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Table of Content

    16 December 2013, Volume 46 Issue 24
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
    Progress in Research of Chromosome Segment Substitution Line Carrying Overlapping Chromosome Segments of the Whole Wild Rice Genome
    YE Xin-Fu, YANG De-Wei
    Scientia Agricultura Sinica. 2013, 46(24):  5075-5080.  doi:10.3864/j.issn.0578-1752.2013.24.001
    Abstract ( 435 )   PDF (335KB) ( 843 )   Save
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    Wild rice has adapted to weather and unfavorable environments under natural selection. It has been well recognized as a natural gene bank that conserves a lot of specific genes presently not available for extinct in the cultivated rice. The chromosome segment substitution lines (CSSLs) were perfect materials for analysis of gene. Developing the CSSLs can not only search and use the new gene resource,but also can achieve the development of span mode of plant molecular breeding from utilizing single gene to synthetically exploiting genome. In this paper, the principle of developing the CSSLs was described, the research progress in construction and application was reviewed, and the prospect was discussed. So that it could provide a base for utilization of wild rice resource.
    Main, Environmentally Interacted and Epistatic QTL for Seed Shape Traits in Soybean
    LIANG Hui-Zhen-1, YU Yong-Liang-1, YANG Hong-Qi-1, ZHANG Hai-Yang-1, DONG Wei-1, DU Hua-1, CUI Wei-Wen-1, LIU Xue-Yi-2, FANG Xuan-Jun-3
    Scientia Agricultura Sinica. 2013, 46(24):  5081-5088.  doi:10.3864/j.issn.0578-1752.2013.24.002
    Abstract ( 426 )   PDF (572KB) ( 615 )   Save
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    【Objective】In this study, the mixed linear model method was used to identify the main-effect, environmentally interacted and epistatic quantitative trait loci (QTLs) for seed shape traits in soybean.【Method】A total of 447 recombinant inbred lines (RILs) derived from a cross of Jindou 23 (cultivar, female parent) and ZDD2315 (semi-wild, male parent) were scanned by 232 SSR markers and measured for the above traits in 2010 to 2012. The marker information was used to construct linkage groups. All the phenotypic values along with marker and linkage-group information were used to detect all kinds of QTLs for the above traits.【Result】 Seven QTLs for seed length, seed width, seed thickness, seed length-to-width ratio, seed length-to-thickness ratio and seed width-to-thickness ratio, were mapped and placed on linkage groups D2, C2, J_2 and O. Positive additive effects of QTLs for seed length, seed length-to-thickness ratio and seed width-to-thickness ratio were observed and their elite alleles were derived from Jindou 23. Three pairs of additive × additive epistasis and their interactions with environment for seed width, seed width-to-thickness ratio were detected.【Conclusion】The main-effect, epistatic and environmentally interacted QTLs have the biggest, middle and smallest influences on the above traits, respectively.
    TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY
    Effects of Sowing Patterns on Establishment Quality, Grain Yield and Production Benefit of Intercropping Wheat in Hilly Countries
    TANG Yong-Lu, LI Chao-Su, WU Chun, WU Xiao-Li, Huang-Gang, MA Xiao-Ling
    Scientia Agricultura Sinica. 2013, 46(24):  5089-5097.  doi:10.3864/j.issn.0578-1752.2013.24.003
    Abstract ( 407 )   PDF (601KB) ( 826 )   Save
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    【Objective】Southwestern region is one of the most important wheat production areas in China where wheat concentrates mainly in hilly regions and intercrops with maize or other crops with low mechanization and benefit. Its crucial for boosting regional wheat industry to increase mechanization level of wheat production.【Method】Experiments on different soil types in hilly region of Sichuan basin were conducted during wheat growing seasons in 2010-2011 and 2011-2012 to test the performance and adaptability of small planter driven by micro-cultivator. Treatments included CK (i.e. Sparse-Great Hill which means few hills per unit area but many seeds in a hill and all operations are completed by hands), 2B-4 seeder (only sowing seeds without fertilizing function) and 2BFS-4 seeder (with both sowing and fertilizing functions). 【Result】 A significant difference in establishment quality of wheat was observed in 2010-2011 growing season with dry condition during sowing period. 2B-4 had faster emergence, more uniform distribution of seedlings, and higher quality of individuals and community at early and middle growing stages than other treatments, with a similar trend between two soil types. Seeding efficiency of 2B-4 and 2BFS-4 was significantly higher than that of CK, but their seeding cost was significantly lower than that of CK. Mean grain yields of 2B-4 and 2BFS-4 over growing seasons and soil types were higher than CK by 12.7% and 8.9%, and their mean net benefits were higher than CK by 70.6% and 50.6%, respectively. 【Conclusion】2B-4 was a mature seeding type and worthy of application for hilly fields of Southwestern China based on grain yield, benefit and adaptability.
