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    Crop Genetics · Breeding · Germplasm Resources
    Advanced Backcross QTL Analysis for the Whole Plant Growth Duration Salt Tolerance in Rice (Oryza sativa L.)
    CHAILu1 , ZHANGJian1 , PANXiao-biao2 , ZHANGFan1 , ZHENGTian-qing1 , ZHAOXiu-qing1 , WANGWen-sheng1 , AliJauhar3 , XUJian-long1 , LIZhi-kang1
    2014, 13(8): 1609-1620.  DOI: 10.1016/S2095-3119(13)60575-4
    Abstract ( )   PDF in ScienceDirect  
    Salinity is a major factor limiting rice yield in coastal areas of Asia. To facilitate breeding salt tolerant rice varieties, the whole- plant growth duration salt tolerance (ST) was genetically dissected by phenotyping two sets of BC2F5 introgression lines (ILs) for four yield traits under severe natural salt stress and non-stress filed conditions using SSR markers and the methods of advanced backcross QTL (AB-QTL) analysis and selective introgression. Many QTLs affecting four yield traits under salt stress and non- stress conditions were identified, most (>90%) of which were clustered in 13 genomic regions of the rice genome and involved in complex epistasis. Most QTLs affecting yield traits were differentially expressed under salt stress and non-stress conditions. Our results suggested that genetics complementarily provides an adequate explanation for the hidden genetic diversity for ST observed in both IL populations. Some promising Huanghuazhan (HHZ) ILs with favorable donor alleles at multiple QTLs and significantly improved yield traits under salt stress and non-stress conditions were identified, providing excellent materials and relevant genetic information for improving rice ST by marker-assisted selection (MAS) or genome selection.
    Expression Pattern Analysis of Zinc Finger Protein Genes in Wheat (Triticum aestivum L.) Under Phosphorus Deprivation
    LIXiao-juan2 , GUOCheng-jin1 , LUWen-jing2 , DUANWei-wei1 , ZHAOMiao3 , MAChun-ying1 , GUJun-tao2 , XIAOKai1
    2014, 13(8): 1621-1633.  DOI: 10.1016/S2095-3119(13)60739-X
    Abstract ( )   PDF in ScienceDirect  
    Zinc finger protein (ZFP) genes comprise a large and diverse gene family, and are involved in biotic and abiotic stress responses in plants. In this study, a total of 126 ZFP genes classified into various types in wheat were characterized and subjected to expression pattern analysis under inorganic phosphate (Pi) deprivation. The wheat ZFP genes and their corresponding GenBank numbers were obtained from the information of a 4×44K wheat gene expression microarray chip. They were confirmed by sequence similarity analysis and named based on their homologs in Brachypodium distachyon or Oriza sativa. Expression analysis based on the microarray chip revealed that these ZFP genes are categorized into 11 classes according to their gene expression patterns in a 24-h of Pi deprivation regime. Among them, ten genes were differentially up-regulated, ten genes differentially down- regulated, and two genes both differentially up- and down-regulated by Pi deprivation. The differentially up- or down-regulated genes exhibited significantly more or less transcripts at one, two, or all of the checking time points (1, 6, and 24 h) of Pi stress in comparison with those of normal growth, respectively. The both differentially up- and down-regulated genes exhibited contrasting expression patterns, of these, TaWRKY70;5 showed significantly up-regulated at 1 and 6 h and down-regulated at 24 h whereas TaAN1AN20-8;2 displayed significantly upregulated at 1 h and downregulated at 6 h under deprivation Pi condition. Real time PCR analysis confirmed the expression patterns of the differentially expressed genes obtained by the microarray chip. Our results indicate that numerous ZFP genes in wheat respond to Pi deprivation and have provided further insight into the molecular basis that plants respond to Pi deprivation mediated by the ZFP gene family.
    Arabidopsis Phytochrome D Is Involved in Red Light-Induced Negative Gravitropism of Hypocotyles
    LIJian-ping , HOUPei , ZHENGXu , SONGMei-fang , SULiang , YANGJian-ping
    2014, 13(8): 1634-1639.  DOI: 10.1016/S2095-3119(13)60607-3
    Abstract ( )   PDF in ScienceDirect  
    The phytochrome gene family, which is in Arabidopsis thaliana, consists of phytochromes A-E (phyA to phyE), regulates plant responses to ambient light environments. PhyA and phyB have been characterized in detail, but studies on phyC to phyE have reported discrepant functions. In this study, we show that phyD regulates the Arabidopsis gravitropic response by inhibiting negative gravitropism of hypocotyls under red light condition. PhyD had only a limited effect on the gravitropic response of roots in red light condition. PhyD also enhanced phyB-regulated gravitropic responses in hypocotyls. Moreover, the regulation of hypocotyl gravitropic responses by phyD was dependent upon the red light fluence rate.
