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    Crop Genetics · Breeding · Germplasm Resources
    Identification and validation of root-specific promoters in rice
    HUANG Li-yu, ZHANG Fan, QIN Qiao, WANG Wen-sheng, ZHANG Ting, FU Bin-ying
    2015, 14(1): 1-10.  DOI: 10.1016/S2095-3119(14)60763-2
    Abstract ( )   PDF in ScienceDirect  
    Novel promoters that confer root-specific expression would be useful for engineering resistance against problems of nutrient and water absorption by roots. In this study, the reverse transcriptase polymerase chain reaction was used to identify seven genes with root-specific expression in rice. The isolation and characterization of upstream promoter regions of five selected genes rice root-specific promoter (rRSP) 1 to 5 (rRSP1-rRSP5) and A2P (the promoter of OsAct2) revealed that rRSP1, rRSP3, and rRSP5 are particularly important with respect to root-specific activities. Furthermore, rRSP1, rRSP3, and rRSP5 were observed to make different contributions to root activities in various species. These three promoters could be used for root-specific enhancement of target gene(s).
    Effects of inter-culture, arabinogalactan proteins, and hydrogen peroxide on the plant regeneration of wheat immature embryos
    ZHANG Wei, WANG Xin-min, FAN Rong, YIN Gui-xiang, WANG Ke, DU Li-pu, XIAO Le-le, YE Xing-guo
    2015, 14(1): 11-19.  DOI: 10.1016/S2095-3119(14)60764-4
    Abstract ( )   PDF in ScienceDirect  
    The regeneration rate of wheat immature embryo varies among genotypes, howbeit many elite agriculture wheat varieties have low regeneration rates. Optimization of tissue culture conditions and attempts of adding signal molecules are effective ways to increase plant regeneration rate. Inter-culture is one of ways that have not been investigated in plant tissue culture. Moreover, the use of arabinogalactan proteins (AGPs) and hydrogen peroxide (H2O2) have been reported to increase regeneration rate in a few plant species other than wheat. The current research pioneeringly uses inter-culture of immature embryos of different wheat genotypes, and also investigates impacts of AGP and H2O2 on the induction of embryogenic calli and plant regeneration. As a result, high-frequency regeneration wheat cultivars Kenong 199 (KN199) and Xinchun 9 (XC9), together with low-frequency regeneration wheat line Chinese Spring (CS), presented striking increase in the induction of embryogenic calli and plant regeneration rate of CS through inter-culture strategy, up to 52.19 and 67.98%, respectively. Adding 50 to 200 mg L–1 AGP or 0.005 to 0.01 ‰ H2O2 to the callus induction medium, enhanced growth of embryogenic calli and plant regeneration rate in quite a few wheat genotypes. At 50 mg L–1 AGP application level in callus induction medium plant regeneration rates of 8.49, 409.06 and 283.16% were achieved for Jimai 22 (JM22), Jingdong 18 (JD18) and Yangmai 18 (YM18), respectively; whereas at 100 mg L–1 AGP level, CS (105.44%), Chuannong 16 (CN16) (80.60%) and Ningchun 4 (NC4) (62.87%) acted the best. Moreover CS (79.05%), JM22 (7.55%), CN16 (101.87%), YM18 (365.56%), Yangmai 20 (YM20) (10.48%), and CB301 (187.40%) were more responsive to 0.005 ‰ of H2O2, and NC4 (35.37%) obtained the highest shoot regeneration rates at 0.01 ‰ of H2O2. Overall, these two methods, inter-culture and AGP (or H2O2) application, can be further applied to wheat transgenic research.
    Characterization of starch morphology, composition, physicochemical properties and gene expressions in oat
    Zheng Ke, Jiang Qian-tao, Wei Long, Zhang Xiao-wei, Ma Jian, Chen guo-yue, Wei Yuming, Mitchell Fetch Jennifer, Lu Zhen-xiang, Zheng You-liang
    2015, 14(1): 20-28.  DOI: 10.1016/S2095-3119(14)60765-6
    Abstract ( )   PDF in ScienceDirect  
    Starch is the major carbohydrate in oat (Avena sativa L.) and starch formation requires the coordinated actions of several synthesis enzymes. In this study, the granule morphology, composition and physicochemical properties of oat starch, as well as the expressions of starch synthesis genes were investigated during oat endosperm development. Under the scanning electron microscopy (SEM), we observed that the unique compound granules were developed in oat endosperms at 10 days post anthesis (DPA) and then fragmented into irregular or polygonal simple granules from 12 DPA until seed maturity. The amylose content, branch chain length of degree of polymerization (DP=13–24), gelatinization temperature and percentage of retrogradation were gradually increased during the endosperm development; whereas the distribution of short chains (DP=6–12) were gradually decreased. The relative expressions of 4 classes of 13 starch synthesis genes characterized in this study indicated that three expression pattern groups were significantly different among gene classes as well as among varied isoforms, in which the first group of starch synthesis genes may play a key role on the initiation of starch synthesis in oat endosperms.
