in GY. Moreover, the increase in irrigation increased the total nitrogen accumulation or contents (TNC) of plants at maturity and reduced the residual nitrate-nitrogen in the soil (SNC), which was conducive to the increase in NPFP, but there was no significant difference in TNC between S120 and S150. Under the same irrigation treatments, an increase in nitrogen application significantly increased the residual SNC and decreased the NPFP. Overall, micro-sprinkling with 120 mm of irrigation and a total nitrogen application of 195 kg ha–1 can lead to increases in GY, WUE and NPFP on the NCP.

In past 30 years, the wheat yield per unit area of China has increased by 79%. The super-high-yield (SH) cultivation played an important role in improving the wheat photosynthesis and yield. In order to find the ecophysiological mechanism underneath the high photosynthesis of SH cultivation, in situ diurnal changes in the photosynthetic gas exchange and chlorophyll (Chl) a fluorescence of field-grown wheat plants during the grain-filling stage and environmental factors were investigated. During the late grain-filling stage at 24 days after anthesis (DAA), the diurnal changes in net CO₂ assimilation rate were higher under SH treatment than under high-yield (H) treatment. From 8 to 24 DAA, the actual quantum yield of photosystem II (PSII) electron transport in the light-adapted state (ΦPSII) in the flag leaves at noon under SH treatment were significantly higher than those under H treatment. The leaf temperature, soil temperature and soil moisture were better suited for higher rates of leaf photosynthesis under SH treatment than those under H treatment at noon. Such diurnal changes in environmental factors in wheat fields could be one of the mechanisms for the higher biomass and yield under SH cultivation than those under H cultivation. ΦPSII and CO₂ exchange rate in wheat flag leaves under SH and H treatments had a linear correlation which could provide new insight to evaluate the wheat photosynthesis performance under different conditions.

Silicon can improve drought tolerance of plants, but the mechanism still remains unclear.  Previous studies have mainly concentrated on silicon-accumulating plants, whereas less work has been conducted in silicon-excluding plants, such as tomato (Solanum lycopersicum L.).  In this study, we investigated the effects of exogenous silicon (2.5 mmol L^–1) on the chlorophyll fluorescence and expression of photosynthesis-related genes in tomato seedlings (Zhongza 9) under water stress induced by 10% (w/v) polyethylene glycol (PEG-6000).  The results showed that under water stress, the growth of shoot and root was inhibited, and the chlorophyll and carotenoid concentrations were decreased, while silicon addition improved the plant growth and increased the concentrations of chlorophyll and carotenoid.  Under water sterss, chlorophyll fluorescence parameters such as PSII maximum photochemical efficiency (F_v/F_m), effective quantum efficiency, actual photochemical quantum efficiency (Ф_PSII), photosynthetic electron transport rate (ETR), and photochemical quenching coefficient (q_P) were decreased; while these changes were reversed in the presence of added silicon.  The expressions of some photosynthesis-related genes including PetE, PetF, PsbP, PsbQ, PsbW, and Psb28 were down-regulated under water stress, and exogenous Si could partially up-regulate their expressions.  These results suggest that silicon plays a role in the alleviation of water stress by modulating some photosynthesis-related genes and regulating the photochemical process, and thus promoting photosynthesis.

This study investigated the pH/temperature decline of beef carcasses in a typical Chinese abattoir and color development as pH declined during rigor onset.  A natural cubic spline model was used to model the pH/temperature decline for those carcasses which passed through pH 6.0.  Six of the 97 carcasses that exhibited a high (≥6.10) ultimate pH (pHu) (dark-cutting) in the M. longissimus lumborum (LL) were sampled, along with the same numbers of normal pHu and intermediate pHu carcasses (5.40–5.79; 5.80–6.10, respectively), to examine color development within 24 h postmortem.  It was shown that 66.7% of the modeled carcasses were outside the ideal pH/temperature window with a temperature@pH6.0 lower than ideal, suggesting the need for acceleration of the pH decline.  The stable and low a*, b* and chroma values of high pHu beef within the first 12 h indicated dark-cutting beef might be detected earlier than expected.   

To improve efficiency in the use of water resources in water-limited environments such as the North China Plain (NCP), where winter wheat is a major and groundwater-consuming crop, the application of water-saving irrigation strategies must be considered as a method for the sustainable development of water resources.  The initial objective of this study was to evaluate and validate the ability of the CERES-Wheat model simulation to predict the winter wheat grain yield, biomass yield and water use efficiency (WUE) responses to different irrigation management methods in the NCP.  The results from evaluation and validation analyses were compared to observed data from 8 field experiments, and the results indicated that the model can accurately predict these parameters.  The modified CERES-Wheat model was then used to simulate the development and growth of winter wheat under different irrigation treatments ranging from rainfed to four irrigation applications (full irrigation) using historical weather data from crop seasons over 33 years (1981–2014).  The data were classified into three types according to seasonal precipitation: <100 mm, 100–140 mm, and >140 mm.  Our results showed that the grain and biomass yield, harvest index (HI) and WUE responses to irrigation management were influenced by precipitation among years, whereby yield increased with higher precipitation.  Scenario simulation analysis also showed that two irrigation applications of 75 mm each at the jointing stage and anthesis stage (T3) resulted in the highest grain yield and WUE among the irrigation treatments.  Meanwhile, productivity in this treatment remained stable through different precipitation levels among years.  One irrigation at the jointing stage (T1) improved grain yield compared to the rainfed treatment and resulted in yield values near those of T3, especially when precipitation was higher.  These results indicate that T3 is the most suitable irrigation strategy under variable precipitation regimes for stable yield of winter wheat with maximum water savings in the NCP.  The application of one irrigation at the jointing stage may also serve as an alternative irrigation strategy for further reducing irrigation for sustainable water resources management in this area.

High nitrate (NO₃⁻) in vegetables, especially in leaf vegetables poses threaten to human health.  Selenium (Se) is an important element for maintaining human health, and exogenous Se application during vegetable and crop production is an effective way to prevent Se deficiency in human bodies.  Exogenous Se shows positive function on plant growth and nutrition uptake under abiotic and/or biotic stresses.  However, the influence of exogenous Se on NO₃⁻ accumulation in hydroponic vegetables is still not clear.  In the present study, hydroponic lettuce plants were subjected to six different concentrations (0, 0.1, 0.5, 5, 10 and 50 µmol L^–1) of Se as Na₂SeO₃.  The effects of Se on NO₃⁻ content, plant growth, and photosynthetic capacity of lettuce (Lactuca sativa L.) were investigated.  The results showed that exogenous Se positively decreased NO₃⁻ content and this effect was concentration-dependent.  The lowest NO₃⁻ content was obtained under 0.5 µmol L^–1 Se treatment.  The application of Se enhanced photosynthetic capacity by increasing the photosynthesis rate (P_n), stomatal conductance (Cs) and the transpiration efficiency (T_r) of lettuce.  The transportation and assimilation of NO₃⁻ and activities of nitrogen metabolism enzymes in lettuce were also analysed.  The NO₃⁻ efflux in the lettuce roots was markedly increased, but the efflux of NO₃⁻ from the root to the shoot was decreased after treated with exogenous Se.  Moreover, Se application stimulated NO₃⁻ assimilation by enhancing nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS) and glutamate synthase enzyme (GOGAT) activities.  These results provide direct evidence that exogenous Se shows positive function on decreasing NO₃⁻ accumulation via regulating the transport and enhancing activities of nitrogen metabolism enzyme in lettuce.  We suggested that 0.5 µmol L^–1 Se can be used to reduce NO₃⁻ content and increase hydroponic lettuce yield.