    Recent Advances in the Role of the Elongator Complex in Plant Physiology and tRNA Modification: A Review
    YAN Xu, JIN Xiao-huan, WANG You-mei, ZHENG Bo , CHEN Peng
    2014, 13(8): 1640-1650.  DOI: 10.1016/S2095-3119(13)60524-9
    Abstract ( )   PDF in ScienceDirect  
    The Elongator complex is a multifunction protein complex which has been shown to be involved in transcriptional elongation, DNA replication and repair, tubulin and histone acetylation, gene silencing and tranfer RNA uridine modification. The composition of the Elongator complex is found to be highly conserved in eukaryotes, protein homologs of various subunits have been identified in fungi, plant, animal, and human. Remarkably, mutation in genes encoding the Elongator complex structural components all results in defects of transfer RNA wobble uridine modification, and this function of the Elongator complex is also conserved in eukaryotes. The Elongator complex mutants in higher plants have pleiotropic phenotypes including defects in vegetative growth, abiscisic acid hypersensitivity, elevated tolerance to drought and oxidative stress. What is the relationship between the Elongator complex’s function in nucleoside modification and its activity in other cellular pathways? This review summarizes the recent advances in study of function of the Elongator complex, in the aspects of cell physiology and molecular biology.
    Cloning and Characterization of a Salt Tolerance-Associated Gene Encoding Trehalose-6-Phosphate Synthase in Sweetpotato
    JIANG Tao, ZHAI Hong, WANG Fei-bing, ZHOU Hua-nan, SI Zeng-zhi, HE Shao-zhen , LIU Qing-chang
    2014, 13(8): 1651-1661.  DOI: 10.1016/S2095-3119(13)60534-1
    Abstract ( )   PDF in ScienceDirect  
    Trehalose plays an important role in metabolic regulation and abiotic stress tolerance in a variety of organisms. In plants, its biosynthesis is catalyzed by two key enzymes: trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP). In the present study, a TPS gene, named IbTPS, was first isolated from sweetpotato (Ipomoea batatas (L.) Lam.) cv. Lushu 3 by rapid amplification of cDNA ends (RACE). The open reading frame (ORF) contained 2 580 nucleotides encoding 859 amino acids with a molecular weight of 97.433 kDa and an isoelectric point (pI) of 5.7. The deduced amino acid sequence showed high identities with TPS of other plants. Real-time quantitative PCR analysis revealed that the expression level of IbTPS gene was significantly higher in stems of Lushu 3 than in its leaves and roots. Subcellular localization analysis in onion epidermal cells indicated that IbTPS gene was located in the nucleus. Transgenic tobacco (cv. Wisconsin 38) plants over-expressing IbTPS gene exhibited significantly higher salt tolerance compared with the control plant. Trehalose and proline content was found to be significantly more accumulated in transgenic tobacco plants than in the wild-type and several stress tolerance related genes were up-regulated. These results suggest that IbTPS gene may enhance salt tolerance of plants by increasing the amount of treahalose and proline and regulating the expression of stress tolerance related genes.
    NBS Profiling Identifies Potential Novel Locus from Solanum demissum That Confers Broad-Spectrum Resistance to Phytophthora infestans
    ZHANG Kun, XU Jian-fei, DUAN Shao-guang, PANG Wan-fu, BIAN Chun-song, LIU Jie and JIN
    2014, 13(8): 1662-1671.  DOI: 10.1016/S2095-3119(14)60759-0
    Abstract ( )   PDF in ScienceDirect  
    Potato late blight, caused by the oomycete pathogen Phytophthora infestans, is the most serious disease of potato worldwide. The adoption of varieties with resistance genes, especially broad-spectrum resistance genes, is the most efficient approach to control late blight. Solanum demissum is a well-known wild potato species from which 11 race-specific resistance genes have been identified, however, no broad-spectrum resistance genes like RB have been reported in this species. Here, we report a novel reisistance locus from S. demissum that potentially confer broad-spectrum resistance to late blight. A small segregating population of S. demissum were assessed for resistance to aggressive P. infestans isolates (race 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11). This coupled with nucleotide binding site (NBS) profiling analyses, led to the identification of three fragments that linked to the potential candidate resistance gene(s). Cloning and sequence analysis of these fragments suggested that the identified resistance gene locus is located in the region containing R2 resistance gene at chromosome 4. Based on the sequences of the cloned fragments, a co-segregating sequence characterized amplified region (SCAR) marker, RDSP, was developed. The newly identified marker RDSP will be useful for marker assisted breeding and further cloning of this potential resistance gene locus.
    Analysis of Variations in White-Belly and White-Core Rice Kernels Within a Panicle and the Effect of Panicle Type
    ZHANG Xin-cheng, Md A. Alim, LIN Zhao-miao, LIU Zheng-hui, LI Gang-hua, WANG Qiang-sheng
    2014, 13(8): 1672-1679.  DOI: 10.1016/S2095-3119(13)60593-6
    Abstract ( )   PDF in ScienceDirect  
    This study aims to investigate the variation in occurrence of white-belly rice kernel (WBRK) and white-core rice kernel (WCRK) among different positions within a panicle. Twenty-four M4 mutants involved in four panicle types, namely the compact, intermediate, loose, and chicken foot panicle were used. They derived from a japonica rice cultivar Wuyujing 3. Considerable differences in morphological characters existed among the four types of panicle, especially in panicle length, the secondary branch number and ratio of grain number to total branch length. Marked differences were found in WBRK and WCRK among different positions within a panicle for all types of panicle. In general, grains located on the primary rachis and top rachis branches had higher WBRK and WCRK percentage than those on the secondary rachis and bottom rachis branches. WCRK exhibited larger variation among grain positions than WBRK did. Moreover, there was a significant difference in WCRK/WBRK among grain positions within a panicle, with primary rachis and top rachis branches having higher values than the secondary and bottom rachis. In addition, panicle type showed no significant effect on the pattern of WBRK and WCRK occurrence within a panicle. The results indicated the difference in mechanism of WBRK and WCRK formation in grain position within a panicle, and are valuable for breeding and agronomic practices aimed at lowering chalky grain rate.
