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    Breeding wheat for drought tolerance: Progress and technologies
    Learnmore Mwadzingeni, Hussein Shimelis, Ernest Dube, Mark D Laing, Toi J Tsilo
    2016, 15(05): 935-943.  DOI: 10.1016/S2095-3119(15)61102-9
    Abstract ( )   PDF in ScienceDirect  
        Recurrent drought associated with climate change is among the principal constraints to global productivity of wheat (Triticum aestivum (L.) and T. turgidum (L.)).  Numerous efforts to mitigate drought through breeding resilient varieties are underway across the world.  Progress is, however, hampered because drought tolerance is a complex trait that is controlled by many genes and its full expression is affected by the environment.  Furthermore, wheat has a structurally intricate and large genome.  Consequently, breeding for drought tolerance requires the integration of various knowledge systems and methodologies from multiple disciplines in plant sciences.  This review summarizes the progress made in dry land wheat improvement, advances in knowledge, complementary methodologies, and perspectives towards breeding for drought tolerance in the crop to create a coherent overview.  Phenotypic, biochemical and genomics-assisted selection methodologies are discussed as leading research components used to exploit genetic variation.  Advances in phenomic and genomic technologies are highlighted as options to circumvent existing bottlenecks in phenotypic and genomic selection, and gene transfer.  The prospects of further integration of these technologies with other omics technologies are also provided.
    Crop Genetics · Breeding · Germplasm Resources
    YGL9, encoding the putative chloroplast signal recognition particle 43 kDa protein in rice, is involved in chloroplast development
    WANG Zhong-wei, ZHANG Tian-quan, XING Ya-di, ZENG Xiao-qin, WANG Ling, LIU Zhong-xian, SHI Jun-qiong, ZHU Xiao-yan, MA Ling, LI Yun-feng, LING Ying-hua, SANG Xian-chun, HE Guang-hua
    2016, 15(05): 944-953.  DOI: 10.1016/S2095-3119(15)61310-7
    Abstract ( )   PDF in ScienceDirect  
        The nuclear-encoded light-harvesting chlorophyll a/b-binding proteins (LHCPs) are specifically translocated from the stroma into the thylakoid membrane through the chloroplast signal recognition particle (cpSRP) pathway. The cpSRP is composed of a cpSRP43 protein and a cpSRP54 protein, and it forms a soluble transit complex with LHCP in the chloroplast stroma. Here, we identified the YGL9 gene that is predicted to encode the probable rice cpSRP43 protein from a rice yellow-green leaf mutant. A phylogenetic tree showed that an important conserved protein family, cpSRP43, is present in almost all green photosynthetic organisms such as higher plants and green algae. Sequence analysis showed that YGL9 comprises a chloroplast transit peptide, three chromodomains and four ankyrin repeats, and the chromodomains and ankyrin repeats are probably involved in protein-protein interactions. Subcellular localization showed that YGL9 is localized in the chloroplast. Expression pattern analysis indicated that YGL9 is mainly expressed in green leaf sheaths and leaves. Quantitative real-time PCR analysis showed that the expression levels of genes associated with pigment metabolism, chloroplast development and photosynthesis were distinctly affected in the ygl9 mutant. These results indicated that YGL9 is possibly involved in pigment metabolism, chloroplast development and photosynthesis in rice.
    Development of a core set of SNP markers for the identification of upland cotton cultivars in China
    KUANG Meng, WEI Shou-jun, WANG Yan-qin, ZHOU Da-yun, MA Lei, FANG Dan, YANG Wei-hua
    2016, 15(05): 954-962.  DOI: 10.1016/S2095-3119(15)61226-6
    Abstract ( )   PDF in ScienceDirect  
        Considering the advantages of single nucleotide polymorphisms (SNP) in genotyping and variety identification, the first set public SNP markers at Cotton Marker Database (http://www.cottonmarker.org/) were validated and screened across standard varieties of cotton distinctness, uniformity and stability (DUS) test, aiming to obtain an appropriate set of core SNP markers suitable for upland cotton cultivars in China. A total of 399 out of 1 005 SNPs from 270 loci including 170 insertions-deletions (InDels) were evaluated for their polymorphisms among 30 standard varieties using Sanger sequencing. As a result, 147 loci were sequenced successfully, 377 SNPs and 49 InDels markers were obtained. Among the 377 SNP markers, 333 markers (88.3%) were polymorphic between Gossypium hirsutum and G. barbadense, while 164 markers (43.5%) were polymorphic within upland cotton. As for InDel markers, the polymorphic rate is relatively lower than that of SNP both between species and within species. The homozygous DNA locus ratio of 121 SNPs was higher than 86.2% while that of other 43 SNPs was less than 70%. Only 64 SNPs displayed completely homozygous genotypes among all of the detected upland cotton varieties with 100% homozygous DNA locus ratio. At last, a set of 23 pairs of core SNPs were achieved in view of avoidance of linkage, with polymorphism information content (PIC) values varying from 0.21 to 0.38 with an average of 0.28. Genotype characteristics and genetic diversity were analyzed based on the set of core markers, while 40 pairs of core simple-sequence repeats (SSR) primers comprised of 10 sets of four multiplex PCR combinations were also used for analysis based on fluorescence detection system. Comparison results indicated that the genetic diversity level was almost equal, while various varieties were significantly different from each other. Genetic relationship revealed by SSR markers is related to geographic source to a certain extent. Meanwhile clustering results analyzed by SNP markers are more consistent with kinship, which demonstrated that the screen strategy for core SNP marker is effective.