    Genome-wide analysis of the calcium-dependent protein kinase gene family in Gossypium raimondii
    LI Li-bei, YU Ding-wei, ZHAO Feng-li, PANG Chao-you, SONG Mei-zhen, WEI Heng-ling, FAN Shu-li, YU Shu-xun
    2015, 14(1): 29-41.  DOI: 10.1016/S2095-3119(14)60780-2
    Abstract ( )   PDF in ScienceDirect  
    Plant calcium-dependent protein kinases (CDPKs) play important roles in diverse physiological processes by regulating the downstream components of calcium signaling. To date, only a few species of the plant CDPK gene family have been functionally identified. In addition, there has been no systematic analysis of the CDPK family in cotton. Here, 41 putative cotton CDPK (GrCDPK) genes were identified via bioinformatics analysis of the entire genome of Gossypium raimondii and were classified into four groups based on evolutionary relatedness. Gene structure analysis indicated that most of these GrCDPK genes share a similar intron-exon structure (7 or 8 exons), strongly supporting their close evolutionary relationships. Chromosomal distributions and phylogenetics analysis showed that 13 pairs of GrCDPK genes arose via segmental duplication events. Furthermore, using microarray data of upland cotton (G. hirsutum L.), comparative profiles analysis of these GhCDPKs indicated that some of the encoding genes might be involved in the responses to multiple abiotic stresses and play important regulatory roles during cotton fiber development. This study is the first genome-wide analysis of the CDPK family in cotton, and it will provide valuable information for the further functional characterization of cotton CDPK genes.
    Identification of microRNAs in two species of tomato, Solanum lycopersicum and Solanum habrochaites, by deep sequencing
    FAN Shan-shan, LI Qian-nan, GUO Guang-jun, GAO Jian-chang, WANG Xiao-xuan, GUO Yanmei, John C. Snyder, DU Yong-chen
    2015, 14(1): 42-49.  DOI: 10.1016/S2095-3119(14)60821-2
    Abstract ( )   PDF in ScienceDirect  
    MicroRNAs (miRNAs) are ~21 nucleotide (nt), endogenous RNAs that regulate gene expression in plants. Increasing evidence suggests that miRNAs play an important role in species-specific development in plants. However, the detailed miRNA profile divergence has not been performed among tomato species. In this study, the small RNA (sRNA) profiles of Solanum lycopersicum cultivar 9706 and Solanum habrochaites species PI 134417 were obtained by deep sequencing. Sixty-three known miRNA families were identified from these two species, of which 39 were common. Further miRNA profile comparison showed that 24 known non-conserved miRNA families were species-specific between these two tomato species. In addition, six conserved miRNA families displayed an apparent divergent expression pattern between the two tomato species. Our results suggested that species-specific, non-conserved miRNAs and divergent expression of conserved miRNAs might contribute to developmental changes and phenotypic variation between the two tomato species. Twenty new miRNAs were also identified in S. lycopersicum. This research significantly increases the number of known miRNA families in tomato and provides the first set of small RNAs in S. habrochaites. It also suggests that miRNAs have an important role in species-specific plant developmental regulation.
    A possible mechanism of mineral responses to elevated atmospheric CO2 in rice grains
    GUO Jia, ZHANG Ming-qian, WANG Xiao-wen, ZHANG Wei-jian
    2015, 14(1): 50-57.  DOI: 10.1016/S2095-3119(14)60846-7
    Abstract ( )   PDF in ScienceDirect  
    Increasing attentions have been paid to mineral concentration decrease in milled rice grains caused by CO2 enrichment, but the mechanisms still remain unclear. Therefore, mineral (Ca, Mg, Fe, Zn and Mn) translocation in plant-soil system with a FACE (Free-air CO2 enrichment) experiment were investigated in Eastern China after 4-yr operation. Results mainly showed that: (1) elevated CO2 significantly increased the biomass of stem and panicle by 21.9 and 24.0%, respectively, but did not affect the leaf biomass. (2) Elevated CO2 significantly increased the contents of Ca, Mg, Fe, Zn, and Mn in panicle by 61.2, 28.9, 87.0, 36.7, and 66.0%, respectively, and in stem by 13.2, 21.3, 47.2, 91.8, and 25.2%, respectively, but did not affect them in leaf. (3) Elevated CO2 had positive effects on the weight ratio of mineral/biomass in stem and panicle. Our results suggest that elevated CO2 can favor the translocation of Ca, Mg, Fe, Zn, and Mn from soil to stem and panicle. The CO2-led mineral decline in milled rice grains may mainly attribute to the CO2-led unbalanced stimulations on the translocations of minerals and carbohydrates from vegetative parts (e.g., leaf, stem, branch and husk) to the grains.