    Effects of Irrigation with Micro-Sprinkling Hoses of Different Sprinkling Angles on Soil Water Distribution and Water Consumption Characteristics and Grain Yield of Winter Wheat
    MAN Jian-Guo, WANG Dong, ZHANG Yong-Li, SHI Yu, YU Zhen-Wen
    Scientia Agricultura Sinica. 2013, 46(24):  5098-5112.  doi:10.3864/j.issn.0578-1752.2013.24.004
    Abstract ( 377 )   PDF (825KB) ( 714 )   Save
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    【Objective】The objective of this experiment was to study the effects of irrigation with micro-sprinkling hoses of different sprinkling angles on soil water distribution and water consumption characteristics and grain yield of winter wheat, to provide a scientific basis for innovating water-saving irrigation technology and achieving high-yield and high-efficiency cultivation of wheat. 【Method】Field experiments were conducted with high-yield winter wheat cultivar Jimai 22 in Yan Zhou, Shandong Province during 2010-2012 growing seasons. Five irrigation treatments were designed: T0, no irrigation during the whole growth stage; T1, T2, T3, T4 were irrigated with micro-sprinkling hose, and the sprinkling angles were 35°, 50°, 65° and 80°, respectively. The length of all micro-sprinkling hose was 40 m. The hose was put at the middle of the border along the direction of wheat rows, which irrigated the four rows (L1-L4) besides it, the irrigation width was 1.6 m in field.【Result】Under the condition of micro-sprinkling irrigation applied at jointing and anthesis stages, the soil water content in 0-200 cm soil layer from L1 to L4 of each sampling area in the same treatment had the same change law. The soil water content in the upper soil layers decreased with increasing the distance from inter-rows of wheat to micro-sprinkling hose in T1, T2 and T3 treatments, and the irrigation water distribution uniformity in soil increased with increasing the sprinkling angle from 35° to 65°. There was no significant difference among each inter-rows of wheat in soil water content of 0-200 cm soil layer in T4 treatment, and the irrigation water distribution uniformity in soil of T4 treatment was the highest. Compared to other treatments, the soil water consumption in 40-80 cm soil layer from jointing to anthesis and in 20-80 cm soil layer from anthesis to maturity in T4 treatment were the highest, while the water consumption from jointing to anthesis, irrigation amount in anthesis and total irrigation amount, total water consumption in T4 treatment were the lowest. The grain yield, yield water use efficiency and soil water use efficiency in T4 treatment were higher than those in T1, T2 and T3 treatments. 【Conclusion】As far as high-yield and high-water use efficiency were concerned in this experimental, the most appropriate treatment for recommendation was the one which irrigated with sprinkling angle of 80° micro-sprinkling hose at jointing and anthesis stages.
    Construction of a Multidimensional Knowledge Service System for Agricultural Sci-Tech Innovation
    ZHAO Rui-Xue, MENG Xian-Xue, KOU Yuan-Tao, XIAN Guo-Jian, ZHU Liang
    Scientia Agricultura Sinica. 2013, 46(24):  5113-5122.  doi:10.3864/j.issn.0578-1752.2013.24.005
    Abstract ( 294 )   PDF (615KB) ( 740 )   Save
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    【Objective】The objective of this study is to construct a multidimensional knowledge service system for meeting agricultural researchers’ needs of multi-level knowledge services. 【Method】Key technologies including the acquisition and digital integration of Sci-Tech information, intelligent data preprocessing methods and tools, knowledge organization systems, as well as integrated and personalized knowledge services were comprehensively utilized, optimized and integrated into applications.【Result】A multidimensional knowledge service system was established to carry out service application for different levels of agricultural scientific research personnel. It basically provided one-stop public and integrated service to researchers. It take supplying different research institutes, academic teams and professional fields with personalized and in-depth knowledge services as innovation, and supporting online academic exchange and collaborative research as expansion.【Conclusion】The technological system of “one-stop public and integrated service + personalized and in-depth knowledge service” has been applied into the innovative research practices of CAAS and some provincial academies of agricultural sciences . Meanwhile, the common technologies, systems and tools of information service put forward in this study have significant leading, demonstrative and propagable effects on related fields.