    Stability of growth periods traits for soybean cultivars across multiple locations
    WANG Xiao-bo, LIU Zhang-xiong, YANG Chun-yan, XU ran, LU Wei-guo, ZHANG Li-feng, WANG Qian, WEI Su-hong, YANG Chun-ming, WANG Hui-cai, WANG Rui-zhen, ZHOU Rong, CHEN Huaizhu, CHANG Ru-zhen, QIU Li-juan
    2016, 15(05): 963-972.  DOI: 10.1016/S2095-3119(15)61152-2
    Abstract ( )   PDF in ScienceDirect  
        The growth periods (GPs, from planting/emergence to reproductive stage 8 (R8) of soybean cultivars vary in different ecological regions, especially in China with a very complex soybean cropping system. In this study, a 3-yr experimental study was undertaken in three geographical locations of China from 2008 to 2010, including the Northeast (40.66–45.85°N), Huang-Huai (34.75–38.04°N) and southern (22.82–30.60°N) eco-regions with about 250 accessions in each region to clarify the classification of maturity group (MG) and identify the cultivars with stable GP to increase the knowledge about the GP distribution of soybean cultivars in China. GPs of soybean cultivars in different eco-regions were significant different with a gradual decrease from 115–125 d in the Northeast part to the 85–100 d in the southern part of China. The geographical location was the major factor for GP of cultivars from the Northeast, while the year of planting was the major factor affecting the stability of GPs in Huang-Huai summer and southern summer soybean. AMMI2 (additive main effects and multiplicative interaction)-Biplot analysis showed that the GPs of soybean cultivars from the Northeast eco-region have a comparatively satisfactory environmental stability. Moreover, soybean cultivars with moderate GP/MG and stable environment adaptability in different eco-regions were identified based on the linear regression and AMMI analysis, which was important for the accurate classification of soybean MGs in future. Taken together, our results reflected the genetic diversity, geographical distribution and environmental stability of the Chinese soybean GP trait. Soybean cultivars with stable GP for various Chinese eco-regions would be beneficial for Chinese soybean genetic improvement, varietal introduction, exchange, and soybean breeding program for wide adaptability.
    Cloning of the OAT gene and the correlation between its expression and drought tolerance in Phaseolus vulgaris L.
    CHEN Ji-bao, CAO Yuan-nan, ZHANG Zhao-yuan, WANG Shu-min, WU Jing, WANG Lan-fen
    2016, 15(05): 973-982.  DOI: 10.1016/S2095-3119(15)61283-7
    Abstract ( )   PDF in ScienceDirect  
    Drought stress is a major abiotic stress of common bean (Phaseolus vulgaris L.) throughout the world. Increasing the proline accumulation contributes to enhance crop drought tolerance. A cDNA for δ-ornithine aminotransferase (δ-OAT), an enzyme involved in the biosynthesis of proline, was isolated from Phaseolus vulgaris (PvOAT). PvOAT exhibits 87.4 and 39.8% similarity of the deduced amino acid sequences with δ-OAT from Glycine max and Vigna aconitifolia, respectively. The transcriptional analysis revealed that PvOAT was strongly induced by drought stress. And the expression of PvOAT was higher in leaves than that in the root and stem of common bean by drought stress. Similar increase of the proline accumulation was observed in leaves and roots of common bean by drought stress. Furthermore, the proline content, the PvOAT expression and the PvOAT enzyme activity in cultivar F5575 was significantly (P<0.01) higher than that in cultivar F4851 under drought-stress conditions. Interestingly, it had been observed that, in the later stage of drought stress, the proline steadily maintained at the maximum level maybe result from the PvOAT enzyme activity increasing steadily. These results indicated that the expression of PvOAT and the accumulation of proline induced by drought stress treatment were related to the degree of common bean drought tolerance. So our results support the view that δ-OAT is associated with proline synthesis under drought stress conditions.
    Genome-wide analysis of the synonymous codon usage patterns in apple
    LI Ning, SUN Mei-hong, JIANG Ze-sheng, SHU Huai-rui, ZHANG Shi-zhong
    2016, 15(05): 983-991.  DOI: 10.1016/S2095-3119(16)61333-3
    Abstract ( )   PDF in ScienceDirect  
    Apple (Malus×domestica) has been proposed as an important woody plant and the major cultivated fruit trees in temperate regions. Apple whole genome sequencing has been completed, which provided an excellent opportunity for genome-wide analysis of the synonymous codon usage patterns. In this study, a multivariate bioinformatics analysis was performed to reveal the characteristics of synonymous codon usage and the main factors affecting codon bias in apple. The neutrality, correspondence, and correlation analyses were performed by CodonW and SPSS (Statistical Product and Service Solutions) programs, indicating that the apple genome codon usage patterns were affected by mutational pressure and selective constraint. Meanwhile, coding sequence length and the hydrophobicity of proteins could also influence the codon usage patterns. In short, codon usage pattern analysis and determination of optimal codons has laid an important theoretical basis for genetic engineering, gene prediction and molecular evolution studies in apple.