    Soil mulching can mitigate soil water deficiency impacts on rainfed maize production in semiarid environments
    ZHU Lin, LIU Jian-liang, LUO Sha-sha, BU Ling-duo, CHEN Xin-ping; LI Shi-qing
    2015, 14(1): 58-66.  DOI: 10.1016/S2095-3119(14)60845-5
    Abstract ( )   PDF in ScienceDirect  
    Temporally irregular rainfall distribution and inefficient rainwater management create severe constraints on crop production in rainfed semiarid areas. Gravel and plastic film mulching are effective methods for improving agricultural productivity and water utilization. However, the effects of these mulching practices on soil water supply and plant water use associated with crop yield are not well understood. A 3-yr study was conducted to analyze the occurrence and distribution of dry spells in a semiarid region of Northwest China and to evaluate the effects of non-mulching (CK), gravel mulching (GM) and plastic film mulching (FM) on the soil water supply, plant water use and maize (Zea mays L.) grain yield. Rainfall analysis showed that dry spells of ≥5 days occurred frequently in each of 3 yr, accounting for 59.9–69.2% of the maize growing periods. The >15-d dry spells during the jointing stage would expose maize plants to particularly severe water stress. Compared with the CK treatment, both the GM and FM treatments markedly increased soil water storage during the early growing season. In general, the total evapotranspiration (ET) was not significantly different among the three treatments, but the mulched treatments significantly increased the ratio of pre- to post-silking ET, which was closely associated with yield improvement. As a result, the grain yield significantly increased by 17.1, 70.3 and 16.7% for the GM treatment and by 28.3, 87.6 and 38.2% for the FM treatment in 2010, 2011 and 2012, respectively, compared with the CK treatment. It’s concluded that both GM and FM are effective strategies for mitigating the impacts of water deficit and improving maize production in semiarid areas. However, FM is more effective than GM.
    Effects of root restriction on nitrogen and gene expression levels in nitrogen metabolism in Jumeigui grapevines (Vitis vinifera L.×Vitis labrusca L.)
    YU Xiu-ming, LI Jie-fa, ZHU Li-na, WANG Bo, WANG Lei, BAI Yang, ZHANG Cai-xi, XU Wen-ping, WANG Shi-ping
    2015, 14(1): 67-79.  DOI: 10.1016/S2095-3119(14)60876-5
    Abstract ( )   PDF in ScienceDirect  
    To decipher the relationship between the inhibited shoot growth and expression pattern of key enzymes in nitrogen metabolism under root restriction, the effects of root restriction on diurnal variation of expression of nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS1-1, GS1-2, GS2) and glutamate synthase (Fd-GOGAT, NADH-GOGAT) genes and nitrogen levels were evaluated in two-year-old Jumeigui grapevines (Vitis vinifera L.×Vitis labrusca L.) when significant differences in shoot growth were observed between treatments at expansion stage (22 days after anthesis). Grapevines were planted in root-restricting pits as root restriction and in an unrestricted field as the control. Results showed that root restriction significantly reduced shoot growth, but promoted the growth of white roots and fibrous brown roots and improved the fruit quality. (NO3 –+NO2 –)-N concentration in all plant parts, NH4 +-N concentration in white roots and total N concentration in leaves and brown roots were significantly reduced under root restriction. Gene expression analysis revealed that mRNA levels of genes related to the GS1/NADH-GOGAT pathway were lower in root-restricted than in control petioles, whereas genes involved in the GS2/Fd-GOGAT pathway were up-regulated under root restriction. Root restriction also resulted in downregulation of genes involved in nitrogen metabolism in leaves, especially at 10:00, while transcript levels of all these genes were enhanced in root-restricted white and brown roots at most time points. This organ-dependent response contributed to the alteration in NO3 – reduction and NH4 + assimilation under root restriction, leading to less NO3 – transported from roots and then assimilated in root-restricted leaves. Therefore, this study implied that shoot growth inhibition in grapevines under root restriction is closely associated with down-regulation of gene expression in nitrogen metabolism in leaves.
    Plant Protection
    Secondary metabolites of rice sheath blight pathogen Rhizoctonia solani Kühn and their biological activities
    XU Liang, WANG Xiao-han, LUO Rui-ya, LU Shi-qiong, GUO Ze-jian, WANG Ming-an, LIU Yang, ZHOU Li-gang
    2015, 14(1): 80-87.  DOI: 10.1016/S2095-3119(14)60905-9
    Abstract ( )   PDF in ScienceDirect  
    Eight compounds were isolated from the fermentation cultures of rice sheath blight pathogen Rhizoctonia solani Kühn. They were identified as ergosterol (1), 6β-hydroxysitostenone (2), sitostenone (3), m-hydroxyphenylacetic acid (4), methyl m-hydroxyphenylacetate (5), m-hydroxymethylphenyl pentanoate (6), (Z)-3-methylpent-2-en-1,5-dioic acid (7) and 3-methoxyfuran-2-carboxylic acid (8) by means of physicochemical and spectroscopic analysis. Among them, 2, 3, 5–8 were isolated from R. solani for the first time. All the compounds were evaluated for their biological activities. 4–6 and 8 showed their inhibitory activities on the radical and germ elongation of rice seeds. 1, 4 and 7 showed moderate antibacterial activity to some bacteria. 4, 7 and 8 exhibited weak inhibitory activities on spore germination of Magnaporthe oryzae. 8 showed moderate antioxidant activity with the 1,1-diphenyl-2-picryhydrazyl (DPPH) and β-carotene-linoleic acid assays. This is the first time to reveal compounds 5, 6 and 8 from rice sheath blight pathogen R. solani to have in vitro phytotoxic activity.