    PLANT PROTECTION
    Comparative Analysis of Gene Expression Profiles of Rice Responding to Different Races of Magnaporthe grisea
    JIANG Zhao-Yuan-1, 2 , 3 , REN Jin-Ping-1, 2 , 3 , LIU Xiao-Mei-1, 2 , 3 , ZOU Xiao-Wei-1, 2 , 3 , GUO Xiao-Li-1, 2 , 3 , WANG Ji-Chun-1, 2 , 3 , WEN Jia-Wei-2, LIU Wen-Ping-2, XIA Hai-Feng-4, HONG De-Zhi-5
    Scientia Agricultura Sinica. 2013, 46(24):  5123-5131.  doi:10.3864/j.issn.0578-1752.2013.24.006
    Abstract ( 444 )   PDF (587KB) ( 820 )   Save
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    【Objective】The objective of this study is to investigate the gene expression profiles of rice at 48 h after compatible and incompatible Magnaporthe grisea inoculation, and to explore the molecular mechanism of rice resistance to different M. griseas races.【Method】mRNA expression in compatible and incompatible rice was profiled using the Affymetrix microarray assay. GO (gene ontology) analyses were conducted on differentially expressed genes using a free web-based Molecular Annotation System 3.0 (MAS 3.0). Finally, the quantitative real-time PCR was used to verify the expression patterns of genes selected from microarray in rice. 【Result】Among the 49 824 transcripts on the array, about 24 000 transcripts were detected in rice. And 1 028 genes showed a fold change (FC) of more than 2.5. There were 460 genes were up-regulated and 568 genes were down-regulated in incompatible rice. Subsequently, real-time PCR was performed to validate four genes screened out by the microarray approach and sufficient consistency was observed between the two methods. The differentially expressed genes were functionally categorized by GO term analysis, which demonstrated that the gene set encoded proteins that function in signal transduction, enzyme regulation, transcription, molecule transport, and so on. 【Conclusion】 The result of gene expression profiles show that there were significant differences inthe compatible and incompatible rice. The genes differentially expressed in rice identified by microarray and functionally categorized by GO term analysis will help further understanding of plant disease resistance mechanisms in plant-pathogen interaction and may be beneficial to provide a new method for control of rice blast.
    Characterization of T-DNA Insertion Flanking Genes of Enhanced-Conidiation Ustilaginoidea virens Mutant A2588
    YU Jun-Jie, NIE Ya-Feng, YU Mi-Na, YIN Xiao-Le, HU Jian-Kun, HUANG Lei, CHEN Zhi-Yi, LIU Yong-Feng
    Scientia Agricultura Sinica. 2013, 46(24):  5132-5141.  doi:10.3864/j.issn.0578-1752.2013.24.007
    Abstract ( 354 )   PDF (674KB) ( 789 )   Save
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    【Objective】The objective of this study is to clone the mutated gene, which causes enhanced conidiation of the T-DNA insertional mutant A2588, and to shed light on the conidiation mechanism in Ustilaginoidea virens.【Method】The sporulation, conidial germination, mycelial growth rate and heat tolerance of the mutant A2588 were determined, and wild-type strain 70-22 was employed as the control. hiTAIL-PCR and RACE were used to identify the insertional T-DNA flanking genes in A2588, and RT-PCR were applied to analyzed the expression level of the T-DNA flanking genes as well. Additionally, the function of T-DNA insertion region in the genome of A2588 was bioinformatically predicted. 【Result】Compared to the wild-type U. virens strain 70-22, the mutant A2588 produced more than 10 folds of conidia in PS broth and approximately 20 folds of conidia in MM liquid medium, and formed more compact mycelial balls in PS. Despite of having an equivalent mycelial growth rate to 70-22, A2588 exhibited a shorter sporulation cycle, a lower conidia germination rate and slower recovery after heat treatment on the PSA and MM solid media. The T-DNA in mutant A2588 was found inserting into the promoter region of spo76 and reduced expression level of this gene. 【Conclusion】 Due to the partial damage of the spo76 promoter, the spo76 expression level in mutant A2588 was reduced and sporulation cycle of A2588 was accelerated. This may result in enhanced conidiation of U. virens mutant A2588.