    Effect of Source-Sink Manipulation on Photosynthetic Characteristics of Flag Leaf and the Remobilization of Dry Mass and Nitrogen in Vegetative Organs of Wheat
    ZHANG Ying-hua, SUN Na-na, HONG Jia-pei, ZHANG Qi, WANG Chao, XUE Qing-wu, ZHOU Shun-li, HUANG Qin , WANG Zhi-min
    2014, 13(8): 1680-1690.  DOI: 10.1016/S2095-3119(13)60665-6
    Abstract ( )   PDF in ScienceDirect  
    The photosynthetic characteristics of flag leaf and the accumulation and remobilization of pre-anthesis dry mass (DM) and nitrogen (N) in vegetable organs in nine wheat cultivars under different source-sink manipulation treatments including defoliation (DF), spike shading (SS) and half spikelets removal (SR) were investigated. Results showed that the SS treatment increased the photosynthetic rate (Pn) of flag leaf in source limited cultivar, but had no significant effect on sink limited cultivar. The SR treatment decreased the Pn of flag leaf. Grain DM accumulation was limited by source in some cultivars, in other cultivars, it was limited by sink. Grain N accumulation was mainly limited by source supply. The contribution of pre-anthesis dry mass to grain yield from high to low was stem, leaf and chaff, while the contribution of pre-anthesis N to grain N from high to low was leaf, stem and chaff. Cultivars S7221 and TA9818 can increase the contribution of remobilization of DM and N to grain at the maximum ratio under reducing source treatments, which may be the major reason for these cultivars having lower decrease in grain yield and N content under reducing source treatments.
    Evaluation of Essential and Toxic Element Concentrations in Buckwheat by Experimental and Chemometric Approaches
    PENG Lian-xin, HUANG Yan-fei, LIU Yuan, ZHANG Zhi-feng, LU Lu-yang , ZHAO Gang
    2014, 13(8): 1691-1698.  DOI: 10.1016/S2095-3119(13)60724-8
    Abstract ( )   PDF in ScienceDirect  
    The essential and toxic element concentrations in buckwheat were analyzed by inductively coupled plasma optical emission spectrometer (ICP-OES). The concentration data were subjected to common chemometrics analyses, including correlation analysis (CA), principal component analysis (PCA) and hierarchical cluster analysis (HCA), to gain better understanding of the differences among the tested samples. Our results indicated that the essential and toxic element concentrations were not different between Fagopyrum tataricum (L.) Gaertn and F. esculentum Moench. The element concentrations varied among buckwheat samples from different sources. Commercial tartary buckwheat tea contained several essential elements, thus, could be used as the source of essential elements. The detection of toxic heavy metals in commercial tartary buckwheat tea suggested that safety issue of such buckwheat products should be seriously concerned. Our results also revealed that the place of origin and the processing protocol of tartary buckwheat affected the element concentrations of the commercial form. The implications to the quality control and safety evaluation of buckwheat were extensively discussed.
    Replanting Affects the Tree Growth and Fruit Quality of Gala Apple
    LIU En-tai, WANG Gong-shuai, LI Yuan-yuan, SHEN Xiang, CHEN Xue-sen, SONG Fu-hai, WU Shu-jing, CHEN Qiang, MAO Zhi-quan
    2014, 13(8): 1699-1706.  DOI: 10.1016/S2095-3119(13)60620-6
    Abstract ( )   PDF in ScienceDirect  
    Apple replant disease (ARD) causes the inhibition of root system development, stunts tree growth and so on. To further investigate the effects of ARD on apple fruits, a 25-year-old apple orchard was remediated to establish a replant orchard between November 2008 and March 2009. A rotational cropping orchard was established on an adjacent wheat field. The cultivar and rootstock-scion combination used in the newly established orchards was Royal Gala/M26/Malus hupehensis Rehd. Ripe fruits were collected in mid-August 2011 and mid-August 2012, meanwhile, the following indices were measured: yield per plant; fruit weight; the fruit shape index; the contents of anthocyanin, carotenoid and chlorophyll; the soluble sugar content in the flesh; titratable acid; the sugar-acid ratio; firmness; and aroma components; apple plant ground diameter, plant height increment and the total length of the current-year shoots. The results showed that compared to rotational cropping, continuous cropping yielded statistically significant reductions in fruit weight and yield per plant of 39.8 and 76.5%, respectively. However, there were no changes in the fruit shape index. The anthocyanin and carotenoid contents decreased by 81.7 and 37.7%, respectively, while the chlorophyll content increased by 251.0%. All of these differences in content were statistically significant. The soluble sugar levels and sugar-acid ratio decreased by 25.4 and 60.9%, respectively, but the titratable acid levels and fruit firmness increased by 90.9 and 42.8%, respectively. Ten of the most important esters contributing to the apple aroma were analyzed, and the following changes were observed: hexyl acetate, butyl acetate, hexyl butyrate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, butyl butyrate, 2-methyl-butyl butyrate, hexyl propionate and hexyl hexanoate decreased by 25.5, 78.4, 89.1, 55.5, 79.5, 77.2, 86.8, 69.9, 61.2, and 68.1%, respectively. The contents of three other aroma components, (E)-2-hexenal, hexanal and 1-hexanol, significantly increased. Eight characteristic aroma components were found in the rotational cropping fruits: hexyl acetate, butyl acetate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, 2-methyl- butyl butyrate, hexyl acetate and hexyl propionate. There were four characteristic ester components (hexyl acetate, butyl acetate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate) and two characteristic aldehyde aroma components ((E)-2-hexenal and hexanal) in the continuous cropping fruits. Compared with the rotational cropping fruits, four characteristic ester components were declined and two characteristic aldehyde aroma components were increased. Compared with the control, replanted apple plant ground diameter, plant height increment and the total length of the current-year shoots were reduced by 27.6, 40.6 and 72.2%, respectively.