    Allelopathy of decomposed maize straw products on three soilborn diseases of wheat and the analysis by GC-MS
    QI Yong-zhi, ZHEN Wen-chao, LI Hai-yan
    2015, 14(1): 88-97.  DOI: 10.1016/S2095-3119(14)60795-4
    Abstract ( )   PDF in ScienceDirect  
    In northern China, the soil-born diseases of wheat have been getting more and more serious under a new farming system that returns maize straw to the field. In order to investigate the allelopathy of the decomposed maize straw products on three soil-born diseases of wheat, culture dish and pot experiments were conducted and the compounds in the products were identified by gas chromatography-mass spectrometry (GC-MS). Culture dish experiments showed that the mycelial growth, sclerotia formation amount and total weight of Rhizoctonia cerealis were promoted at concentrations of 0.03, 0.06 and 0.12 g mL–1 and inhibited at concentration of 0.48 g mL–1 of the decomposed products. No significant effects were found of the product concentrations on average weight of the sclerotia. Mycelial growth of Gaeumannomyces graminis was promoted at almost all concentrations except the highest one. Mycelial growth and spore germination of Bipolaris sorokiniana were significantly inhibited by all concentrations of the decomposed products, with enhanced inhibition effects along with the increased concentrations. The length, number and dry weight of roots together with the root superoxide dismutase activity were promoted by the lowest concentration (0.03 g mL–1), with a synthetic effect index of 0.012, and inhibited by other concentrations. The ion leakage of roots was increased and the root peroxidase activity of roots was lowered by all the treatments. Pot experiments revealed that occurrence of the sharp eyespot was reduced by 0.03 and 0.06 g mL–1 of decomposed products after irrigation. However, the incidence rates and disease indexes were significantly increased by 0.12, 0.24 and 0.48 g mL–1 of decomposed products. The results indicated that incidence rates and disease indexes of the take-all were significantly promoted after being irrigated with the decomposed products, while occurrences of the common rot didn’t change, significantly. GC-MS results showed that the compounds of the decomposed products included organic acids, esters, hydrocarbons, amides and aldehydes, with the proportions 25.26, 24.01, 17.22, 14.39 and 7.73%, respectively. Further analysis investigated that the allelochemicals identified in straw decomposed products contained p-hydroxybenzoic acid (9.21%), dibutyl phthalate (6.94%), 3-phenyl-2-acrylic (5.06%), 4-hydroxy-3,5-dimethoxybenzoic acid (2.26%), hexanoic acid (1.73%), 8-octadecenoic acid (1.06%), 3-(4-hydroxy-3-methoxy-phenyl)-2-propenoic acid (1.04%), 4-hydroxy-3-methoxy-benzoic acid (0.94%) and salicylic acid (0.94%).
    Compatibility of Beauveria bassiana with Neoseiulus barkeri for Control of Frankliniella occidentalis
    WU Sheng-yong, GAO Yu-lin, XU Xue-nong, Mark S Goettel, LEI Zhong-ren
    2015, 14(1): 98-105.  DOI: 10.1016/S2095-3119(13)60731-5
    Abstract ( )   PDF in ScienceDirect  
    The entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin and predatory mite Neoseiulus barkeri Hughes are effective biological control agents of Frankliniella occidentalis Pergande (Thysanoptera: Thripidae), one of the most important pests of ornamentals and vegetables world-wide. Combined application of both may enhance control efficiency. The functional response for N. barkeri on the first instar larvae of western flower thrips which were infected by B. bassiana for 12 and 24 h in the laboratory ((25±1)°C, (70±5)% RH, L:D=16 h:8 h) was determined. The virulence of B. bassiana against the second instar and pupae of the thrips attacked by N. barkeri were also tested. The results showed that N. barkeri exhibited a Holling type II functional response on treated thrips. After having been treated with the fungus for 12 h and then offered to the predator, thrips were more vulnerable to be killed by N. barkeri. The second instar larvae and pupae of the thrips which had been attacked by predatory mites were markedly more susceptible to B. bassiana infection than normal thrips; the cumulative corrected mortality of B. bassiana of the second instar and pupae which were attacked by N. barkeri were 57 and 94%, respectively, compared to 35 and 80% in controls on the day 8. These findings highlight the potential use of B. bassiana in combination with N. barkeri to control F. occidentalis.