    The Operon, Structure and Biological Activities of the Lipopeptide Fengycin Produced by Bacillus subtilis 916
    LUO Chu-Ping-1, 2 , WANG Xiao-Yu-1, ZHOU Hua-Fei-1, 2 , LIU You-Zhou-1, CHEN Zhi-Yi-1, 2
    Scientia Agricultura Sinica. 2013, 46(24):  5142-5149.  doi:10.3864/j.issn.0578-1752.2013.24.008
    Abstract ( 499 )   PDF (690KB) ( 493 )   Save
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    【Objective】The objective of this study is to clone and sequence the Fen operon responsible for synthesis of the fengycin from Bacillus subtilis 916 and determine the structure and biological activities of the Fen operon. 【Method】Genome sequence and PCR were performed to clone the Fen operon. Analysis of the Fen operon genetic structure was made by using bioinformatics. The Fen mutant BSFG was constructed by the homologous recombination. Fengycin produced by the Bs916 and mutant was analyzed by the reversed-phase high-performance liquid chromatography (HPLC). The molecular weight of the fengycin was determined by the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MS). The antifungal activities and hemolytic activities were evaluated in the form of a flat plate. 【Result】The 37.67 kb Fen operon responsible for synthesis of fengycin was identified and cloned from B. subtilis 916. The operon contained five ORFs designated FenA, FenB, FenC, FenD andFenE, respectively. The amino acid sequences encoded by the Bs916 Fen operon share 65% similarity with the counterpart amino acid sequences from the Bs168 Fen operon. The results of HPLC analysis of lipopeptides produced by wild-type Bs916 and mutant BSFG showed the Fen operon responsible for fengycin synthesis. The molecular weights determined by MS were 1 449.8, 1 463.9, 1 477.9 and 1 491.9, 1 505.9 Da showed fengycin produced by Bs916 contained five homologues. The first three homologues were differed by a structure of –CH2 and their peptide moiety primary structure were [cyclo-([cyclo-(Glu-Orn-Tyr-Thr-Glu-Ala-Pro- Gln-Tyr-β-amino fatty acid)]. The last two homologues were also differed by a structure of -CH2 and their peptide moiety primary structure were Val (6) instead Ala (6) compared to homologues above. Although the mutant BSFG decreased clearly in antifungal activities, its hemolytic activities showed no obvious difference compared to wild type Bs916. 【Conclusion】This paper reported the cloning, sequencing and characterization of a whole operon Fen which is responsible for synthesis of fengycin. Through bio-information and chemical analysis, the authors confirmed that the fengycin produced by the Bs916 contains five homologues. The fengycin synthesized by Fen plays a crucial part in Bs916 bio-control activities.
    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Response of Soil Enzyme Activity in Different Type of Soils to Cadmium Exposure in China
    KONG Long-1, 2 , TAN Xiang-Ping-1, HE Wen-Xiang-1, 3 , WEI Ge-Hong-2
    Scientia Agricultura Sinica. 2013, 46(24):  5150-5162.  doi:10.3864/j.issn.0578-1752.2013.24.009
    Abstract ( 366 )   PDF (807KB) ( 861 )   Save
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    【Objective】The objective of this study was to clarify the soil enzyme of different type soils affected by Cd under soil environmental quality standards in China, to explore the relationship between soil enzyme and Cd, and discuss the feasibility of soil enzyme acted as an indicator of soil Cd pollution.【Method】The influences of Cd addition to soil enzyme activities in different types of soils were studied by a traditional pot incubation experiment with three Cd concentrations.【Result】The results indicated that the soil acid phosphatase and catalase activity were not sensitive to Cd, Cd could remarkably inhibit soil FDA hydrolase and dehydrogenase activity, but activated the urease and alkaline phosphatase activity. Under the soil environmental quality standards for agricultural soils, the average inhibition rate of soil FDA hydrolase and dehydrogenase was 34.03% and 31.14% respectively. Soil enzymes, soil enzymes-physicochemical properties-Cd information system showed significant positive correlations with soil total enzymatic activities, which suggested they may indicate the Cd contamination.【Conclusion】Soil FDA hydrolase, dehydrogenase and soil total enzymatic activities are sensitive to soil Cd, which can be used as a assisted monitoring indicator. The relationship between soil enzymes and Cd is influenced by many factors such as enzyme types and soil properties, and soil organic matter and pH play a matter role.
    Study on the Balance Between Carbon Source/Sink and Ecological Surplus Using CASA Model in Yulin
    ZHANG Yan-Fang, ZHU Ni
    Scientia Agricultura Sinica. 2013, 46(24):  5163-5172.  doi:10.3864/j.issn.0578-1752.2013.24.010
    Abstract ( 443 )   PDF (4867KB) ( 386 )   Save
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    【Objective】From the perspective of ecological balance, this paper mainly studied the influences and mechanism of carbon source and sink and its ecological effect under the 'Grain for Green Project ' and the key base construction of energy and chemical industry in Yulin so as to provide a scientific basis for reduction of carbon emission and increase of carbon sink.【Method】The estimation and analysis in this paper are based on carbon emission model, CASA model, carbon sequestration and oxygen release model as well as energy consumption statistics, MODIS-NDVI, meteorological data, etc.. 【Result】 Carbon emission of fossil energy consumption increased significantly in Yulin, with a cumulative emission of 8 576.66 104t from 2005 to 2009. Raw coal consumption was the main carbon source. The total carbon emission in Shenmu, Fugu and Yuyang counties accounted for more than 95% of the whole area. The mean value of NPP (net primary productivity, NPP) increased slightly at the average speed of 6 gC•m-2 each year from 2005 to 2009. NPP of Jiaxian, Mizhi and Zizhou counties grew significantly. The mean value of NPP showed a pattern of higher in the south and east, while lower in north and west and the regions which had lower value of NPP centered around Yuyang from northeast to southwest. The amount of CO2 fixed by vegetation was 11 429.3×104 t in Yulin from 2005 to 2009. Overall, the amount of carbon fixation was greater than that of carbon emission in Yulin from 2005 to 2009 and the differences would increase year by year, showing an increasing tendency of ecological surplus levels. Meanwhile, the balance between carbon source and sink and its ecological surplus displayed significant space differences. Shenmu, Fugu and Yuyang counties were the major areas of reducing carbon emission and increasing carbon sink and its ecological surplus level fluctuated significantly and ecological state declined year by year. 【Conclusion】The “Grain for Green Project” would help to increase carbon fixation significantly by vegetation. Increasing the proportion of forest serves as an effective way to increase regional carbon sink, improve regional ecological balance and ease the ecological stress.
