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    20 October 2015, Volume 48 Issue S
    Responses of Migratory Insects to Global Climate Change
    FU Xiao-wei, WU Kong-ming
    Scientia Agricultura Sinica. 2015, 48(S):  1-15.  doi:10.3864/j.issn.0578-1752.2015.S.001
    Abstract ( 313 )   HTML ( 2 )   PDF (2981KB) ( 734 )   Save
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    Responses of organisms to global climate change have caused worldwide concern in recent years. Insect is an important group of organisms closely related with agricultural production, and most of them extend their habitat to unfavorable environment by long-distance migration. Many studies showed that migratory insects are much sensitive to adapt the global climate change by regulating their biological phenology, adult’s morphology and geographical distribution patterns. On the one hand, temperature elevation shorted the first appear date of the overwinter generation, as well as the first flight date and the peak date of the migratory generations in a year, while the migration duration prolonged. On the other hand, global warming changes the damage period of migratory insect pests, aggravates its damages and brings new competitions among them. The phenological synchrony between migratory insect pests and its host plants or natural enemies may be changed owing to increased temperature, which thus alters the insect’s occurrence and biological control in the future. This paper reviews the current advances worldwide in the area, and provides an analysis on potential impact of global climate change to population migration and occurrence principles of insect pests in Chinese agricultural regions.
    Research Progress on the Roles of RNA-Directed DNA Methylation Pathway in Plant Defense
    GENG Shuai-feng, LI Ai-li, MAO Long
    Scientia Agricultura Sinica. 2015, 48(S):  16-22.  doi:10.3864/j.issn.0578-1752.2015.S.002
    Abstract ( 352 )   HTML ( 7 )   PDF (284KB) ( 854 )   Save
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    RNA-directed DNA methylation (RdDM) is an epigenetic process in plants that relies on two core proteins: Dicer-Like 3 (DCL3), which processes long double-stranded RNAs (dsRNAs) into siRNAs, and Argonaute 4 (AGO4), which is involved in siRNA effector functions. RdDM also depends on a specialized transcriptional machinery that is centred around two plant-specific RNA polymerase II (Pol II)-related enzymes called Pol IV and Pol V. Recently, RdDM is found to be involved in plant defense. In this paper, we present an up-to-date overview on RdDM and its related genes during plant defense. We also provide opinions on future research directions for crop defense and breeding.
    Two Promoters Cause Different Fluorescence Expression of egfp in Metarhizium anisopliae
    LIU Shao-fang, WANG Miao-miao, TU Xiong-bing, ZHANG Xiong-peng, NONG Xiang-qun, CAO Guang-chun, WANG Guang-jun, ZHANG Ze-hua
    Scientia Agricultura Sinica. 2015, 48(S):  23-31.  doi:10.3864/j.issn.0578-1752.2015.S.003
    Abstract ( 341 )   HTML ( 6 )   PDF (1227KB) ( 467 )   Save
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    【Objective】The study aimed to determine the effect of two promoters, PgpdA and RP27, on egfp gene expression. It would be important for construction of engineered Metarhizium anisopliae with a new and high-expression promoter in future. 【Method】Two expression vectors, PAN-r-egfp including promoter RP27 and PAN-p-egfp including promoter PgpdA, were constructed with a hph marker gene and a egfp reporter gene, respectively. CaCl2-PEG meditated transformation was used to transfer the two vectors into M. anisopliae strainMa9. The transformants were observed fluorescence intensity of hypha and conidia by Laser Scanning Confocal Microscope.【Result】Among of the hph-resistance transformants from PAN-r-egfp and from PAN-p-egfp transformed, 40% and 31% achieved egfp expression with high fluorescence in M. anisopliae, respectively. Both hypha and conidia of transformants from PAN-r-egfp transformation shined strong fluorescence. But only hypha of transformants from PAN-p-egfp transformation was observed fluorescence, its conidia failed to produce fluorescence.【Conclusion】The egfp gene expression was influenced by different promoters and different development stages of M. anisopliae. The promoter RP27 could drive egfp gene expression either in hypha or in conidia of M. anisopliae Ma9. The initiating action of promoter PgpdA may be inhibited at conidiating stage of M. anisopliae Ma9, resulting in failure of egfp expression at the stage.