    Dissipation and residue of ethephon in maize field
    DONG Jian-nan, MA Yong-qiang, LIU Feng-mao, JIANG Nai-wen, JIAN Qiu
    2015, 14(1): 106-113.  DOI: 10.1016/S2095-3119(14)60768-1
    Abstract ( )   PDF in ScienceDirect  
    A rapid and reliable method was developed for analysis of ethephon residues in maize, in combination with the investigation of its dissipation in field condition and stabilities during the sample storage. The residue analytical method in maize plant, maize kernel and soil was developed based on the quantification of ethylene produced from the derivatization of ethephon residue by adding the saturated potassium hydroxide solution to the sample. The determination was carried out by using the head space gas chromatography with flame ionization detector (HS-GC-FID). The limit of quantification (LOQ) of the method for maize plant was 0.05, 0.02 mg kg–1 for maize kernel and 0.05 mg kg–1 for soil, respectively. The fortified recoveries of the method were from 84.6–102.6%, with relative standard deviations of 7.9–3.8%. Using the methods, the dissipation of ephethon in maize plant or soil was investigated. The half life of ethephon degradation was from 0.6 to 3.3 d for plant and 0.7 to 5.7 d for soil, respectively. The storage stabilities of ethephon residues were determined in fresh and dry kernels with homogenization and without homogenization process. And the result showed that ethephon residues in maize kernels were stable under –18°C for 6 mon. The results were helpful to monitor the residue dissipation of ethephon in the maize ecosystem for further ecological risk assessment.
    Impact of fluxapyroxad on the microbial community structure and functional diversity in the silty-loam soil
    WU Xiao-hu, XU Jun, LIU Yong-zhuo, DONG Feng-shou, LIU Xin-gang, ZHANG Wen-wen, ZHENG Yong-quan
    2015, 14(1): 114-124.  DOI: 10.1016/S2095-3119(14)60746-2
    Abstract ( )   PDF in ScienceDirect  
    The aim of this work was to assess the effect of applying three different doses of fluxapyroxad on microbial activity, community structure and functional diversity as measured by respiration, microbial biomass C, phospholipid fatty acid (PLFA) and community-level physiological profiles (CLPPs). Our results demonstrated that substrate-induced respiration (on day 15) and microbial biomass C (on days 7 and 15) were inhibited by fluxapyroxad, but stimulation was observed thereafter. In contrast, fluxapyroxad addition increased the basal respiration and metabolic quotients (qCO2) and respiratory quotients (QR). Analysis of the PLFA profiles revealed that the total and bacterial biomass (both Gram-positive bacteria (GP) and Gram-negative bacteria (GN)) were decreased within the initial 15 days, whereas those as well as the GN/GP ratio were increased at days 30 and 60. Fluxapyroxad input decreased the fungi biomass but increased the bacteria/fungi ratio at all incubation time. Moreover, high fluxapyroxad input (75 mg fluxapyroxad kg–1 soil dry weight) increased the microbial stress level. A principal component analysis (PCA) of the PLFAs revealed that fluxapyroxad treatment significantly shifted the microbial community structure, but all of the observed effects were transient. Biolog results showed that average well color development (AWCD) and functional diversity index (H´) were increased only on day 60. In addition, the dissipation of fluxapyroxad was slow in soil, and the degradation half-lives varied from 158 to 385 days depending on the concentration tested.
    Animal Science · Veterinary Science
    Genetic parameters for somatic cell score and production traits in the first three lactations of Chinese Holstein cows
    ZHAO Fu-ping, GUO Gang, WANG Ya-chun, GUO Xiang-yu, ZHANG Yuan, DU Li-xin
    2015, 14(1): 125-130.  DOI: 10.1016/S2095-3119(14)60758-9
    Abstract ( )   PDF in ScienceDirect  
    The objectives of this study were to estimate genetic parameters of lactation average somatic cell scores (LSCS) and examine genetic associations between LSCS and production traits in the first three lactations of Chinese Holstein cows using single-parity multi-trait animal model and multi-trait repeatability animal model. There were totally 273 605 lactation records of Chinese Holstein cows with first calving from 2001 to 2012. Heritability estimates for LSCS ranged from 0.144 to 0.187. Genetic correlations between LSCS and 305 days milk, protein percentage and fat percentage were –0.079, –0.082 and –0.135, respectively. Phenotypic correlation between LSCS and 305 days milk yield was negative (–0.103 to –0.190). Genetic correlation between 305 days milk and fat percentage or protein percentage was highly negative. Genetic correlation between milk fat percentage and milk protein percentage was highly favorable. Heritabilities of production traits decreased with increase of parity, whereas heritability of LSCS increased with increase of parity.
