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Table of Content

    10 August 2009, Volume 42 Issue 8
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
    Genetic Diversity and the Geographical Characteristics of Wild Rice (Oryza rufipogon Griff) in Guangxi
    HUANG Juan,YANG Qing-wen,CHEN Cheng-bin,LIANG Shi-chun,ZHANG Wan-xia,QIAO Wei-hua,WANG Jia-xiang
    Scientia Agricultura Sinica. 2009, 42(8):  2633-2642 .  doi:10.3864/j.issn.0578-1752.2009.08.001
    Abstract ( 1255 )   PDF (439KB) ( 1002 )   Save
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    【Objective】 To estimate the genetic diversity of the populations of wild rice (O. rufipogon Griff) in the whole region of Guangxi Zhuang Autonomous Region and reveal their geographically distribution characteristics. 【Method】 Thirty-six SSR loci distributed on the twelve chromosomes of rice were used to study the genetic diversity of 690 wild rice individuals of 27 natural populations from 14 regions in Guangxi. 【Result】 The mean number of allele (A) was 9.86 and the effective number of allele(Ae) was 5.05. The total genetic diversity (Ht) was 0.74 and the coefficient of genetic differentiation (Gst) was 0.49, which means that the populations of O. rufipogon in Guangxi has abundant genetic diversity and the genetic variability among and between the populations has the same contribution to the total diversity. The analysis of clusters showed that all the samples could be clustered into 3 groups at the coefficient of 0.5, and each group has its own geographic characteristics. 【Conclusion】 O. rufipogon populations in the whole region of Guangxi was not only rich in genetic diversity, but also has close relationship with their geographical conditions like mountains, water systems and geology.

    Cloning of a Sulfite Oxidase Gene and Its Functional Expression in Maize (Zea mays L.) Under SO2 Stress
    XIA Zong-liang,WU Ke,WANG Yong-xia,ZHOU Peng,DING Jun-qiang,WU Jian-yu
    Scientia Agricultura Sinica. 2009, 42(8):  2643-2651 .  doi:10.3864/j.issn.0578-1752.2009.08.002
    Abstract ( 1024 )   PDF (769KB) ( 863 )   Save
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    【Objective】 Sulfite oxidase (SO) plays an important role in sulfur metabolism and sulfur dioxide detoxification in higher plants. To date, most reports on plant SO have focused on Arabidopsis, but little is known about SO in cereal crops such as maize. The objectives of this study are to clone the sulfite oxidase gene and to understand its expression in maize under SO2 stress. This study will provide a basis for genetic improvements in environmental pollutant tolerance (SO2 and acid rain) in maize. 【Method】 The SO gene from maize was cloned by RT-PCR and RACE, and its expression was analyzed under SO2 stress using semi-quantitative RT-PCR method. 【Result】 The full-length sulfite oxidase (SO) cDNA, named ZmSO (GenBank accession number FJ436404), was cloned from an elite inbred Q9. The cDNA contains a 1 194-bp open reading frame (ORF) and encodes 397 amino acids. Sequence alignment and structure prediction showed that the deduced amino acid sequence of ZmSO shared 72%, 74%, and 89% similarities with homologs from other plants such as Arabidopsis thaliana, Lycopersicon esculentum and Oryza sativa, respectively. In addition, similar to other plant SO homologs, ZmSO also contained three conserved functional domains such as one Moco-binding domain, one dimerization domain and one peroxisome targeting signal. Semi-quantitative RT-PCR analysis demonstrated that ZmSO expression was up-regulated significantly in resistant inbred Q9 after treatment with higher concentration of SO2, but not in sensitive inbred Chang7-2. 【Conclusion】 The isolated ZmSO from maize is orthologous to other plant species, and its expression is up-regulated by SO2 stress in the highly resistant line, indicating that the SO from maize may be involved in resistance responses of resistant maize plants to SO2 stress.