    Effects of Interspecific Interactions on Nitrogen Absorption,Nodulation and Nitrogen Fixation in Oat‖Soybean and Oat‖Mung Bean Intercropping Systems
    YANG Ya-dong, FENG Xiao-min, REN Chang-zhong, HU Yue-gao, ZHANG Wei-jian, ZENG Zhao-hai
    Scientia Agricultura Sinica. 2015, 48(S):  32-39.  doi:10.3864/j.issn.0578-1752.2015.S.004
    Abstract ( 349 )   HTML ( 6 )   PDF (450KB) ( 308 )   Save
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    【Objective】The objective of this experiment was to study the effects of interspecific interactions on nitrogen absorption, nodulation and nitrogen fixation in oat‖soybean and oat‖mung bean intercropping systems and search a higher nitrogen absorption efficiency oat‖legume system. 【Method】The experiment was conducted to determine the effects of interspecific interactions on nitrogen content, nodulation characteristics and nodule nitrogenase activity of legume in oat‖soybean and oat‖mung bean intercropping systems by seven treatments (oat monoculture, soybean monoculture, mung bean monoculture, oat‖soybean without root barriers, oat‖soybean with root barriers, oat‖mung bean without root barriers and oat‖mung bean with root barriers) with pot experiment at Baicheng Academy of Agricultural Sciences of Jilin Province in 2013 and 2014 oat, soybean and mung bean growing seasons. 【Result】The results indicated that: (1) Nitrogen content increased significantly in stem, leaf and spike (P<0.05), and no significant difference in root (P>0.05) of oat were observed in oat‖soybean and oat‖mung bean systems without root barriers compared with monoculture, respectively; (2) Interestingly, different results of legume nitrogen content were obtained in mung bean and soybean, nitrogen content increased significantly in stem, leaf and bean (P<0.05) of mung bean in oat‖mung bean system, but no significant difference was observed (P>0.05) of soybean in oat‖soybean system compared with monoculture, respectively; (3) There were significant increase, with up to 38.45%, 26.38%, 9.09% in 2013, and 28.57%, 20.16%, 2.23% in 2014, in number of nodules, nodules weight and nodules nitrogenase activity of mung bean (P<0.05) in oat‖mung bean, respectively; but no significant impact found in oat‖soybean system, with up to 26.22%, 28.30% in 2013, and 31.29%, 36.85% in 2014, in number of nodules, nodules weight, respectively; (4) Nitrogen absorption of ground organs in oat had positive correlation, while root had negative correlation with number of nodules, nodules weight and nodules nitrogenase activity in legumes, respectively. 【Conclusion】Our results demonstated that oat‖mung bean had an higher nitrogen absorption efficiency and nitrogen fixation ability, which could provide guidance for oat‖legume production.