    HORTICULTURE
    Evaluation and QTL Mapping for Resistance to Black Spot (Alternaria brassicicola) in Brassica rapa
    CHEN Ying-1, 2 , LIU Li-Wang-1, XIE Xue-Wen-2, MENG Lin-2, LIU Bo-2, WANG Xiao-Wu-2, LI Bao-Ju-2, WU Jian-2
    Scientia Agricultura Sinica. 2013, 46(24):  5173-5179.  doi:10.3864/j.issn.0578-1752.2013.24.011
    Abstract ( 416 )   PDF (534KB) ( 683 )   Save
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    【Objective】The aim of this study is to evaluate Brassica rapa resistance to black spot disease (Alternaria brassicicola), and map QTL related to this trait. The result will provide theoreticalbasis for genetic improvement on resistance to black spot disease in B. rapa crops.【Method】Conidia of A. brassicicola was sprayed to 30-day-old B. rapa seedlings or detached leaves. Disease index was scored after seedlings or detached leaves being kept in dark and wet for three to six days to determine the number of days for inoculation to distinguish the difference in resistance among B. rapa accessions. Using the optimized method, 70 B. rapa accessions were screened for their resistance to black spot disease. Furthermore, a population with 122 recombinant inbred lines (RILs) was used to map QTL for black spot resistance in B. rapa. 【Result】 It was found that inoculation of detached leaves for five days could well distinguish the resistance to black spot disease in B. rapa. Fourteen from 70 B. rapa accessions were identified as resistant to black spot disease. Moreover, we mapped two QTLs related to resistance to black spot in B. rapa, one of which was identified in both two experiments. 【Conclusion】The study showed that different levels of resistance to black spot disease were clearly distinguished when the detached 3rd/4th true leaves of B. rapa being inoculated with A. brassicicola conidia in dark and wet for 5 days. No accession with high resistance to black spot disease was identified in this study. Two QTLs related to resistance to black spot were mapped on chromosomes A05 and A06, respectively.
    Changes of Resistant Starch Content and Correlation with the other Types of Starch in Banana Fruit
    MIAO Hong-Xia-1, JIN Zhi-Qiang-1, 2 , LIU Wei-Xin-1, 3 , ZHANG Jian-Ping-1, SUN Pei-Guang-2, XU Bi-Yu-1
    Scientia Agricultura Sinica. 2013, 46(24):  5180-5187.  doi:10.3864/j.issn.0578-1752.2013.24.012
    Abstract ( 471 )   PDF (480KB) ( 978 )   Save
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    【Objective】The research on resistant starch formation from banana fruit will provide a theoretical basis for practical schemes for breeding cultivars with high starch resistance and improving resistant starch content in banana fruit. 【Method】Banana (Musa acuminata L. AAA group cv. Brazilian) pulp was used to investigate the changes of resistant starch content and correlation with the other types of starch.【Result】The content of total starch, amylose, amylopectin, and resistant starch gradually increased in banana fruit during development, and decreased in banana fruit during postharvest. After treatment with ethylene, the degradation of total starch, amylose, and amylopectin was accelerated; however, the rate of resistant starch degradation was slower than that of the natural ripened (untreated). A single peak was observed for starch content of banana fruit after treatment with 1-methylcyclopropene (1-MCP). Correlation analysis showed that resistant starch formation had a positive correlation with the increase of amylose content. No correlation was found between amylopse and resistant starch content during the development, but resistant starch had a positive correlation with the amylose content; while it had no significant correlation with total starch content after treatment with 1-MCP.【Conclusion】The resistant starch formation is closely related to amylose content. Therefore, regulation of amylose content in banana fruit during the development might promote the formation of resistant starch.