    Top-dressing nitrogen fertilizer rate contributes to decrease culm physical strength by reducing structural carbohydrate content in japonica rice
    ZHANG Wu-jun, WU Long-mei, DING Yan-feng, WENG Fei, WU Xiao-ran, LI Gang-hua, LIU Zhenghui, TANG She, DING Cheng-qiang, WANG Shao-hua
    2016, 15(05): 992-1004.  DOI: 10.1016/S2095-3119(15)61166-2
    Abstract ( )   PDF in ScienceDirect  
    Lodging is an important factor limiting rice yield and quality by bending or breaking stem in japonica rice (Oryza sativa L.) production. The objectives of this study were to determine the mechanism of lodging resistance in japonica rice as affected by carbohydrate components, especially its related arrangement in culm tissue and response to top-dressing nitrogen (N) fertilizer. Field experiments were conducted in Danyang County, Jiangsu Province, China, by using two japonica rice varieties Wuyunjing 23 (lodging-resistance variety) and W3668 (lodging-susceptible variety) with three top-dressing N fertilizer rates (0, 135 and 270 kg N ha–1) in 2013 and 2014. Lodging related physical parameters, morphological characteristics and stem carbohydrate components were investigated at 30 d after full heading stage. Results showed that with increasing N fertilizer rates, the lodging rate and lodging index increased rapidly primarily due to significant reduction of breaking strength in two japonica rice varieties. Correlation analysis revealed that breaking strength was significantly and positively correlated with bending stress, but negatively correlated with section modulus, except for significant correlation at W3668 in 2014. Higher stem plumpness status and structural carbohydrate contents significantly enhanced stem stiffness, despite of lower non-structural carbohydrate. With higher N fertilizer rate, the culm wall thickness was almost identical, and culm diameter increased slightly. The structural carbohydrates, especially for lignin content in culm, reduced significantly under high N rate. Further histochemical staining analysis revealed that high N treatments decreased the lignin deposition rapidly in the sclerenchyma cells of mechanical tissue, large vascular bundle and small vascular bundle region, which were consistent with reduction of bending stress, especially for W3668 and thus, resulted in poor stem strength and higher lodging index. These results suggested that structural carbohydrate plays a vital role for improving stem strength in japonica rice. N rate decreased lodging resistance primarily due to poor stem stiffness, by reducing structural carbohydrate content and lignin deposition in the secondary cell wall of lower internode culm tissue.
    Comparative proteomic analysis provides new insights into ear leaf senescence of summer maize (Zea mays L.) under fild condition
    WEI Shan-shan, WANG Xiang-yu, LIU Peng, ZHANG Ji-wang, ZHAO Bin, DONG Shu-ting
    2016, 15(05): 1005-1016.  DOI: 10.1016/S2095-3119(15)61163-7
    Abstract ( )   PDF in ScienceDirect  
    As the most important organ in plant photosynthesis, the leaf plays an important role in plant growth and development. Leaf senescence is associated with fundamental changes in the proteome. To research the molecular mechanisms of leaf senescence, protein expression in senescing maize ear leaves grown under field conditions was analyzed using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionisation time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF MS). A total of 60 senescence-associated proteins were identified. The identified proteins are involved in many biological processes, especially energy, metabolism and protein synthesis. Several of the identified proteins have not been previously reported as senescence-associated, including glycine-rich RNA-binding protein.
    Grafting affects yield and phenolic profie of Solanum melongena L. landraces
    L Sabatino, G Iapichino, A Maggio, E D’ Anna, M Bruno, F D’ Anna
    2016, 15(05): 1017-1024.  DOI: 10.1016/S2095-3119(15)61323-5
    Abstract ( )   PDF in ScienceDirect  
    The influence of grafting on agronomical and qualitative characteristics of four Sicilian eggplant landraces was investigated. Grafted and ungrafted plants were compared in the open field in the northern coast of Sicily. Solanum torvum seedlings were used as rootstock. Regardless of genotypes tested, grafting significantly increased total fruit production, marketable production, and number of marketable fruits, but did not affect weight of marketable fruits and waste production. Landrace 2 (Sciacca), with black epidermal tissue and pyriform fruit shape, when grafted onto S. torvum not only gave a higher yield performance than ungrafted plants, but also showed a higher phenolic antioxidant content. Landrace 4 (Sicilia), with black epidermal tissue and small cylindrical fruits also benefited, when grafted onto S. torvum, from a substantial increase in antioxidant fruit content. As consumers’ demand for fruits and vegetables rich in compounds important for human health is steadily increasing, these landrace/rootstock combinations should deserve more attention by plant nurseries involved in grafted seedling production and interested in the valorization and conservation of eggplant biodiversity.