    Plant Protection
    A New Disease of Cherry Plum Tree with Yellow Leaf Symptoms Associated with a Novel Phytoplasma in the Aster Yellows Group
    LI Zheng-nan, ZHANG Lei, TAO Ye, CHI Ming, XIANG Yu , WU Yun-feng
    2014, 13(8): 1707-1718.  DOI: 10.1016/S2095-3119(13)60600-0
    Abstract ( )   PDF in ScienceDirect  
    A novel phytoplasma was detected in a cherry plum (Prunus cerasifera Ehrh) tree that mainly showed yellow leaf symptom. The tree was growing in an orchard located in Yangling District, Shaanxi Province, China. The leaves started as chlorotic and yellowing along leaf minor veins and leaf tips. Chlorosis rapidly developed to inter-veinal areas with the whole leaf becoming pale yellow in about 1-4 wk. Large numbers of phytoplasma-like bodies (PLBs) were seen under transmission electron microscopy. The majority of the PLBs was spherical or elliptical vesicles, with diameters in range of 0.1-0.6 μm, and distributed in the phloem cells of the infected tissues. A 1246-bp 16S ribosomal RNA (rRNA) gene fragment was amplified from DNA samples extracted from the yellow leaf tissues using two phytoplasma universal primer pairs R16mF2/R16mR1 and R16F2n/R16R2. Phylogenetic analysis using the 16S rRNA gene sequence suggested that the phytoplasma associated with the yellow leaf symptoms belongs to a novel subclade in the aster yellows (AY) group (16SrI group). Virtual and actual restriction fragment length polymorphism (RFLP) analysis of the 16S rRNA gene fragment revealed that the phytoplasma was distinguishable from all existing 19 subgroups in the AY group (16SrI) by four restriction sites, Hinf I, Mse I, Sau3A I and Taq I. The similarity coefficients of comparing the RFLP pattern of the 16S rRNA gene fragment of this phytoplasma to each of the 19 reported subgroups ranged from 0.73 to 0.87, which indicates the phytoplasma associated with the cherry plum yellow leaf (CPYL) symptoms is probably a distinct and novel subgroup lineage in the AY group (16SrI). In addition, the novel phytoplasma was experimentally transmitted to periwinkle (Catharanthus roseus) plants from the tree with CPYL symptoms and then back to a healthy 1-yr-old cherry plum tree via dodder (Cuscuta odorata) connections.
    Isolation, Identification, and Herbicidal Activity of Metabolites Produced by Pseudomonas aeruginosa CB-4
    YANG Juan, CAO Hong-zhe, WANG Wei, ZHANG Li-hui , DONG Jin-gao
    2014, 13(8): 1719-1726.  DOI: 10.1016/S2095-3119(13)60695-4
    Abstract ( )   PDF in ScienceDirect  
    CB-4, a bacterial strain with highly effective herbicidal activity, was isolated from infected corn leaves. Through morphology, physiological and biochemical tests, and 16S ribosomal DNA gene sequencing methods, CB-4 was identified as Pseudomonas aeruginosa. We conducted activity-evaluation experiments in the laboratory to assess the herbicidal potential of metabolites produced by strain CB-4. Crude extracts of strain CB-4 have high inhibition activity on Digitaria sanguinalis. In general, the root and shoot growth parameters of D. sanguinalis were significantly reduced by metabolites of strain CB-4. The IC50 of the culture filtrate extracts for the radicula and coleoptile of D. sanguinalis were 0.299 and 0.210 mg mL-1, respectively. Component 2 of the herbicidal activity of the crude toxin from strain CB-4 was successfully purified for the first time by using high-speed counter current chromatography with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water (4:5:4:5, v/v) and high-performance liquid chromatography. We concluded that the metabolites of strain CB-4 have the potential to be developed as a microbe-based herbicide.