    Study on the Metabolic Pathway of Trehalose in Pleurotus pulmonarius During Heat Stress Recovery
    LIU Xiu-Ming, HUANG Chen-Yang, CHEN Qiang, WU Xiang-Li, ZHANG Jin-Xia
    Scientia Agricultura Sinica. 2013, 46(24):  5188-5195.  doi:10.3864/j.issn.0578-1752.2013.24.013
    Abstract ( 326 )   PDF (466KB) ( 585 )   Save
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    【Objective】 The objective of this study is to explore the recovery mechanism after heat response stress of mushroom, in order to provide a theoretical basis for breeding. 【Method】 The responses of trehalose metabolism at the level of enzyme activity and gene relative expression quantity during heat stress recovery period in two strains of Pleurotus pulmonarius, including the heat sensitive strain CCMSSC 00494 and heat tolerant strain CCMSSC 00499 were investigated. 【Result】The results showed that the trehalose content of two strains rapidly decreased to the control level under heat stress recovery conditions, and the rate of decrease in heat sensitive strain CCMSSC 00494 was faster than that in CCMSSC 00499. During post-heat stress recovery period, trehalose-6-phosphate synthase (TPS) activity of CCMSSC 00494 increased with prolongation of treatment time, while it decreased slowly in CCMSSC 00499. And in both strains, trehalose phosphorylase (TP) activity in the direction of trehalose synthesis decreased suddenly, and TP activity in the direction of trehalose phosphorolysis and neutral trehalase (NTH) activity for trehalose hydrolysis were activated in the early and late period of recovery, respectively. In contrast with the case of tps and tp Genes, the increase of nth mRNA expression was not consistent with the elevation of neutral trehalase activity during heat stress in both strains. 【Conclusion】The main difference between heat sensitive and heat tolerant strains is that the activities and mRNA expression levels of TPS in heat sensitive strain was significantly higher during heat stress recovery period.
    ANIMAL SCIENCE·VETERINARY SCIENCERE·SOURCE INSECT
    Construction of siRNA Expression Plasmids Targeting ChREBP Gene and Its Effect on Lipogenesis in Primary Cultured Porcine Adipocytes
    LU Jian-Xiong, ZHANG Guo-Hua, LI Chang-Hui, CHEN Yan, HUO Sheng-Dong, GUO Peng-Hui, CAI Yong
    Scientia Agricultura Sinica. 2013, 46(24):  5196-5204.  doi:10.3864/j.issn.0578-1752.2013.24.014
    Abstract ( 381 )   PDF (846KB) ( 836 )   Save
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    【Objective】To study the role of ChREBP in the regulation of lipogenesis by glucose in porcine adipocytes, siRNA expression plasmids targeting ChREBP gene were constructed and transfectd into primary cultured porcine adipocytes to silence its expression.【Method】The 4 pairs of oligonucleotides targeting ChREBP gene were synthesized and respectively inserted into linearized pcDNA™6.2-GW/EmGFP vector to construct siRNA expression plasmids. The plasmids were identified by sequencing, and then transfected into the adipocytes from subcutaneous adipose tissue obtained from 3-day-old piglets. Silencing efficiency was determined by fluorescence real-time PCR. The transfected adipocytes were exposed to 0-20 mmol·L-1 glucose for 48 h and lipogenesis and expression of lipogenic genes were measured.【Result】One siRNA expression plasmid with high transfection efficiency and 85% silencing efficiency for ChREBP gene was successfully constructed. Lipogenesis and expression of ACC1 and FAS mRNA were significantly decreased in the transfected adipocytes compared with in negative-siRNA plasmid transfected and non-transfected adipocytes (P<0.05), and the glucose levels had no effect on this decrease of lipogenesis (P>0.05).【Conclusion】The constructed siRNA expression plasmid could effectively interfere ChREBP expression in porcine adipocytes, and ChREBP mediates the regulation of lipogenesis by glucose in the cells.
    Effects of Levels of Dietary Metabolizable Energy and Crude Protein on Growth Performance and Meat Quality of Chinese Yellow Broilers Between 43 and 63 Days
    JIANG Shou-Qun, JIANG Zong-Yong, ZHENG Chun-Tian, LIN Ying-Cai, HONG Ping, CHEN Fang, RUAN Dong
    Scientia Agricultura Sinica. 2013, 46(24):  5205-5216.  doi:10.3864/j.issn.0578-1752.2013.24.015
    Abstract ( 420 )   PDF (633KB) ( 1005 )   Save
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    【Objective】 The effects of levels of dietary metabolizable energy (ME), crude protein (CP) and their interaction on growth performance and meat quality of Chinese yellow broilers between 43 and 63 days were determined. 【Method】 Two dietary ME levels, 11.93 MJ•kg-1 and 12.98 MJ•kg-1, and three dietary CP levels, 14.6%, 15.8% and 17.0%, were examined using a 2 × 3 factorial arrangement of treatments. A total of 840 43-d-old fast-growing Lingnan Yellow male broilers were randomly assigned into 6 treatments, each had four replicates and each replicate had 35 ones. All birds were fed diets with the same ratios of lysine and methionine to CP, and other nutrient levels except ME and CP, and were reared in indoor floor pens with ad libitum access to pellet feed and water for 21 d. 【Result】Birds fed 12.98 compared to 11.93 MJ•kg-1 ME treatment had greater final body weight at 63 d, weight gain, higher pH, breast meat color a* value, lactic acid content of thigh muscle and plasma free fatty acid concentration, and lower FCR, b* value and plasma lipoprotein lipase activity (P<0.05). Diet containing 17% CP decreased FCR and increased breast meat b* value compared to 15.8%, 14.6% treatment (P<0.05), and increased semi-evisecrated percentage and decreased plasma TG content with respect to 14.6% treatment (P<0.05), decreased glutamic acid content in breast muscle compared to 15.8% treatment (P<0.05). There were significant interactions between ME and CP levels on thigh muscle diameter and density (P<0.05), on glutamic acid content (P<0.05) and on plasma free fatty acid content (P<0.05). 【Conclusion】 The optimal dietary ME and CP levels for Lingnan yellow broilers aged between 43 and 63d were 12.98 MJ•kg-1 and 17%, respectively, based on growth performance and carcass traits, and 12.98 MJ•kg-1 and 15.8%, respectively, based on meat quality.