    Dwarfing apple rootstock responses to elevated temperatures: A study on plant physiological features and transcription level of related genes
    ZHOU Bei-bei, SUN Jian, LIU Song-zhong, JIN Wan-mei, ZHANG Qiang, WEI Qin-ping
    2016, 15(05): 1025-1033.  DOI: 10.1016/S2095-3119(15)61298-9
    Abstract ( )   PDF in ScienceDirect  
      The aim of this study was to investigate the impact of heat stress on physiological features, together with endogenous hormones and the transcription level of related genes, to estimate the heat resistance ability and stress injury mechanism of different dwarfig apple rootstocks. Among the six rootstocks, the rootstocks of native Shao series (SH series) showed better heat stress resistance than those of Budagovski 9 (B9), Cornell-Geneva 24 (CG24), and Malling 26 (M26) from abroad. Among SH series rootstocks, SH1 and SH6 showed higher heat stress resistance than SH40. M26 demonstrated the lowest adaption ability to heat stress, showing higher leaf conductivity and lower liquid water content (LWC) with the increase in temperature. Heat stress also resulted in the suppression of photosynthesis, which showed no signifiant restoration after 7-day recovery. It should be noted that although a higher temperature led to a lower LWC and photosynthetic effiiency (Pn ) of CG24, there was no signifiant increase in leaf conductivity, and 7 days after the treatment, the Pn of CG24 recovered. The extremely high temperature tolerance of SH series rootstocks could be related to the greater osmotic adjustment (OA), which was reflcted by smaller reductions in leaf relative water content (RWC) and higher turgor potentials and leaf gas exchange compared with the other rootstocks. Determination of hormones indicated multivariate regulation, and it is presumed that a relatively stable expression levels of functional genes under high-temperature stress is necessary for heat stress resistance of rootstocks
    Plant Protection
    Sclerotinia sclerotiorum virulence is affected by mycelial age via reduction in oxalate biosynthesis
    WANG Ji-peng, XU You-ping, ZANG Xian-peng, LI Shuang-sheng, CAI Xin-zhong
    2016, 15(05): 1034-1045.  DOI: 10.1016/S2095-3119(15)61199-6
    Abstract ( )   PDF in ScienceDirect  
    Sclerotinia sclerotiorum is one of the most devastating necrotrophic phytopathogens.  Virulence of the hyphae of this fungus at different ages varies significantly.  Molecular mechanisms underlying this functional distinction are largely unknown.  In this study, we confirmed the effect of mycelial culture time/age on virulence in two host plants and elucidated its molecular and morphological basis.  The virulence of the S. sclerotiorum mycelia in plants dramatically decreases along with the increase of the mycelial age.  Three-day-old mycelia lost the virulence in plants.  Comparative proteomics analyses revealed that metabolism pathways were comprehensively reprogrammed to suppress the oxalic acid (OA) accumulation in old mycelia.  The oxaloacetate acetylhydrolase (OAH), which catalyzes OA biosynthesis, was identified in the S. sclerotiorum genome.  Both gene expression and protein accumulation of OAH in old mycelia were strongly repressed.  Moreover, in planta OA accumulation was strikingly reduced in old mycelia-inoculated plants compared with young vegetative mycelia-inoculated plants.  Furthermore, supply with 10 mmol L–1 OA enabled the old mycelia infect the host plants, demonstrating that loss of virulence of old mycelia is mainly caused by being unable to accumulate OA.  Additionally, aerial mycelia started to develop from 0.5-day-old vegetative mycelia and dominated over 1-day-old mycelia grown on potato dextrose agar plates.  They were much smaller in hypha diameter and grew significantly slower than young vegetative mycelia when subcultured, which did not maintain to progenies.  Collectively, our results reveal that S. sclerotiorum aerial hyphae-dominant old mycelia fail to accumulate OA and thereby lose the virulence in host plants.
    Transgenic restorer rice line T1c-19 with stacked cry1C*/bar genes has low weediness potential without selection pressure
    HUANG Yao, LI Ji-kun, QIANG Sheng, DAI Wei-min, SONG Xiao-ling
    2016, 15(05): 1046-1058.  DOI: 10.1016/S2095-3119(15)61219-9
    Abstract ( )   PDF in ScienceDirect  
    Stacked (insect and herbicide resistant) transgenic rice T1c-19 with cry1C*/bar genes, its receptor rice Minghui 63 (herein MH63) and a local two-line hybrid indica rice Fengliangyou Xiang 1 (used as a control) were compared for agronomic performance under field conditions without the relevant selection pressures. Agronomic traits (plant height, tiller number, and aboveground dry biomass), reproductive ability (pollen viability, panicle length, and filled grain number of main panicles, seed set, and grain yield), and weediness characteristics (seed shattering, seed overwintering ability, and volunteer seedling recruitment) were used to assess the potential weediness without selection pressure of stacked transgene rice T1c-19. In wet direct-seeded and transplanted rice fields, T1c-19 and its receptor MH63 performed similarly regarding vegetative growth and reproductive ability, but both of them were significantly inferior to the control. T1c-19 did not display weed characteristics; it had weak overwintering ability, low seed shattering and failed to establish volunteers. Exogenous insect and herbicide resistance genes did not confer competitive advantage to transgenic rice T1c-19 grown in the field without the relevant selection pressures.
    cDNA cloning and characterization of the carboxylesterase pxCCE016b from the diamondback moth, Plutella xylostella L.