    Performance of Three Adelphocoris spp. (Hemiptera: Miridae) on Flowering and Non-flowering Cotton and Alfalfa
    GAO Zhen, PAN Hong-sheng, LIU Bing, LU Yan-hui and LIANG Ge-mei
    2014, 13(8): 1727-1735.  DOI: 10.1016/S2095-3119(13)60592-4
    Abstract ( )   PDF in ScienceDirect  
    The genus Adelphocoris (Hemiptera: Miridae) is a group of key insect pests in cotton fields in China that includes three dominant species: A. suturalis (Jakovlev), A. lineolatus (Goeze) and A. fasciaticollis (Reuter). Previous field surveys have found that adults of these Adelphocoris species usually move onto specific host plants when the plants enter the flowering stage. To determine the potential trade-offs for this host-plant preference behavior, the performance of these three Adelphocoris spp. on flowering and non-flowering cotton and alfalfa were compared in the laboratory. The results showed that Adelphocoris spp. had significantly higher nymphal developmental and survival rates, along with increased adult longevity and fecundity on flowering cotton and alfalfa than on non-flowering plants of either species. In addition, compared with cotton plants, alfalfa generally promoted better performance of these three Adelphocoris species, especially for A. lineolatus. Simple correlation analysis indicated that female adult longevity was positively correlated to male adult longevity and female fecundity, and female fecundity was positively correlated to nymphal development and survival rates. This study demonstrated a positive correlation between adult preference and offspring/adult performance for all three Adelphocoris species, with no evidence of any trade-offs for this preference for flowering host plants. These findings support the hypothesis that hemimetabolous insects such as mirid bugs have positive adult preference-adult/nymphal performance relationships, which is likely due to the similar feeding habits and nutritional requirements of adults and nymphs.
    Automated Counting of Rice Planthoppers in Paddy Fields Based on Image Processing
    YAO Qing, XIAN Ding-xiang, LIU Qing-jie, YANG Bao-jun, DIAO Guang-qiang , TANG Jian
    2014, 13(8): 1736-1745.  DOI: 10.1016/S2095-3119(14)60799-1
    Abstract ( )   PDF in ScienceDirect  
    A quantitative survey of rice planthoppers in paddy fields is important to assess the population density and make forecasting decisions. Manual rice planthopper survey methods in paddy fields are time-consuming, fatiguing and tedious. This paper describes a handheld device for easily capturing planthopper images on rice stems and an automatic method for counting rice planthoppers based on image processing. The handheld device consists of a digital camera with WiFi, a smartphone and an extrendable pole. The surveyor can use the smartphone to control the camera, which is fixed on the front of the pole by WiFi, and to photograph planthoppers on rice stems. For the counting of planthoppers on rice stems, we adopt three layers of detection that involve the following: (a) the first layer of detection is an AdaBoost classifier based on Haar features; (b) the second layer of detection is a support vector machine (SVM) classifier based on histogram of oriented gradient (HOG) features; (c) the third layer of detection is the threshold judgment of the three features. We use this method to detect and count whiteback planthoppers (Sogatella furcifera) on rice plant images and achieve an 85.2% detection rate and a 9.6% false detection rate. The method is easy, rapid and accurate for the assessment of the population density of rice planthoppers in paddy fields.
    Animal Science · Veterinary Science
    Effect of Graded Levels of Fiber from Alfalfa Meal on Nutrient Digestibility and Flow of Fattening Pigs
    CHEN Liang, GAO Li-xiang , ZHANG Hong-fu
    2014, 13(8): 1746-1752.  DOI: 10.1016/S2095-3119(13)60571-7
    Abstract ( )   PDF in ScienceDirect  
    The fiber level and composition have an important effect on nutrient digestibility of swine diets. Little information is known about the effects of fiber level and composition from alfalfa meal on nutrient digestibility of fattening pigs fed a corn-soybean meal-based diet. The objective of this experiment was to determine the effects of alfalfa fiber on the growth performance, intestinal nutrient flow and apparent total tract digestibility (ATTD) of nutrients in fattening pigs. 24 barrows (Duroc×(Large White×Landrace), body weight=(60.6±0.7) kg) were randomly allotted to 4 treatments with 6 replicates of 1 pig per replicate. The pigs were provided a control diet or a diet containing 5, 10 or 20% of alfalfa meal during a 14-d experiment period. Average daily gain (ADG) and the ATTD of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and gross energy (GE) reduced linearly as the level of alfalfa meal in the diet increased (P<0.01). The total tract flow of DM, OM, CP, NDF, ADF, and GE increased with the increase in dietary alfalfa (linear, P<0.05). Growth performance and nutrient digestion were not affected by inclusion of 5% alfalfa meal in the diet (P>0.05). A multiple linear regression analysis, taking into account both soluble and insoluble fiber intake, explained approximately 70% of the variation in the ATTD of DM, OM, NDF, and GE (P<0.01). In conclusion, alfalfa meal should be limited to less than 5% of the diet in fattening pigs to maximize growth performance and nutrient digestion. Soluble and insoluble fiber from alfalfa meal has the differential roles in nutrient digestion, which may help explain the main variation observed in nutrient digestibility. These findings suggest that knowledge of specific fiber components is necessary to accurately predict the effects of dietary fiber on nutrient digestibility.