    Establishment of an Experimental Pathological Model by Using EHEC O46 Isolate in Duck
    YU Xue-Hui-1, LI Jian-2, CHENG An-Chun-3, HUANG Zhi-Hong-1, LUO Wei-1, RAN Dan-Dan-1
    Scientia Agricultura Sinica. 2013, 46(24):  5217-5227.  doi:10.3864/j.issn.0578-1752.2013.24.016
    Abstract ( 322 )   PDF (1332KB) ( 543 )   Save
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    【Objective】This experiment was conducted to build an experimental pathological model of EHEC O46 isolate and observe its dynamic distribution, and the dynamic changes of histopathology and ultra-structural pathology in experimentally infected ducklings.【Method】The 10-day-old ducklings were infected with 0.5 mL of O46 isolate(2×108CFU•mL-1)through oral, intramuscular and subcutaneous injection separately. Tissue samples of heart, liver, spleen, lung, kidney, cerebra, esophagus, thymus, duodenum, jejunum, cecum, rectum, bursa of fabricius, pancreas and trachea were taken from the infected ducklings after being infected for 2, 4, 6, 12, and 24 h, and ever since for every 12 hours to make tissue biopsies and ultrathin sections, which were thenstained with haematoxylin and eosin (H.E), as well as uranyl acetate, lead citrate and immunohistochemistry to observe the changes of histopathology, ultra-structural pathology and the bacterial antigen localization in experimentally infected ducklings. 【Result】 Same clinical symptoms as with naturally infected cases were duplicated in experimental pathological model. Bacterial antigens were detected in different tissues except trachea. The target tissues were hearts, lungs, spleens, kidneys and intestinal tracts where bacterial antigen located in cytoplasm and the positive signals were found in heart firstly. Necropsy, histopathological changes and ultra-structural pathological changes showed that main pathological damages of EHEC O46 isolate in ducklings were as follows:serous generalized fibrinous inflammation could be seen; hyperemia, hemorrhage and inflammatory cell infiltration were presented in heart, liver, spleen, lung, kidney, bursa of fabricius, intestinum tenue, pancreas and cerebrum; histopathological changes of necrosis and apoptosis were displayed in parenchyma cell such as renal tubular epithelial cell, hepatocyte, cardiomyocyte and enterocyte; reduction of lymphocytes could be seen in bursa of fabricius. E.coli was observed in heart, lung, spleen, liver, and intestinum tenue by SEM. The target tissue cells where isolate located were lymphocytes, macrophages, enterocytes and cardiac fibroblasts. 【Conclusion】 EHEC O46 isolate in duck showed high pathogenicity in ducklings. Pathologcial changes such as hemorrhagic enteritis and hemolytic uremic syndrome caused by EHEC were duplicated in experimental pathological model. It was concluded that O46 isolate was the pantropic bacteria injuring most tissues and cells in ducklings, and the principal target organs were heart, lung, spleen, kidney and intestine.
    AGRICULTURAL ECONOMY & MANAGMENT
    The Impact of Hybrid Maize Technology Adoption on Farmers’ Livelihoods in Mountains—Evidence from Southwest Yunnan
    WU Hai-Tao, CHEN Yu-Ping, ZHANG Yong-Min
    Scientia Agricultura Sinica. 2013, 46(24):  5228-5236.  doi:10.3864/j.issn.0578-1752.2013.24.017
    Abstract ( 350 )   PDF (526KB) ( 507 )   Save
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    【Objective】 The impact of hybrid maize technology on farmers’ income, livelihood strategy and income disparity was analyzed by employing rural household survey data from mountain regions of Southwest Yunnan. 【Method】Using Feasible Generalized Least Square and Regress-base Decomposition approach, this paper studied the determinants of farmers’ income and livelihoods, and estimated the contribution of adoption of hybrid maize technology to income disparity. 【Result】The adoption of hybrid maize technology had a significant positive effect on farmers’ income. Rural households net income and food crop income increased by 0.5% and 2.5%, respectively, when the area of hybrid maize increased by 1%. The effect of adoption of technology on income inequality was just 0.005. 【Conclusion】In the mountain regions of Southwest Yunnan, hybrid maize technology is an appropriate technology, which can increase farmers’ income and not worsen the income disparity among farmers.