    Effects of γ-Poly Glutamic Acid on Mineral Nutrient Supply in Substrate and Growth and Development of Watermelon Plug Seedlings
    CHU Qun, DONG Chun-juan, SHANG Qing-mao
    Scientia Agricultura Sinica. 2015, 48(S):  40-48.  doi:10.3864/j.issn.0578-1752.2015.S.005
    Abstract ( 458 )   HTML ( 6 )   PDF (423KB) ( 451 )   Save
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    【Objective】Plants grown in cells of plug tray often show limited growth due to low levels of water holding capacity and fertilizer conservation in the medium. Steady supply of water and fertilizer is critical to produce strong seedlings. The aim of this study was to evaluate the effects of γ-poly glutamic acid on nutrient availability of substrate and plant growth and development of watermelon seedlings. 【Method】 Watermelon seedlings were growth in the 50 cell-plug trays, with the substrates containing peat moss, vermiculite and perlite as the growth medium. Different amount of γ-poly glutamic acid (0, 1, 3, 5, 10 kg·m-3) were mixed with the substrates before sowing. Physicochemical and biological properties of substrates and growth parameters of watermelon plug seedlings were measured.【Result】By adding γ-poly glutamic acid, the watermelon seedling substrate showed increased water filled porosity, water holding capacity, EC value and decreased pH value. During watermelon plug seedlings development, available N, P, K, Mg in the substrates was enhanced. Of these nutrient elements N content in the substrate enhanced by γ-poly glutamic acid application was the most. The NH4+-N and NO3--N in the substrate was increased by 1.2 and 2.6 times respectively compared with the control when the seedling production was done. Microbial activity, neutral phosphatase activity and catalase activity were also increased significantly. The effects of γ-poly glutamic acid were better at the late growth stage than the early growth stage which depended on the amount of γ-poly glutamic acid. At the early growth stage adding γ-poly glutamic acid significantly increased the leaf chlorophyll content and had no significant effect on the root activity. High amount addition of γ-poly glutamic acid suppressed the growth and development of watermelon plug seedlings especially of the root growth. At the late growth stage adding γ-poly glutamic acid significantly increased the leaf chlorophyll content and the root activity. The optimum amount addition of γ-poly glutamic acid enhanced the growth and development of watermelon plug seedlings. The shoot biomass and leaf area got the biggest value under 3 kg·m-3 γ-poly glutamic acid treatment which were increased by 22.6% and 55.7% respectively compared with that in the control. At this treatment seedling index got the higher value which was increased by 11.8% compared with that in the control.【Conclusion】The results indicated that γ-poly glutamic acid application can effectively improve the physicochemical and biological properties of substrates and enhance the growth and development of the watermelon seedlings. The water and fertilizer retention capacity of substrates was enhanced by γ-poly glutamic acid. The optimum amount of γ-poly glutamic acid was 3 kg·m-3 based on the physical and chemical properties of substrates and the growth and development of watermelon seedlings.
    Immunomagnetic Separation for Foodborne Pathogen Detection in Raw Milk
    LAN Xin-yi, LIU Hui-min, ZHENG Nan, LI Fa-di, WANG Jia-qi
    Scientia Agricultura Sinica. 2015, 48(S):  49-57.  doi:10.3864/j.issn.0578-1752.2015.S.006
    Abstract ( 371 )   HTML ( 5 )   PDF (385KB) ( 836 )   Save
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    Microbial community in raw milk is an important factor influencing quality and safety of the dairy products, as it reflects hygienic conditions during milking and storage of raw milk in the bulk tank. Foodborne pathogens of high public health concern, including Staphylococcus aureus, Listeria monocytogenes, Salmonella, Bacillus cereus and Escherichia coli, seriously affected human health. Traditional culture-based methods, ELISA, LAMP and PCR are used for detection of pathogens. Detection sensitivity of existing methods are low without pre-enrichment, limiting the methods directly used for rapid detection of pathogen in raw milk. Immunomagnetic separation has been suggested to reduced the analysis time and improved the sensitivity detection of pathogenic microorganisms. The methods were successfully used to detect Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Escherichia coli, Mycobacterium avium, Campylobacter jejuni, Helicobacter pylori, Campylobacter spp, Yersinia spp and Chlamydia trachomatis. Immunomagnetic separation combined with spectrophotometer, Chrom agar, real-time PCR, fluorescence immunochr omatographic assay or colloidal gold lateral flow assay were effective for detection and isolation of Escherichia coli. Immunomagnetic separation combined with Chrom agar, colorimetric detection, fluorescence immunochr omatographic assay and LAMP were effective for detection and isolation of Staphylococcus aureus. Immunomagnetic separation combined with qPCR, ELISA, quantum dots and LAMP were effective for detection and isolation of Salmonella spp. Immunomagnetic separation combined with flow cytometry, selective medium and real time PCR were effective for detection and isolation of Listeria monocytogenes. Recent progress in the application of immunomagnetic separation technology for the mainly pathogens in raw milk was reviewed, and the problems and development trends about immunomagnetic separation were analyzed and discussed in the paper.