    Replacement of Forage Fiber Sources with Dried Distillers Grains with Solubles and Corn Germ Meal in Holstein Calf Diets
    XU Jun, HOU Yu-jie, ZHAO Guo-qi, YU Ai-bing, SU Yan-jing, HUO Yong-jiu , ZHU Jianming
    2014, 13(8): 1753-1758.  DOI: 10.1016/S2095-3119(13)60602-4
    Abstract ( )   PDF in ScienceDirect  
    This study was carried out to determine the effect of replacement of forage fiber sources from alfalfa and Leymus chinensis with nonforage fiber sources (NFFS) from dried distillers grains with solubles and corn germ meal on calves growth, rumen development and blood parameters. 48 female and 12 male calves ((110.55±15.36) kg of body weight and 12 wk of age) were assigned randomly to four dietary treatments (15 calves/treatment) in a completely randomized design. Experimental diets were: 0% NFFS (control), 9% NFFS (group 1), 18% NFFS (group 2), 27% NFFS (group 3), and contained equivalent neutral detergent fiber and total digestible nutrients, respectively. The dry matter intake was similar among diets, averaging 3.33 kg d-1, and no differences were detected for body weight, withers height, body length and heart girth. In addition, the development of rumen, reticulum, omasum and abomasum also were similar among diets. Dry matter, crude protein, and neutral detergent fiber digestibilities increased with the increasing levels of NFFS in the experimental diets, but had no significant effect. Blood urea nitrogen, total protein and glubulin were not affected by the dietary treatment, but group 3 resulted in the highest (P<0.05) concentrations of glucose and the lowest (P<0.05) concentrations of triglycerides and albumin. In conclusion, dried distillers grains with solubles (DDGS) and corn germ meal (CGM) were available and alternative fiber sources for Holstein calf diets.
    CDH1, a Novel Surface Marker of Spermatogonial Stem Cells in Sheep Testis
    ZHANG Yan, WU Sachula, LUO Fen-hua, Baiyinbatu , LIU Lin-hong, HU Tian-yuan, YU Bo-yang, LI Guang-peng , WU Ying-ji
    2014, 13(8): 1759-1765.  DOI: 10.1016/S2095-3119(13)60689-9
    Abstract ( )   PDF in ScienceDirect  
    Spermatogonial stem cells (SSCs) are unique stem cells in adult body that can transmit genetic information to the next generation. They have self-renewal potential and can continuously support spermatogenesis throughout life of a male animal. However, the SSC population is extremely small, isolation and purification of the SSCs is challenging, especially for livestock animals. It has been confirmed that CDH1 (cadherin-1, also known as E-cadherin) can be expressed in undifferentiated SSCs of mouse and rats, but it has not been verified in sheep. Here, CDH1 was found as a novel surface marker for sheep SSCs. In this paper, sheep anti- CDH1 polyclonal antibodies were prepared and its activity was checked. Using the obtained antibodies and immunohistochemistry analysis, we confirmed that CDH1 can be expressed by SSCs in sheep testis.
    The Midgut Bacterial Flora of Laboratory-Reared Hard Ticks, Haemaphysalis longicornis, Hyalomma asiaticum, and Rhipicephalus haemaphysaloides
    LI Chun-hong, CAO Jie, ZHOU Yong-zhi, ZHANG Hou-shuang, GONG Hai-yan , ZHOU Jin-lin
    2014, 13(8): 1766-1771.  DOI: 10.1016/S2095-3119(13)60517-1
    Abstract ( )   PDF in ScienceDirect  
    Ixodid ticks play an important role in the transmission of a variety of zoonoses of viral, bacterial and protozoan origin, and they also harbor a wealth of microorganisms. To gain more detailed insights into the potential interactions between bacterial flora and tick-borne pathogens, we investigated the midgut bacterial flora of laboratory-reared Haemaphysalis longicornis, Hyalomma asiaticum and Rhipicephalus haemaphysaloides. Based on morphological, biochemical, and 16S rDNA sequencing results, we identified 15 species belonging to 12 genera in the midgut of the three ticks. The bacterial communities were similar to those found in other studies of hematophagous arthropods. Kocuria sp. was the most frequently isolated species and its 16S rDNA gene sequence was very similar to Kocuria koreensis P31T. To our knowledge, this is the first report of the bacterial flora of tick midguts and the results show that there were many different bacterial species in each tick species. Among the most common genera, there may have been a novel species in the genus Kocuria. The results might be the first step for looking for different aspects of the pathogen and tick interaction.