    HU Zhen-di, FENG Xia, LIN Qing-sheng, CHEN Huan-yu, LI Zhen-yu, YIN Fei, LIANG Pei, GAO Xi-wu
    2016, 15(05): 1059-1068.  DOI: 10.1016/S2095-3119(15)61278-3
    Abstract ( )   PDF in ScienceDirect  
        Carboxylesterase is a multifunctional superfamily and can be found in almost all living organisms. As the metabolic enzymes, carboxylesterases are involved in insecticides resistance in insects for long time. In our previous studies, the enhanced carboxylesterase activities were found in the chlorantraniliprole resistance strain of diamondback moth (DBM). However, the related enzyme gene of chlorantraniliprole resistance has not been clear in this strain. Here, a full-length cDNA of carboxylesterase pxCCE016b was cloned and exogenously expressed in Escherichia coli at the first time, which contained a 1 693 bp open reading frame (ORF) and encoded a protein of 542 amino acids. Sequence analysis showed that this cDNA has a predicted mass of 61.56 kDa and a theoretical isoelectric point value of 5.78. The sequence of deduced amino acid possessed the classical structural features: a type-B carboxylesterase signature 2 (EDCLYLNVYTK), a type-B carboxylesterase serine active site (FGGDPENITIFGESAG) and the catalytic triad (Ser186, Glu316, and His444). The real-time quantitative PCR (qPCR) analysis showed that the expression level of the pxCCE016b was significantly higher in the chlorantraniliprole resistant strain than in the susceptible strain. Furthermore, pxCCE016b was highly expressed in the midgut and epidermis of the DBM larvae. When the 3rd-instar larvae of resistant DBM were exposed to abamectin, alpha-cypermethrin, chlorantraniliprole, spinosad, chlorfenapyr and indoxacarb insecticides, the up-regulated expression of pxCCE016b was observed only in the group treated by chlorantraniliprole. In addition, recombinant vector pET-pxCCE016b was constructed with the most coding region (1 293 bp) and large number of soluble recombinant proteins (less than 48 kDa) were expressed successfully with prokaryotic cell. Western blot analysis showed that it was coded by pxCCE016b. All the above findings provide important information for further functional study, although we are uncertainty whether the pxCCE016b gene is actually involved in chlorantraniliprole resistance.
    Animal Science · Veterinary Science
    Genetic parameters and trends for production and reproduction traits of a Landrace herd in China
    ZHANG Zhe, ZHANG Hao, PAN Rong-yang, WU Long, LI Ya-lan, CHEN Zan-mou, CAI Geng-yuan, LI Jia-qi, WU Zhen-fang
    2016, 15(05): 1069-1075.  DOI: 10.1016/S2095-3119(15)61105-4
    Abstract ( )   PDF in ScienceDirect  
        The objectives of this study were to estimate the genetic parameters and the breeding progress in a Landrace herd in China, and to predict the potential benefits by applying new breeding technology. Hereby, the performance records from a Landrace swine herd in China, composing over 33 000 pigs born between 2001 and 2013, were collected on six economically important traits, i.e., average daily gain between 30–100 kg (ADG), adjusted backfat thickness at 100 kg (BF), adjusted days to 30 kg (D30), adjusted days to 100 kg (D100), number born alive (NBA), and total number born (TNB). The genetic parameters were estimated by restricted maximum likelihood via DMU, and realized genetic trends were analyzed. Based on the real population structure and genetic parameters obtained from this herd, the potential genetic trends by applying genomic selection (GS) were predicted via a computer simulation study. Results showed that the heritability estimates in this Landrace herd were 0.55 (0.02), 0.42 (0.01), and 0.12 (0.01), for BF, D100, and TNB, respectively. Favorable genetic trends were obtained for D100, BF, and TNB due to direct selection, for ADG and NBA due to indirect selection. Long-term selection against D100 did not improve D30, though they are highly genetically correlated (0.64). Appling GS in such a swine herd, the genetic gain can be increased by 25%, or even larger for traits with low heritability or individuals without phenotypes before selection. It can be concluded that conventional breeding strategy was effective in the herd studied, while applying GS is promising and hence the road ahead in swine breeding.
    Performance and plasma concentration of metabolites in transition dairy cows supplemented with vitamin E and fat
    Rohollah Amirifard, Mohammad Khorvash, Masiholla Forouzmand, Hamid-Reza Rahmani, Ahmad Riasi, Mohammad Malekkhahi, Mojtaba Yari, Morteza Hosseini-Ghaffari
    2016, 15(05): 1076-1084.  DOI: 10.1016/S2095-3119(15)61090-5
    Abstract ( )   PDF in ScienceDirect  
        The objective of this study was to evaluate the effects of vitamin E (VE; 1 500 or 3 000 international units (IU) d–1) and fat (2% of dry matter calcium salt of soybean oil) supplementation during the transition period on feed intake, milk yield and composition and blood metabolites of dairy cows.  48 multiparous Holstein cows were randomly assigned into one of four treatments in a 2×2 factorial arrangement of vitamin E and supplemental dietary fat during the transition period.  Treatments were: 1) 1 500 IU d–1 vitamin E without fat supplementation (1 500VE–F); 2) 1 500 IU d–1 vitamin E with fat supplement
    (1 500VE+F); 3) 3 000 IU d–1 vitamin E without fat supplementation (3 000VE–F); and 4) 3 000 IU d–1 vitamin E with fat supplement (3 000VE+F).  Dietary treatments were initiated at approximately 28 d before expected calving dates and continued through 28 d postpartum.  Dry matter intake (DMI) was unaffected (P>0.05) by prepartum treatment.  Regardless of vitamin E supplementation, DMI was greater (P<0.01) in fat-supplemented cows compared with un-supplemented cows (19.60 vs. 18.45 kg d–1; SEM=0.42) during the postpartum period.  Energy balance and body weight were not affected (P>0.05) by treatments.  Postpartum diets had no significant effect on milk yield or milk composition.  Plasma concentrations of non-esterified fatty acids, glucose, and insulin were not affected (P>0.05) by treatments.  Regardless of vitamin E supplementation, plasma β-hydroxybutyrate concentration was greater (P<0.05) in fat-supplemented cows compared with un-supplemented cows during the postpartum period.  These results showed no indication of positive effects on lactation performance associated with vitamin E and dietary fat supplement in transition cows.