    Effects of cellulase and xylanase enzymes mixed with increasing doses of Salix babylonica extract on in vitro rumen gas production kinetics of a mixture of corn silage with concentrate
    Abdelfattah Z M Salem, German Buendía-Rodríguez, Mona M M Elgh, our , María A Mariezcurrena Berasain, Francisco J Pe?a Jiménez, Alberto B Pliego, Juan C V Chagoyán, María A Cerrillo, Miguel A Rodríguez
    2015, 14(1): 131-139.  DOI: 10.1016/S2095-3119(13)60732-7
    Abstract ( )   PDF in ScienceDirect  
    An in vitro gas production (GP) technique was used to investigate the effects of combining different doses of Salix babylonica extract (SB) with exogenous fibrolytic enzymes (EZ) based on xylanase (X) and cellulase (C), or their mixture (XC; 1:1 v/v) on in vitro fermentation characteristics of a total mixed ration of corn silage and concentrate mixture (50:50, w/w) as substrate. Four levels of SB (0, 0.6, 1.2 and 1.8 mL g–1 dry matter (DM)) and four supplemental styles of EZ (1 μL g–1 DM; control (no enzymes), X, C and XC (1:1, v/v) were used in a 4×4 factorial arrangement. In vitro GP (mL g–1 DM) were recorded at 2, 4, 6, 8, 10, 12, 24, 36, 48 and 72 h of incubation. After 72 h, the incubation process was stopped and supernatant pH was determined, and then filtered to determine dry matter degradability (DMD). Fermentation parameters, such as the 24 h gas yield (GY24), in vitro organic matter digestibility (OMD), metabolizable energy (ME), short chain fatty acid concentrations (SCFA), and microbial crude protein production (MCP) were also estimated. Results indicated that there was a SB´EZ interaction (P<0.0001) for the asymptotic gas production (b), the rate of gas production (c), GP from 6 to 72 h, GP2 (P=0.0095), and GP4 (P=0.02). The SB and different combination of enzymes supplementation influenced (P<0.001) in vitro GP parameters after 12 h of incubation; the highest doses of SB (i.e., 1.8 mL g–1 DM), in the absence of any EZ, quadratically increased (P<0.05) the initial delay before GP begins (L) and GP at different incubation times, with lowering b (quadratic effect, P<0.0001) and c (quadratic effect, P<0.0001; linear effect, P=0.0018). The GP was the lowest (P<0.05) when the highest SB level was combined with cellulose. There were SB´EZ interactions (P<0.001) for OMD, ME, the partitioning factor at 72 h of incubation (PF72), GY24, SCFA, MCP (P=0.0143), and pH (P=0.0008). The OMD, ME, GY24 and SCFA with supplementation of SB extract at 1.8 mL g–1 DM were higher (P<0.001) than the other treatments, however,PF72 was lower (quadratic effect, P=0.0194) than the other levels. Both C and X had no effect (P>0.05) on OMD, pH, ME, GY24, SCFA and MP. The combination of SB with EZ increased (P<0.001) OMD, ME, SCFA, PF72 and GP24, whereas there was no impact on pH. It could be concluded that addition of SB extract, C, and X effectively improved the in vitro rumen fermentation, and the combination of enzyme with SB extract at the level of 1.2 mL g–1 was more effective than the other treatments.
    Luteolin prevents fMLP-induced neutrophils adhesion via suppression of LFA-1 and phosphodiesterase 4 activity
    JIANG Dai-xun, LIU Shu-rong, ZHANG Mei-hua, ZHANG Tao, MA Wen-jing, MU Xiang, CHEN Wu
    2015, 14(1): 140-147.  DOI: 10.1016/S2095-3119(14)60904-7
    Abstract ( )   PDF in ScienceDirect  
    Luteolin is an active ingredient found early from Folium perillae and Flos lonicerae, and has a specific inhibition on phosphodiesterase 4 (PDE4) activity in vitro. Researches show luteolin has pharmacological effects of anti-inflammation, anti-anaphylaxis, antitumor, antioxidant, protection of nervous system and so on, and has mainly been used for the treatment of respiratory inflammatory diseases, cancer and cardiovascular disease in clinic. PDE4, specific to hydrolyze cyclic AMP (cAMP), is considered to be a new anti-inflammatory target due to the decisive role on cAMP signal in inflammatory cells such as neutrophils. In order to explore the anti-inflammatory mechanism, we further studied the effects of luteolin on the activity and expression of PDE4, the expression of lymphocyte function-associated antigen-1 (LFA-1) and macrophage-1 (MAC-1) in neutrophils, and the adhesion of neutrophils and endothelial cells. The results showed that luteolin had a dose-dependent inhibition on both bare PDE4 activity and PDE4 in cultured neutrophils, and had an obviously promotive effect on gene expressions of PDE4A, 4B and 4D in later period. Luteolin had a significant inhibitory effect on neutrophils adhesion and LFA-1 expression in early stage, and had no obvious effect on MAC-1 expression. Therefore, luteolin can inhibit LFA-1 expression of neutrophils, then inhibit the adhesion of neutrophils and endothelial cells, and the mechanism is at least related with the inhibition of PDE4 activity.