    Soil & Fertilization · Irrigation · Agro-Ecology & Environment
    Effects of Long-Term Winter Planted Green Manure on Distribution and Storage of Organic Carbon and Nitrogen in Water-Stable Aggregates of Reddish Paddy Soil Under a Double-Rice Cropping System
    YANG Zeng-ping, ZHENG Sheng-xian, NIE Jun, LIAO Yu-lin, XIE Jian
    2014, 13(8): 1772-1781.  DOI: 10.1016/S2095-3119(13)60565-1
    Abstract ( )   PDF in ScienceDirect  
    In agricultural systems, maintenance of soil organic matter has long been recognized as a strategy to reduce soil degradation. Manure amendments and green manures are management practices that can increase some nutrient contents and improve soil aggregation. We investigated the effects of 28 yr of winter planted green manure on soil aggregate-size distribution and aggregateassociated carbon (C) and nitrogen (N). The study was a randomized completed block design with three replicates. The treatments included rice-rice-fallow, rice-rice-rape, rice-rice-Chinese milk vetch and rice-rice-ryegrass. The experiment was established in 1982 on a silty light clayey paddy soil derived from Quaternary red clay (classified as Fe-Accumuli-Stagnic Anthrosols) with continuous early and late rice. In 2009, soil samples were collected (0-15 cm depth) from the field treatment plots and separated into water-stable aggregates of different sizes (i.e., >5, 2-5, 1-2, 0.5-1, 0.25-0.5 and <0.25 mm) by wet sieving. The long-term winter planted green manure significantly increased total C and N, and the formation of the 2-5-mm water-stable aggregate fraction. Compared with rice-rice-rape, rice-rice-Chinese milk vetch and rice-rice-ryegrass, the rice-rice-fallow significantly reduced 2-5-mm water-stable aggregates, with a significant redistribution of aggregates into micro-aggregates. Long-term winter planted green manure obviously improved C/N ratio and macro-aggregate-associated C and N. The highest contribution to soil fertility was from macro-aggregates of 2-5 mm in most cases.
    The Effects of Farmyard Manure and Mulch on Soil Physical Properties in a Reclaimed Coastal Tidal Flat Salt-Affected Soil
    ZHANG Jian-bing, YANG Jing-song, YAO Rong-jiang, YU Shi-peng, LI Fu-rong , HOU Xiao-jing
    2014, 13(8): 1782-1790.  DOI: 10.1016/S2095-3119(13)60530-4
    Abstract ( )   PDF in ScienceDirect  
    Careful soil management is important for the soil quality and productivity improvement of the reclaimed coastal tidal flat saline land in northern Jiangsu Province, China. Farmyard manure (FYM) and mulch applications, which affect soil characteristics and plant significantly, are regard as an effective pattern of saline land improvement. As a conventional management in the study region, FYM and mulch are used for the amendment of the new reclaimed tidal flat regularly, but little is known about their effects on soil physical properties functioning. A study was conducted on a typical coastal tidal flat saline land, which was reclaimed in 2005, to evaluate the effects of FYM, polyethylene film mulch (PM), straw mulch (SM), FYM combined with PM (FYM+PM), FYM combined with SM (FYM+SM), on soil hydraulic properties and soil mechanical impedance. CK represented conventional cultivation in study area without FYM and mulch application and served as a control. The experiment, laid out in a randomized complete block design with three replications, was studied in Huanghaiyuan Farm, which specialized in the agricultural utilization for coastal tidal flat. Result showed that capillary water holding capacity (CHC), saturated water content (SWC), saturated hydraulic conductivity (Ks) and bulk density (BD), cone index (CI) were affected significantly by the FYM and mulch application, especially in the 0-10 cm soil layer. FYM and mulch management increased CHC, SWC and Ks over all soil depth in the order of FYM+SM>FYM+PM>FYM>SM>PM>CK. With the contrary sequence, BD and CI decreased significantly; however, FYM and mulch application affected BD and CI only in the upper soil layers. CHC, SWC and Ks decreased significantly with the increasing of soil depth, BD and CI, and a significant liner equation was found between CHC, SWC, Ks and BD, CI. With the highest CHC (38.15%), SWC (39.55%), Ks (6.00 mm h-1) and the lowest BD (1.26 g cm-3) and CI (2.71 MPa), the combined management of FYM and SM was recommend to be an effective method for the melioration of reclaimed coastal tidal flat saline soil.
    Monitoring Perennial Sub-Surface Waterlogged Croplands Based on MODIS in Jianghan Plain, Middle Reaches of the Yangtze River
    XIAO Fei, LI Yuan-zheng, DU Yun, LING Feng, YAN Yi, FENG Qi , BAN Xuan
    2014, 13(8): 1791-1801.  DOI: 10.1016/S2095-3119(13)60563-8
    Abstract ( )   PDF in ScienceDirect  
    Perennial waterlogged soil (PWS) is induced by the high level of groundwater, and has a persistent impact on natural ecosystems and agricultural production. Traditionally, distribution information regarding PWS is mainly collected from in situ measurements through groundwater level surveys and physicochemical property analyses. However, in situ measurements of PWS are costly and time-consuming, only rough estimates of PWS areas are available in some regions. In this paper, we developed a method to monitor the perennial waterlogged cropland using time-series moderate resolution imaging spectroradiometer (MODIS) data. The Jianghan Plain, a floodplain located in the middle reaches of the Yangtze River, was selected as the study area. Temporal variations of the enhanced vegetation index (EVI), night land surface temperature (LST), diurnal LST differences (ΔLST), albedo, and the apparent thermal inertia (ATI) were used to analyze the ecological and thermodynamic characteristics of the waterlogged croplands. To obtain pure remote sensing signatures of the waterlogged cropland from mixed pixels, the croplands were classified into different types according to soil and land cover types in this paper, and a linear mixing model was developed by fitting the signatures using the multiple linear regression approach. Afterwards, another linear spectral mixing model was used to get the proportions of waterlogged croplands in each 1 km×1 km pixel. The result showed an acceptable accuracy with a root-mean-square error of 0.093. As a tentative method, the procedure described in this paper works efficiently as a method to monitor the spatial patterns of perennial sub-surface waterlogged croplands at a wide scale.