    Differentiation of expression profiles of two calcineurin subunit genes in chicken skeletal muscles during early postnatal growth depending on anatomical location of muscles and breed
    SHAN Yan-ju, XU Wen-juan, SHU Jing-ting, ZHANG Ming, SONG Wei-tao, TAO Zhi-yun, ZHU Chunhong, LI Hui-fang
    2016, 15(05): 1085-1094.  DOI: 10.1016/S2095-3119(15)61162-5
    Abstract ( )   PDF in ScienceDirect  
      Calcineurin (Cn or CaN) is implicated in the control of skeletal muscle fiber phenotype and hypertrophy. However, little information is available concerning the expression of Cn in chickens. In the present study, the expression of two Cn subunit genes (CnAα and CnB1) was quantified by qPCR in the lateral gastrocnemius (LG, mainly composing of red fast-twitch myofibers), the soleus (mainly composing of red slow-twitch myofibers) and the extensor digitorum longus (EDL, mainly composing of white fast-twitch myofibers) from Qingyuan partridge chickens (QY, slow-growing chicken breed) and Recessive White chickens (RW, fast-growing chicken breed) on different days (1, 8, 22, 36, 50 and 64 days post-hatching). Although CnAα and CnB1 gene expressions were variable with different trends in different skeletal muscles in the two chicken breeds during postnatal growth, it is highly muscle phenotype and breed specific. In general, the levels of CnAα and CnB1 gene expressions of the soleus were lower than those of EDL and LG in both chicken breeds at the same stages. Compared between the two chicken breeds, the levels of CnAα gene expression of the three skeletal muscles in QY chickens were higher than those in RW chickens on days 1 and 22. However, on day 64, the levels of both CnAα and CnB1 gene expressions of the three skeletal muscles were lower in QY chickens than those in RW chickens. Correlation analysis of the levels of CnAα and CnB1 gene expressions of the same skeletal muscle showed that there were positive correlations for all three skeletal muscle tissues in two chicken breeds. These results provide some valuable clues to understand the role of Cn in the development of chicken skeletal muscles, with a function that may be related to meat quality.
    Nested RT-PCR method for the detection of European avian-like H1 swine influenza A virus
    WEI Yan-di, PEI Xing-yao, ZHANG Yuan, YU Chen-fang, SUN Hong-lei, LIU Jin-hua, PU Juan
    2016, 15(05): 1095-1102.  DOI: 10.1016/S2095-3119(15)61092-9
    Abstract ( )   PDF in ScienceDirect  
        Swine influenza A virus (swine IAV) circulates worldwide in pigs and poses a serious public health threat, as evidenced by the 2009 H1N1 influenza pandemic. Among multiple subtypes/lineages of swine influenza A viruses, European avian-like (EA) H1N1 swine IAV has been dominant since 2005 in China and caused infections in humans in 2010. Highly sensitive and specific methods of detection are required to differentiate EA H1N1 swine IAVs from viruses belonging to other lineages and subtypes. In this study, a nested reverse transcription (RT)-PCR assay was developed to detect EA H1 swine IAVs. Two primer sets (outer and inner) were designed specifically to target the viral hemagglutinin genes. Specific PCR products were obtained from all tested EA H1N1 swine IAV isolates, but not from other lineages of H1 swine IAVs, other subtypes of swine IAVs, or other infectious swine viruses. The sensitivity of the nested RT-PCR was improved to 1 plaque forming unit (PFU) mL–1 which was over 104 PFU mL–1 for a previously established multiplex RT-PCR method. The nested RT-PCR results obtained from screening 365 clinical samples were consistent with those obtained using conventional virus isolation methods combined with sequencing. Thus, the nested RT-PCR assay reported herein is more sensitive and suitable for the diagnosis of clinical infections and surveillance of EA H1 swine IAVs in pigs and humans.
    Development and evaluation of a herbal formulation with anti-pathogenic activities and probiotics stimulatory effects
    ZHOU Qian, WANG Si-si, YANG Guang, ZHAO Wen, LI Hui-ling
    2016, 15(05): 1103-1111.  DOI: 10.1016/S2095-3119(15)61146-7
    Abstract ( )   PDF in ScienceDirect  
       Searching alternative feed antibiotics is always a study hotspot in the field of animal production. In this study, the anti-pathogenic activities and probiotics stimulatory effects of 30 kinds of herbs were screened through Oxford cup method and Hungate roll method. 15 herbs showed significantly antibacterial activities (P<0.05) against Escherichia coli, Salmonella enteritidis, Salmonella typhimurium and Staphylococcus aureus. Seven herbs showed greatly stimulatory promoting effects on Lactobacillus acidophilus and Bifidobacterium longum. Finally, five herbs were combined for the developed formulation with selective antibacterial properties and they were Mume Fructus (35%), Isatidis Folium (25%), Moslae Herba (20%), Chrysanthemi Indici Flos (13%) and Bupleuri Radix (7%). The herbal formulation showed significantly antibacterial abilities against four pathogens and stimulatory promoting abilities on two probiotics in vitro and the equivalent activities in broiler chickens in vivo against E. coli and L. acidophilus. The toxicity study showed it had no toxicity, which indicated that it would be a kind of preferred candidate for an alternative antibiotic in future animal production.