    Phylogenetic Analysis of Seven Different Geographical Populations of Wild Boar in China
    BAI Li-jing, LIU Bo, LI Lin, MU Yu-lian, LI Kui
    Scientia Agricultura Sinica. 2015, 48(S):  58-66.  doi:10.3864/j.issn.0578-1752.2015.S.007
    Abstract ( 333 )   HTML ( 5 )   PDF (535KB) ( 958 )   Save
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    【Objective】 The mitochondria DNA is the unique genetic material outside the nuclear within eukaryotic cells, having a relatively constant and different bioinformation from the nucleus DNA. The analysis of mitochondria DNA sequence could provide theoretical basis for researching the origin and evolution of the species. Therefore, based on the analysis of mitochondria DNA sequence mutation between different wild boars, we could study the genetic resources of wild boar from different geographical populations, and explain genetic relationships between different subspecies in China. 【Method】A total of 26 wild boars belonging to seven regions, including Inner Mongolia, Sichuan, Shanxi, Zhejiang, Jiangxi, Hunan and Fujian, were selected for DNA extraction using ear tissues and/or tail tissues based on Phenol - chloroform method. For each individual, according to Covaris System (Life Technologies), 3μg of DNA was sheared into DNA fragments of 200-800 bp. The DNA fragments were treated based on the Illumina DNA sample preparation protocol. Fragments were ending repaired, A-tailed, ligated to paired-end adaptors and PCR amplified with 500-bp inserts for library construction. Sequencing was performed to generate 125bp paired-end reads on the HiSeq2500 platform (Illumina). To compare the difference between wild boars in China and other countries, we downloaded the resequencing data of 12 wild boars, including six European wild boars, one Japanese wild boar, one Sumatra wild boar and four Chinese wild boars from NCBI website. We used the 12 resequencing data of wild boars and 26 resequencing data sequenced by ourselves to identify the mutation between the 38 wild boars. Based on the average of sequencing quality of paired-end reads, we filtered out the quality of paired-end reads less than the Q30. To identify the SNPs between 38 wild boars in whole mitochondria DNA sequence, the software BWA and samtools were used in this study. And then, we used minor allele frequency (MAF) more than 0.05 to filter SNP in wild boars population. Based on the reliable SNPs, we used maximum likelihood (ML) to construct the phylogenetic tree, principal component analysis (PCA) and nucleotide diversity analysis (π) in 38 wild boars. 【Result】A total of 226 SNP (0.014 SNPs/bp) were identified in 38 wild boars in whole genome sequence of mitochondria DNA, including 33 SNPs (0.028 SNPs/bp) in D-loop region. Based on different geographical populations, the 38 wild boars could be divided into nine groups, including Sumatra, Europe, Japan, Shanxi, Sichuan, Hunan, Jiangxi, Zhejiang and Inner Mongolia. For the analysis of GC content in whole genome sequence of mitochondria DNA in each group, the GC contents were not much changed, 34.7% for A, 26.2% for C, 13.3% for G and 25.8% for T, respectively. For the D-loop region, compared to whole genome sequence of mitochondria DNA , A content reduced 1% and G content raised 1%. The analysis of phylogenetic tree and PCA show that there was significantly divided into two groups between European group and Asian group. It indicates that the two groups were independent evolution. On the other hand, seven different geographical populations in China could be divided into three subspecies (Mongolian, Sichuan-Shaanxi, and South China wild boar). The results of nucleotide diversity analysis showed that the genetic distance were smaller (average π is 0.0022; range from 0.00024 to 0.0037) amongst the wild boars in China. However, there was large nucleotide diversity (average is 0.0049; range from 0.0044 to 0.0052) between European group and Chinese group. Sumatra and Japan groups were average 0.0025 nucleotide diversity compared to Chinese group. It indicates that comparing to Sumatra and Japanese wild boars, the European ones have large nucleotide diversity with Chinese wild boars. 【Conclusion】 Although there were abundant polymorphism haploid type in Chinese wild boars, the risk of losing the genetic diversity were increasing, which suggested that the scientific planning and protection of germplasm resources should be strengthened.