    Food Science
    Construction of a Food-Grade Expression Vector Based on pMG36e by Using an α-Galactosidase Gene as a Selectable Marker
    GU Xin-xi, TAN Jian-xin, TIAN Hong-tao, ZHANG Yu-lan, LUO Yun-bo , GUO Xing-hua
    2014, 13(8): 1802-1808.  DOI: 10.1016/S2095-3119(13)60625-5
    Abstract ( )   PDF in ScienceDirect  
    Construction of a food-grade expression vector for application to lactic acid bacteria (LAB) is of importance for dairy fermentation system. An α-galactosidase (aga) gene encoding an enzyme degrading melibiose was amplified by PCR from the plasmid pRAF800 of Lactococcus lactis NZ9000. The aga gene was introduced into pMG36e to substitute the primary antibiotic selectable marker of pMG36e, resulting in construction of a new food-grade expression vector pMG36-aga. To testify the expression efficiency of exogenous gene in pMG36-aga, a 1.5 kb long α-amylase (amy) gene from Bacillus licheniformis was cloned by PCR and introduced into the plasmid pMG36-aga. The resultant plasimd pMG36-aga-amy was transformed into L. lactis ML23 by electroporation. The positive clones were selected with the medium containing melibiose as the sole carbon source. The selection efficiency of aga was 8.71×103 CFU with a standard deviation of 9.1×102 CFU mg-1 DNA of pMG36-aga. Furthermore, the SDS-PAGE analysis showed that the pMG36-aga-amy expressed a 56.4 kDa protein which was the same as the putative molecular weight of α-amylase. The starch plate assay also indicated that L. lactis ML23 displayed high activity of α-amylase by expressing of amy gene of pMG36-aga-amy.
    Effects of Cultivar on Phenolic Content and Antioxidant Activity of Naked Oat in China
    TONG Li-tao, LIU Li-ya, ZHONG Kui, WANG Yan, GUO Li-na , ZHOU Su-mei
    2014, 13(8): 1809-1816.  DOI: 10.1016/S2095-3119(13)60626-7
    Abstract ( )   PDF in ScienceDirect  
    To evaluate the effects of naked oat cultivars on their phenolic contents and antioxidant activities, the oat seeds from 21 different cultivars in China were collected, and their major nutritional components, compositions of polyphenols, and antioxidant activities were measured. As the results, oat cultivars affected its phenolic composition and antioxidant activity significantly. Vanillin, chlorogenic acid, ferulic acid, avenanthramide C (Bc), avenanthramide A (Bp), and avenanthramide B (Bf) in oat polyphenols extracts were detected in all cultivars of oat, while caffeic acid, p-coumaric acid and rutin were partly detected. All oat cultivars showed significant free radical scavenging activity, although their activities were lower than that of vitamin C (VC). Different oat varieties showed different antioxidant activities, among which Yanke 1 had the best ability to scavenge •OH ((58.78±1.99) μg mL-1), Baiyan 10 showed the strongest DPPH• ((22.00±0.43) μg mL-1) and ABTS•+ ((6.92±0.44) μg mL-1) scavenging activity, and Dingyou 1 showed good scavenging ability of DPPH• ((22.71±0.42) μg mL-1) and •OH ((81.50±1.73) μg mL-1). In addition, the correlation coefficients of contents between the major nutritional components in different cultivars of oat and phenolic compounds indicated that determination of main nutrients could be used as an easy technique to evaluate approximately the contents and compositions of oat polyphenols, which simplifies the selection of good oat cultivar.
    Comparsion of the Effects of Succinate and NADH on Postmortem Metmyoglobin Redcutase Activity and Beef Colour Stability
    GAO Xiao-guang, WANG Zhen-yu, TANG Meng-tian, MA Chang-wei , DAI Rui-tong
    2014, 13(8): 1817-1826.  DOI: 10.1016/S2095-3119(14)60754-1
    Abstract ( )   PDF in ScienceDirect  
    In two experiments, the effects of succinate and NADH (reduced nicotinamide adenine dinucleotide) on metmyoglobin reductase activity and electron transport chain-linked metmyoglobin reduction were investigated and compared. In experiment 1, metmyoglobin (MetMb), substrate and inhibitors were incubated with mitochondria. Comparsion of the effects of succinate and NADH on MetMb reduction was investigated. The MetMb percentage in sample treated with 8 mol L-1 succinate decreased by about 69% after 3 h incubation, and the effect was inhibited by the addition of 10 mol L-1 electron transfer chain complex II inhibitor malonic acid; the MetMb percentage in samples treated with 2 mol L-1 NADH decreased by 56% and the effect was inhibited by the addition of 0.02 mol L-1 electron transport chain complex I inhibitor rotenone. These results indicated that electron transport chain played an important role in MetMb reduction. Both complex II and complex I take part in the MetMb reduction in mitochondria through different pathways. NADH-MetMb reduction system was less stable than succinate- MetMb system. In experiment 2, the beef longissimus dorsi muscle was blended with different concentrations of succinate or NADH. Enhancing patties with higher concentration of succinate or NADH improved colour stability in vacuum packaged samples (P<0.05). These results verified that mitochondria electron transport chain is related to the MetMb reduction in meat system.