    Soil & Fertilization﹒Irrigation﹒Plant Nutrition﹒ Agro-Ecology & Environment
    The inflence of soil drying- and tillage-induced penetration resistance on maize root growth in a clayey soil
    LIN Li-rong, HE Yang-bo, CHEN Jia-zhou
    2016, 15(05): 1112-1120.  DOI: 10.1016/S2095-3119(15)61204-7
    Abstract ( )   PDF in ScienceDirect  
        Soil drying may induce a number of stresses on crops. This paper investigated maize (Zea mays L.) root growth as affected by drought and soil penetration resistance (PR), which was caused by soil drying and tillage in a clayey red soil. Compared with conventional tillage (C) and deep tillage (D), soil compaction (P) and no-till (N) significantly increased soil PR in the 0–15 cm layer. The PR increased dramatically as the soil drying increased, particularly in soil with a high bulk density. Increased soil PR reduced the maize root mass density distribution not only in the vertical profile (0–20 cm) but also in the horizontal layer at the same distance (0–5, 5–10, 10–15 cm) from the maize plant. With an increase in soil PR in pots, the maize root length, root surface area and root volume significantly decreased. Specifically, the maize root length declined exponentially from 309 to 64 cm per plant with an increase in soil PR from 491 to 3 370 kPa; the roots almost stopped elongating when the soil PR was larger than 2 200 kPa. It appeared that fine roots (<2.5 mm in diameter) thickened when the soil PR increased, resulting in a larger average root diameter. The average root diameter increased linearly with soil PR, regardless of soil irrigation or drought. The results suggest that differences in soil PR caused by soil drying is most likely responsible for inconsistent root responses to water stress in different soils.
    Irrigation water salinity and N fertilization: Effects on ammonia oxidizer abundance, enzyme activity and cotton growth in a drip irrigated cotton fild
    MIN Wei, GUO Hui-juan, ZHANG Wen, ZHOU Guang-wei, MA Li-juan, YE Jun, HOU Zhen-an
    2016, 15(05): 1121-1131.  DOI: 10.1016/S2095-3119(15)61158-3
    Abstract ( )   PDF in ScienceDirect  
       Use of saline water in irrigated agriculture has become an important means for alleviating water scarcity in arid and semi-arid regions. The objective of this field experiment was to evaluate the effects of irrigation water salinity and N fertilization on soil physicochemical and biological properties related to nitrification and denitrification. A 3×2 factorial design was used with three levels of irrigation water salinity (0.35, 4.61 and 8.04 dS m–1) and two N rates (0 and 360 kg N ha–1). The results indicated that irrigation water salinity and N fertilization had significant effects on many soil physicochemical properties including water content, salinity, pH, NH4-N concentration, and NO3-N concentration. The abundance (i.e., gene copy number) of ammonia-oxidizing archaea (AOA) was greater than that of ammonia-oxidizing bacteria (AOB) in all treatments. Irrigation water salinity had no significant effect on the abundance of AOA or AOB in unfertilized plots. However, saline irrigation water (i.e., the 4.61 and 8.04 dS m–1 treatments) reduced AOA abundance, AOB abundance and potential nitrification rate in N fertilized plots. Regardless of N application rate, saline irrigation water increased urease activity but reduced the activities of both nitrate reductase and nitrite reductase. Irrigation with saline irrigation water significantly reduced cotton biomass, N uptake and yield. Nitrogen application exacerbated the negative effect of saline water. These results suggest that brackish water and saline water irrigation could significantly reduce both the abundance of ammonia oxidizers and potential nitrification rates. The AOA may play a more important role than AOB in nitrification in desert soil.
    Linking nutrient strategies with plant size along a grazing gradient: Evidence from Leymus chinensis in a natural pasture
    LI Xi-liang, LIU Zhi-ying, REN Wei-bo, DING Yong, JI Lei, GUO Feng-hui, HOU Xiang-yang
    2016, 15(05): 1132-1144.  DOI: 10.1016/S2095-3119(15)61171-6
    Abstract ( )   PDF in ScienceDirect  
        Studying the changes in nutrient use strategies induced by grazing can provide insight into the process of grassland degradation and is important for improving grassland quality and enhancing ecosystem function. Dominant species in meadow steppe can optimize their use of limiting resources; however, the regulation of nutrient use strategies across grazing gradients is not fully understood. Therefore, in this study, we report an in situ study in which the impact of grazing rates on nutrient use strategies of Leymus chinensis, the dominant plant species in eastern Eurasian temperate steppes, was investigated. We conducted a large randomized controlled experiment (conducted continuously for five years in grassland plots in a natural pasture in Hailar, eastern Mongolia Plateau, China) to assess the effects of grazing rate treatments (0.00, 0.23, 0.34, 0.46, 0.69, and 0.92 adult cattle unit (AU) ha–1) on L. chinensis along a grazing gradient and employed a random sampling approach to compare the accumulation, allocation, and stoichiometry of C, N, and P in leaves and stems. Our findings demonstrated the follows: (i) The height of L. chinensis decreased with an increase in the grazing gradient, and the concentrations of C, N, and P significantly increased; (ii) the accumulation of C, N, and P per individual was negatively correlated with the concentration of aboveground tissues, suggesting that there was a tradeoff in L. chinensis between nutrient accumulation and concentration at the individual scale; (iii) the leaf-to-stem ratio of C, N, and P accumulation increased with grazing intensity, indicating a tradeoff in nutrient allocation and plant size at the individual plant level; and (iv) grazing rates were negatively correlated with the ratios of C:N and C:P in the stem; however, these ratios in leaves significantly increased with grazing intensity. Our findings suggest that L. chinensis in meadow steppe adapts to grazing disturbance through tradeoffs between plant size and nutrient use strategies. Moreover, our results imply that grazing produces a compensatory effect on nutrient use efficiency between the stems and leaves of L. chinensis.