    Advances of the Regulation of Amino Acids-Mediated-mTORC1 Upstream Pathway in Mammalian Cells
    LUO Chao-chao, ZHENG Nan, ZHAO Sheng-guo, LI Song-li, WEN Fang, WANG Jia-qi, ZHANG Yang-dong
    Scientia Agricultura Sinica. 2015, 48(S):  67-74.  doi:10.3864/j.issn.0578-1752.2015.S.008
    Abstract ( 312 )   HTML ( 4 )   PDF (1120KB) ( 1103 )   Save
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    In mammalian cells, the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway is one of the main signaling pathways that regulate life activities, such as cell proliferation, growth, protein synthesis and cell autophagy and so on, in response to the change of nutrients (such as amino acids), hormones (such as growth factors) and energy. Amino acid is one of the most important regulatory factors in nutrients factors that regulate mTORC1 signaling pathways in cells. In mammalian cells, mTORC1 is phosphorylated and activated by amino acid, and then phosphorylated mTORC1 participates in the translation process of protein and promotes the protein synthesis by activating two downstream molecules, ribosomal protein S6 kinase 1 (S6K1) and eukaryotic translation initiation factor 4E binding protein 1 (4EBP1). But about the regulatory pathways and molecular mechanism of amino acids-mediated-mTORC1 upstream pathway is still poorly understood. Studies have shown that, the regulation of amino acid on the mTORC1 upstream pathways may have several different models: (1): “inside-out” model, in this model, amino acid is transported into lysosome, and then the amino acid recruits mTORC1 to the lysosomal surface and activates mTORC1 by activating SLC38A9, v-ATPase, Ragulator and Rag GTPase, and amino acid activates these proteins in lysosome; (2): GATOR - Rag GTPase model, in this model, amino acid activates mTORC1 by activating or inhibiting Sestrins, GATOR2, GATOR1, Skp2 and Rag GTPase, and amino acid activates or inhibits these proteins in cytoplasm; (3): Leucine regulatory model, Leucine activates mTORC1 by leucyl-tRNA synthetase and Rag GTPase; (4): Glutamine regulatory model, glutamine activates mTORC1 by Glutamine metabolic enzymes, Alpha ketone glutaric acid and small GTPase ADP ribose base factor 1 (Arf1); (5): Other regulatory factors, besides above models, there are also some signaling molecules playing important role in the regulation of amino acids-mediated-mTORC1 upstream pathway, but not belonging to the above models, such as MAP4K3, B/PR61 epsilon, p62, T1R1 / T1R3, TRAF6 and SH3BP4, etc. This review summarized the regulation and the possible pathways of amino acids-mediated-mTORC1 upstream pathway in mammalian cells.
    Research Advance on the Relationship Between Thioredoxin- Interacting Protein and Glucose Metabolism in Oocytes
    PANG Yun-wei, SUN Ye-qing, DU Wei-hua, HAO Hai-sheng, ZHAO Xue-ming, WANG Dong, ZHU Hua-bin
    Scientia Agricultura Sinica. 2015, 48(S):  75-85.  doi:10.3864/j.issn.0578-1752.2015.S.009
    Abstract ( 321 )   HTML ( 1 )   PDF (1315KB) ( 550 )   Save
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    Thioredoxin-interacting protein (TXNIP) is a member of the thioredoxin (Trx) super family of proteins, which is the only α-arrestin family member that binds to and negatively regulates Trx. TXNIP can inhibit the function of Trx system by binding Trx, and act as a competitive inhibitor to remove Trx from apoptosis signal-regulating kinase 1 (ASK1). TXNIP is closely related to the cellular reduction-oxidation (redox) state and plays an important role in cell apoptosis. TXNIP is a critical regulator of glucose metabolism. High glucose recruits carbohydrate response element-binding protein (ChREBP) and the transcription factor MondoA:Mlx to the TXNIP promoter and mediates glucose-induced TXNIP expression. Histone deacetylase 1(HDAC1), nuclear