    RESEARCH NOTES
    Preparation of Peanut Oligopeptides from Peanut Protein Isolated by Neutral Proteinase Stepping Hydrolysis
    LI Ning, LIU Hong-Zhi, LIU Li, WANG Qiang
    Scientia Agricultura Sinica. 2013, 46(24):  5237-5247.  doi:10.3864/j.issn.0578-1752.2013.24.018
    Abstract ( 439 )   PDF (600KB) ( 682 )   Save
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    【Objective】The objective of this study is to make full use of the by-products after commercial extraction of peanut oil, and to increase the product additive value, as well as to establish the productive technology of peanut oligopeptides, and finally to put peanut oligopeptides in product of research and development. 【Method】The kind of enzyme, substrate concentration, enzymolysis temperature, enzymatic hydrolysis time on the influence of DH and TCA-NSIwere compared and the best preparation technology was determined by quadratic regression orthogonal rotational combing design. 【Result】 The optimum process parameters for the preparation of peanut oligopeptides from peanut protein isolated by neutral proteinase stepping hydrolysis was that Protamex hydrolyzed continually for 120 min after Neutrase hydrolyzed peanut protein isolated 120 min, the volume of addition of Neutrase was 5 200 U•g-1 substrate and the volume of addition of Protamex was 422.32 U•g-1 substrate, the enzymolysis temperature was 44.83℃, the substrate concentration was 8%. Under these conditions, the TCA-NSI was 83.93%, the DH was 38.25%, and the peanut oligopeptides purity was 93.85%±0.44%. Hydrolysis products with the relative molecular mass less than 1 000 D accounted for 98.88% by HPLC. 【Conclusion】Compared with the existing alkaline protease enzymatic preparation of peanut oligopeptides, the preparation of peanut oligopeptides from peanut protein isolated by Neutrase and Protamex stepping hydrolysis had the characteristics of avoiding subsequent desalting, simplifying process, preparation moderate conditions, high DH, TCA-NSI and purity, and the molecular weight of peptides being mainly concentrated at below 1 000 D.
    Cloning and Expression Analysis of A Soluble Acid Invertase Gene (SoSAI1) of Sugarcane
    NIU Jun-Qi-1, WANG Ai-Qin-1, HUANG Jing-Li-1, ZHU Hui-1, LI Yang-Rui-1, 2 , YANG Li-Tao-1, 2
    Scientia Agricultura Sinica. 2013, 46(24):  5248-5260.  doi:10.3864/j.issn.0578-1752.2013.24.019
    Abstract ( 450 )   PDF (999KB) ( 1038 )   Save
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    【Objective】 The objective of this study is to clone the soluble acid invertase gene (SoSAI1) and 5' promoter sequence from sugarcane, to analyze its sequence and expression patterns. 【Method】 The full-length cDNA sequence of SoSAI1 gene was amplified from the leaves of sugarcane by the technology of rapid amplification of cDNA ends (RACE). The cDNA sequence and the deduced amino acid sequence were analyzed by bioinformatics method. The promoter sequence of SoSAI1 gene was cloned by genome walking. The spatial-specific expressions of SoSAI1 were determined by real-time fluorescent quantitative PCR (qRT-PCR) in leaves and stems at different growth stages of sugarcane, and in roots and leaves under treatment of PEG6000, 100 mmol•L-1 NaCl or 6℃ stress conditions. 【Result】 The cloned full length of SoSAI1 cDNA sequence was 2 387 bp, containing a 2 055 bp open reading frame (ORF) which encodes 685 amino acids with a theoretical molecular mass of 74.44 kD. The 5’ promoter sequence length DNA sequence was 417 bp, which contained endosperm specific expression of cis-acting elements and participate in the drought induced MYB binding sites. The result of real time PCR exhibited that SoSAI1 was the highest abundance in inflorescence and the lowest in old and matured internodes of stems. The conditions of 15% PEG or 6℃ could induce the expression of SoSAI1 gene in leaves, while 15% PEG or NaCl could induce the expression of SoSAI1 gene in roots. 【Conclusion】 The full length of SoSAI1 and part of the promoter were cloned from sugarcane. The analysis by qRT-PCR suggested that SoSAI1 played an important role in sugarcane for growth and development, sucrose accumulation and response to environmental stress.