    Vegetation changes in the agricultural-pastoral areas of northern China from 2001 to 2013
    SU Wei, YU De-yong, SUN Zhong-ping, ZHAN Jun-ge, LIU Xiao-xuan, LUO Qian
    2016, 15(05): 1145-1156.  DOI: 10.1016/S2095-3119(15)61159-5
    Abstract ( )   PDF in ScienceDirect  
        Climate change and human activity have resulted in increasing change of vegetation growth globally. Numerous studies have been conducted on extreme climate events and analyses of ecological environment evolution. However, such studies have placed little emphasis on vegetation change and spatial variation in this type of ecotone. Accordingly, this study analyzed the changes in vegetation type and growth using the 16-d composite MOD13A1 product with 1-km resolution and MOD12Q1 product with 1-km resolution. We used the mean, maximum, standard deviation normalized-difference vegetation index (NDVI) values, and the rate of change (ROC) of NDVI value to explain vegetation changes within the studied ecotone. Our results showed that significant vegetation type and growth changes have occurred in the study area. From 2001 to 2013, for example, with the exception of 2001, 2004 and 2009, a certain extent of grassland area was converted to cropland. Drought severity index (DSI) results indicate that there exists drought in 2001, 2004 and 2009. Such temporal changes in cropland and grassland area confirmed the ecological vulnerability of the ecotone. At the same time, vegetation varied spatially from west to east and from south to north. The mean, maximum and standard deviation NDVI values were all sorted in descending order based on differences in latitude and longitude, as follows: NDVI2013>NDVI2009>NDVI2004>NDVI2001
    Food Science
    Differential volatile organic compounds in royal jelly associated with different nectar plants
    ZHAO Ya-zhou, LI Zhi-guo, TIAN Wen-li, FANG Xiao-ming, SU Song-kun, PENG Wen-jun
    2016, 15(05): 1157-1165.  DOI: 10.1016/S2095-3119(15)61274-6
    Abstract ( )   PDF in ScienceDirect  
        The aim of this work was to distinguish volatile organic compound (VOC) profiles of royal jelly (RJ) from different nectar plants.  Headspace solid-phase microextraction (HS-SPME) was used to extract VOCs from raw RJ harvested from 10 nectar plants in flowering seasons.  Qualitative and semi-quantitative analysis of VOCs extracts were performed by gas chromatography-mass spectrometry (GC-MS).  Results showed that VOC profiles of RJ from the samples were rich in acid, ester and aldehyde compound classes, however, contents of them were differential, exemplified by the data from acetic acid, benzoic acid methyl ester, hexanoic acid and octanoic acid.  As a conclusion, these four VOCs can be used for distinguishing RJ harvested in the seasons of different nectar plants.
    Fluorescent competitive assay for melamine using dummy molecularly imprinted polymers as antibody mimics
    DU Xin-wei, ZHANG Yan-xin, SHE Yong-xin, LIU Guang-yang, ZHAO Feng-nian, WANG Jing, WANG Shan-shan, JIN Fen, SHAO Hua, JIN Mao-jun, ZHENG Lu-fei
    2016, 15(05): 1166-1177.  DOI: 10.1016/S2095-3119(16)61357-6
    Abstract ( )   PDF in ScienceDirect  
        A fluorescent competitive assay for melamine was first developed utilizing dummy molecularly imprinted polymers (DMIPs) as artificial antibodies. This method is based on the competition between fluorescent substances and the unlabeled analyte for binding sites in synthesized DMIPs and the decreased binding of fluorescent substances to DMIPs due to increased concentrations of melamine in the solutions. DMIPs for melamine were synthesized under a hot water bath in the presence of the initiator azobisisobutyronitrile (AIBN) using 2,4-diamino-6-methyl-1,3,5-triazine (DAMT) as a dummy template, methacrylic acid (MAA) as a functional monomer, and ethylene glycol dimethacrylate (EGDMA) as a crosslinking agent. The adsorption capacity and selectivity of DMIPs for melamine were evaluated by the isothermal adsorption curve and Scatchard analysis. The evaluation results showed that the synthesized DMIPs had specific recognition sites for melamine and the maximum adsorption amount was 1 066.33 μg g–1. Later, 5-(4,6-dichlorotriazinyl) amino fluorescein (DTAF) with a triazine ring, which slightly resembles melamine, was selected as the fluorescent substance. The fluorescent competitive assay using DMIPs as the antibody mimics was finally established by selecting and optimizing the reaction solvents, DMIPs amount, DTAF concentration, and incubation time. The optimal detection system showed a linear response within range of 0.05–40 mg L–1 and the limit of detection (LOD) was 1.23 μg L–1. It was successfully applied to the detection of melamine in spiked milk samples with satisfactory recoveries (71.9 to 86.3%). According to the comparative analysis, the result of optimized fluorescent competitive assay revealed excellent agreement with the HPLC-MS/MS result for melamine.