factor Y (NF-Y) and the forkhead boxO1 transcription factor (FOXO1) have been reported to regulate the transcription of TXNIP. TXNIP can also inhibit cell proliferation by repressing cyclin-dependent kinase activity. Some studies have found that elevated TXNIP levels induce beta cell apoptosis and inhibit insulin signaling pathway, then promote the occurrence of diabetes and the associated medical comorbidities. Clinical data suggest that hyperglycemia induced by diabetes seriously affects metabolic activity and quality in oocytes. Glucose is the substrate for many cellular functions that can regulate the process of meiosis, and is metabolised by glycolysis pathway, the pentose phosphate pathway, the hexosamine biosynthesis pathway and the polyol pathway. Recent studies have revealed that upon specific depletion of TXNIP, most of oocytes were arrested at metaphate I (MI) stage, which exhibited disturbed actin networking and upregulated glucose uptake and lactate production, indicating that TXNIP is an important regulator of glucose metabolism in oocytes. In summary, it may exist complex regulatory relationships between TXNIP and glucose metabolism in oocytes. TXNIP may be a critical target mediating glucose metabolism in oocytes, and further study will provide important theoretical reference for abnormal metabolic studies. Hence, the structure and regulatory mechanism of TNXIP, pathways of glucose metabolism in oocytes and the relationship between TXNIP and glucose metabolism in oocytes are reviewed in this paper.
    Progresses of Research on Ruminal Urea Transport, Metabolism and Its Regulation
    WANG Peng-peng, ZHENG Nan, Wang Jia-qi, ZHAO Sheng-guo
    Scientia Agricultura Sinica. 2015, 48(S):  86-93.  doi:10.3864/j.issn.0578-1752.2015.S.010
    Abstract ( 385 )   HTML ( 7 )   PDF (1932KB) ( 616 )   Save
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    The urea from the diet or recycled from blood into rumen is hydrolyzed by ruminal bacteria to ammonia, which acts as the major source of nitrogen for many ruminal bacterial growth. Urea is usually used as a replacement for parts of dietary nitrogen in practice, for cost reduction. The common recommendation for urea addition is less than 1% of the concentrate portion of the diet, approximately 135 g/cow daily, or not more than 20% of total dietary crude protein. Around 40% to 80% of the urea nitrogen synthesized in the liver can return to the gastrointestinal tract, where approximately 35% to 55% of this nitrogen will take part in bacterial anabolism. Urea transporter, distributed in epithelial layer of rumen papillae, plays an important role in endogenous urea transport from blood to rumen, which is regulated by ammonia concentration in the rumen or urea concentration in the blood or the both. There are various ureolytic bacteria in the rumen, which belong to Firmicutes, Actinobacteria, γ-Proteobacteria, and uncultured bacteria. Urease is the key enzyme in the pathway of urea hydrolysis. Urea is rapidly hydrolyzed into ammonia and carbon dioxide by the catalysis of urease in the rumen. However, the rate of urea hydrolysis is about four times than that of ammonia assimilation, resulting in the reduction of urea utilization efficiency. The diffusion of excess ammonia into blood also lead to increasing chance of toxicity for ruminants. In addition, the excretion of residual ammonia in feces and urine possibly causes the environmental pollution. Thus, ruminal urea transporter, metabolism and its regulation play an important role in the nitrogen balance and body homeostasis of ruminants. This article mainly summarized the application of urea in the diets of ruminants, urea transporter, the taxa and diversity of rumen ureolytic bacteria, and the mechanism and regulation of urea metabolism by ruminal bacteria.