    Soil & Fertilization · Irrigation · Agro-Ecology & Environment
    Proton accumulation accelerated by heavy chemical nitrogen fertilization and its long-term impact on acidifying rate in a typical arable soil in the Huang-Huai-Hai Plain
    HUANG Ping, ZHANG Jia-bao, XIN Xiu-li, ZHU An-ning, ZHANG Cong-zhi, MA Dong-hao, ZHU Qiang-gen, YANG Shan, WU Sheng-jun
    2015, 14(1): 148-157.  DOI: 10.1016/S2095-3119(14)60750-4
    Abstract ( )   PDF in ScienceDirect  
    Cropland productivity has been significantly impacted by soil acidification resulted from nitrogen (N) fertilization, especially as a result of excess ammoniacal N input. With decades’ intensive agricultural cultivation and heavy chemical N input in the Huang-Huai-Hai Plain, the impact extent of induced proton input on soil pH in the long term was not yet clear. In this study, acidification rates of different soil layers in the soil profile (0–120 cm) were calculated by pH buffer capacity (pHBC) and net input of protons due to chemical N incorporation. Topsoil (0–20 cm) pH changes of a long-term fertilization field (from 1989) were determined to validate the predicted values. The results showed that the acid and alkali buffer capacities varied significantly in the soil profile, averaged 692 and 39.8 mmolc kg–1 pH–1, respectively. A significant (P<0.05) correlation was found between pHBC and the content of calcium carbonate. Based on the commonly used application rate of urea (500 kg N ha–1 yr–1), the induced proton input in this region was predicted to be 16.1 kmol ha–1 yr–1, and nitrification and plant uptake of nitrate were the most important mechanisms for proton producing and consuming, respectively. The acidification rate of topsoil (0–20 cm) was estimated to be 0.01 unit pH yr–1 at the assumed N fertilization level. From 1989 to 2009, topsoil pH (0–20 cm) of the long-term fertilization field decreased from 8.65 to 8.50 for the PK (phosphorus, 150 kg P2O5 ha–1 yr–1; potassium, 300 kg K2O ha–1 yr–1; without N fertilization), and 8.30 for NPK (nitrogen, 300 kg N ha–1 yr–1; phosphorus, 150 kg P2O5 ha–1 yr–1; potassium, 300 kg K2O ha–1 yr–1), respectively. Therefore, the apparent soil acidification rate induced by N fertilization equaled to 0.01 unit pH yr–1, which can be a reference to the estimated result, considering the effect of atmospheric N deposition, crop biomass, field management and plant uptake of other nutrients and cations. As protons could be consumed by some field practices, such as stubble return and coupled water and nutrient management, soil pH would maintain relatively stable if proper management practices can be adopted in this region.
    Preparation and utilization of phosphate biofertilizers using agricultural waste
    WANG Hong-yuan, LIU Shen, ZHAI Li-mei, ZHANG Ji-zong, REN Tian-zhi, FAN Bing-quan, LIU Hong-bin
    2015, 14(1): 158-167.  DOI: 10.1016/S2095-3119(14)60760-7
    Abstract ( )   PDF in ScienceDirect  
    In this study, Aspergillus niger 1107 was isolated and identified as an efficient phosphate-solubilizing fungus (PSF). This strain generated 689 mg soluble P L–1 NBRIP medium after 10 d of culture. To produce an affordable biofertilizer using A. niger 1107, the potential of widely available carrier materials for growth and maintenance of this strain were evaluated. The effects of sterilization procedures (autoclaving and gamma-ray irradiation) on the suitability of these carriers to maintain growth of the fungus were also investigated. The carrier materials were peat, corn cobs with 20% (w/w) perlite (CCP), wheat husks with 20% (w/w) perlite (WHP), and composted cattle manure with 20% (w/w) perlite (CCMP). In the first 5-6 mon of storage, the carriers sterilized by gamma-ray irradiation maintained higher inoculum loads than those in carriers sterilized by autoclaving. However, this effect was not detectable after 7 mon of storage. For the P-biofertilizer on WHP, more than 2.0×107 viable spores of A. niger g–1 inoculant survived after 7 mon of storage. When this biofertilizer was applied to Chinese cabbage in a pot experiment, there were 5.6×106 spores of A. niger g–1 soil before plant harvesting. In the pot experiment, Chinese cabbage plants grown in soil treated with peat- and WHP-based P-biofertilizers showed significantly greater growth (P<0.05) than that of plants grown in soil treated with free-cell biofertilizer or the CCMP-based biofertilizer. Also, the peat- and WHP-based P-biofertilizers increased the available P content in soil.