    Effects of Ensiling and Natural Drying on Composition and Abundance of Bacterium of Corn Stalk Analyzed by MiSeq Sequencing Technology
    TAO Lian, DIAO Qi-yu
    Scientia Agricultura Sinica. 2015, 48(S):  94-103.  doi:10.3864/j.issn.0578-1752.2015.S.011
    Abstract ( 282 )   HTML ( 4 )   PDF (735KB) ( 598 )   Save
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    【Objective】The microbes carried by corn stalk maybe had the potential impact on the nutrients absorption and utilization of nutrients and animal health, due to the large amount of feeding. The objective of the present study was to investigate the effect of ensiling and natural drying of corn stalk silage on its bacterium composition and abundance, and try to provide a theoretical basis for the utilization of corn stalk from the microbiological point of view. 【Method】 The effect of ensiling and natural drying on composition and abundance of bacterium of corn stalk was analyzed using MiSeq sequencing technology. 【Result】The results showed that, the overall number of OTUs detected by the analysis reached 10887 based on ≥ 97% nucleotide sequence identity between reads, and the rarefaction curve of each sample was flattening. These implied that the sequencing depth was sufficient to reflect the vast majority of bacterium in the samples. There were differences and similarities on the composition and abundance of bacterium during stuff, dried and silage samples of corn stalk. Flora constitute of dry corn stalks was the most complex, followed by corn stalk stuff and the silage. The numbers of Proteobacteria plylum, Gammaproteobacteria class, Enterobacteriales order, Enterobacteriaceae family in dry corn stalk were 96.53%, 90.67%, 81.42% and 81.42%, which were significantly increased compared with stuff of corn stalk (P<0.05); while the numbers of Proteobacteria plylum, Gammaproteobacteria class, Enterobacteriales order, Enterobacteriaceae family in corn stalk silage were 55.93%, 37.51%, 25.03% and 25.03%, which were significantly decreased compared with stuff and dry corn stalk (P<0.05). 4) The numbers of Firmicutes phylum, Bacilli class, Lactobacillales order, Lactobacillaceae family, and Pediococcus genus in corn stalk silage were 39.10%, 38.91%, 38.81%, 32.08% and 28.14%, which were significantly increased compared with stuff and dry corn stalk (P<0.05); while the numbers of Firmicutes phylum, Bacilli class, Lactobacillales order, Lactobacillaceae family, and Pediococcus genus in corn stalk silage were only 2.47%, 2.45%, 2.39%, 1.55% and 1.32%. 【Conclusion】 There was significant difference on bacterium composition and abundance between dried and silage samples of corn stalk; the using method of ensiling was better than natural dried corn stalk. MiSeq sequencing technology could provide the information of composition and abundance of flora.
    Antibiotics Pollution Characteristics and Control of Livestock Breeding Industry
    ZHI Su-li, ZHANG Ke-qiang
    Scientia Agricultura Sinica. 2015, 48(S):  104-112.  doi:10.3864/j.issn.0578-1752.2015.S.012
    Abstract ( 308 )   HTML ( 2 )   PDF (377KB) ( 550 )   Save
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    At present, more and more attention has been paid on the antibiotics pollution. About more than a half of the total antibiotics is used in livestock breeding industry. Veterinary antibiotics (VAs) have become an important source for global antibiotics pollution. Nowadays, increasing number of studies reported on the residual concentration of veterinary antibiotics under different conditions and in different environmental matrixs. However, the pollution characteristics of veterinary antibiotics have not been analyzed. Although various VAs removal technologies were studied, it is important to propose an appropriate source control technology. On the basis of existing data, the paper analyzed the pollution characteristics of VAs. Meanwhile, it also analyzed the present control technologies of VAs and pointed out the tendency of VAs pollution controlling. The results are as follow: The most developed economic areas in China (usually East China) have higher residual concentration of VAs, and the order of TCs is OTC>CTC>TC; South China usually has lower VAs residual concentration and different prescription habits with other areas. Although different results from different authors, pig usually has higher residual concentration of VAs in excrement which should be paid more attention. For most VAs, they had much lower concentrations in summer than those in winter, but some SAs in contrast. Therefore, according to the characteristics of VAs pollution, different source control strategies can be established. The succedaneum of VAs is the essential way to control VAs usage. In addition, the precise usage of VAs is a helpful way. Although various VAs removal technologies were studied, the control technology should focus on the prior removal by magnetic adsorbent or catalyzed oxidation before VAs spreading into environment. Moreover, degradation mechanism and intermediate products should be emphasized in the later research work. This will provide a theoretical foundation for source control and removal technology of VAs.