    Adsorption of Cu(II) on humic acids derived from different organic materials
    LI Cui-lan, JI Fan, WANG Shuai, ZHANG Jin-jing, GAO Qiang, WU Jing-gui, ZHAO Lan-po, WANG Li-chun, ZHENG Li-rong
    2015, 14(1): 168-177.  DOI: 10.1016/S2095-3119(13)60682-6
    Abstract ( )   PDF in ScienceDirect  
    The adsorption of Cu(II) from aqueous solution onto humic acid (HA) which was isolated from cattle manure (CHA), peat (PHA), and leaf litter (LHA) as a function of contact time, pH, ion strength, and initial concentration was studied using the batch method. X-ray absorption spectroscopy (XAS) was used to examine the coordination environment of the Cu(II) adsorbed by HA at a molecular level. Moreover, the chemical compositions of the isolated HA were characterized by elemental analysis and solid-state 13C nuclear magnetic resonance spectroscopy (NMR). The kinetic data showed that the adsorption equilibrium can be achieved within 8 h. The adsorption kinetics followed the pseudo-second-order equation. The adsorption isotherms could be well fitted by the Langmuir model, and the maximum adsorption capacities of Cu(II) on CHA, PHA, and LHA were 229.4, 210.4, and 197.7 mg g–1, respectively. The adsorption of Cu(II) on HA increased with the increase in pH from 2 to 7, and maintained a high level at pH>7. The adsorption of Cu(II) was also strongly influenced by the low ionic strength of 0.01 to 0.2 mol L–1 NaNO3, but was weakly influenced by high ionic strength of 0.4 to 1 mol L–1 NaNO3. The Cu(II) adsorption on HA may be mainly attributed to ion exchange and surface complexation. XAS results revealed that the binding site and oxidation state of Cu adsorbed on HA surface did not change at the initial Cu(II) concentrations of 15 to 40 mg L–1. For all the Cu(II) adsorption samples, each Cu atom was surrounded by 4 O/N atoms at a bond distance of 1.95 Å in the first coordination shell. The presence of the higher Cu coordination shells proved that Cu(II) was adsorbed via an inner-sphere covalent bond onto the HA surface. Among the three HA samples, the adsorption capacity and affinity of CHA for Cu(II) was the greatest, followed by that of PHA and LHA. All the three HA samples exhibited similar types of elemental and functional groups, but different contents of elemental and functional groups. CHA contained larger proportions of methoxyl C, phenolic C and carbonyl C, and smaller proportions of alkyl C and carbohydrate C than PHA and LHA. The structural differences of the three HA samples are responsible for their distinct adsorption capacity and affinity toward Cu(II). These results are important to achieve better understanding of the behavior of Cu(II) in soil and water bodies in the presence of organic materials.
    Applying a salinity response function and zoning saline land for three field crops: a case study in the Hetao Irrigation District, Inner Mongolia, China
    TONG Wen-jie1, CHEN Xiao-li2, WEN Xin-ya1, CHEN Fu1, ZHANG Hai-lin1, CHU Qing-quan1, Shadrack Batsile Dikgwatlhe1
    2015, 14(1): 178-189.  DOI: 10.1016/S2095-3119(14)60761-9
    Abstract ( )   PDF in ScienceDirect  
    Salinity is one of the major abiotic factors affecting the growth and productivity of crops in Hetao Irrigation District, China. In this study, the salinity tolerances of three local crops, wheat (Triticum aestinum L.), maize (Zea mays L.) and sunflower (Helianthus annuus L.), growing in 76 farm fields are evaluated with modified discount function. Salinity ecological zones appropriate for these local crops are characterized and a case study is presented for crop salinity ecological zoning. The results show that the yield reductions of wheat, maize and sunflower when grown in saline soils are attributed primarily to a reduction in spikelet number, 1 000-grain weight and seed number per head, respectively. Sunflower is the most tolerant crop among the three which had a salinity tolerance index (ST-index) of 12.24, followed by spring maize and spring wheat with ST-Indices of 9.00 and 7.43, respectively. According to the crop salinity tolerance results, the arable land in the Heping Village of this district was subdivided into four salinity ecological zones: the most suitable, suitable, sub-suitable and unsuitable zones. The area proportion of the most suitable zone for wheat, maize and sunflower within the Heping Village was 27.5, 46.5 and 77.5%, respectively. Most of the most suitable zone occurred in the western part of the village. The results of this study provide the scientific basis for optimizing the local major crop distribution and improving cultural practices management in Hetao Irrigation District.
    Short Communication
    Establishing dynamic thresholds for potato nitrogen status diagnosis with the SPAD chlorophyll meter
    ZHENG Hong-li, LIU Yan-chun, QIN Yong-lin, CHEN Yang, FAN Ming-shou
    2015, 14(1): 190-195.  DOI: 10.1016/S2095-3119(14)60925-4
    Abstract ( )   PDF in ScienceDirect  
    The hand-held soil plant analysis development (SPAD) chlorophyll meter has proved to be a promising tool in evaluating the nitrogen status of the potato and guiding fertilization recommendations. In the process of N evaluation of potato plants and N recommendation, it is critical to establish the threshold SPAD value (SPAD reading), below which nitrogen supplement is required. And taking convenient using into account, the threshold needs to be dynamic throughout the potato growing season so that the users can test their potato plants and make fertilization decision at any growing time of potato. To complete this goal, field experiments with different nitrogen supply levels were conducted in different sites in northern China from 2009 to 2011. The results showed that threshold SPAD values decrease as the growing season progresses for all cultivars and planting sites. By statistical analysis, the threshold regression models were established respectively as: y=−0.003x2−0.0507x+58.213 (y, threshold SPAD value; x, days after emergence) for the potato cultivar Kexin 1, and y=−0.003x2+0.017x+52.489 (y, threshold SPAD value; x, days after emergence) for the cultivar Shepody, from which, the threshold SPAD value at any day after emergence can be calculated.