    QTL Mapping of Isoflavone, Oil and Protein Content in Soybean
    LIANG Hui-zhen,WANG Shu-feng,YU Yong-liang,LIAN Yun,WANG Ting-feng,WEI Yan-li,GONG Peng-tao,LIU Xue-yi,FANG Xuan-jun
    Scientia Agricultura Sinica. 2009, 42(8):  2652-2660 .  doi:10.3864/j.issn.0578-1752.2009.08.003
    Abstract ( 1061 )   PDF (530KB) ( 996 )   Save
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    【Objective】 Dietary intake of isoflavones has been shown to reduce the risk of several major diseases in humans. Therefore, breeding soybean [Glycine max (L.) Merrill] seeds with desirable isoflavone content would be beneficial to the food and healthy industries, but the environmental sensitivity of the trait complicates phenotypic selection. The objective of this study was to identify quantitative trait loci (QTL) and epistatic interactions associated with isoflavone contents, protein contents, oil contents in soybean seeds. 【Method】 An F13 recombinant inbred line(RIL) comprising 474 lines was derived from a cross between Jindou23 and Huibuzhi. SSR technique was employed for mapping the QTLs. 【Result】 The QTLs for isoflavone content, protein content, oil content were analyzed and 23 QTLs were detected based on the constructed linkage map. Six QTLs for isoflavone content were localized in linkage groups J, N, D2, and G; Eleven QTLs for oil content were localized in the linkage groups A1, A2, B2, C2 and D2. Six QTLs for protein content were localized in linkage groups B2, C2, G and H1. The correlation analysis demonstrated that the content of isoflavone was in significant correlation with protein content. Significantly negative correlations were existed between oil content and protein content, and significantly positive correlations were existed between protein content and the content of total protein and oil. 【Conclusion】 All these have laid an important basis for the marker assisted breeding of the soybean. According to analysis of this investigation, the phenotype correlations of quantitative traits may result from the correlations of QTL controlling those traits.

    Genetic Diversity Among Adzuki Bean Germplasm Revealed by SSR Markers
    WANG Li-xia,CHENG Xu-zhen,WANG Su-hua,XU Ning,LIANG Hui,ZHAO Dan
    Scientia Agricultura Sinica. 2009, 42(8):  2661-2666 .  doi:10.3864/j.issn.0578-1752.2009.08.004
    Abstract ( 1108 )   PDF (269KB) ( 1316 )   Save
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    【Objective】 Adzuki bean originated from China, and there are abundant germplasm in China. Evaluation of the genetic diversity can accelerate the application of them in breeding program. 【Method】 In this study, 51 pairs of SSR primers were used to assess the genetic diversity and structure among 137 Chinese and eight alien adzuki bean germplasm. 【Results】 A total of 222 alleles were detected and the alleles with frequency lower than 5% accounted for about 35.9%. The number of alleles changed from 2 to 13 with an average of 4.35 per locus. The PIC value varied from 0.014 to 0.838, and the mean PIC value for SSRs on each linkage group was 0.440. The similarity coefficient between accessions varied from 0.227 to 0.951 and averaged at 0.487. Adzuki bean from Hubei and Shaanxi provinces had much higher genetic variations, and their genetic backgrounds are much different from that of other provinces. Cluster analysis divided the 145 accessions into five groups, which is much agreeable with that obtained in analysis by using STRUCTURE package, and the accessions within five groups almost related with their origins of geographical distribution. 【Conclusion】 There are abundant genetic variations in Chinese adzuki bean. The genetic differentiation among adzuki bean from different origins is important in dividing ecological region for Chinese adzuki bean.

    Principal Component Analysis and Fuzzy Clustering on Drought-Tolerance Related Traits of Foxtail Millet (Setaria italica)
    MENG Qing-li,GUAN Zhou-bo,FENG Bai-li,CHAI Yan,HU Yin-gang
    Scientia Agricultura Sinica. 2009, 42(8):  2667-2675 .  doi:10.3864/j.issn.0578-1752.2009.08.005
    Abstract ( 1165 )   PDF (271KB) ( 1562 )   Save
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    【Objective】 The main purpose of this paper was to explore the methods of drought tolerance evaluation, and to evaluate the relationships between some agronomic traits and physiological indicators with drought-tolerance in foxtail millet (Setaria italica). 【Method】 Principal Component Analysis (PCA) and Fuzzy Clustering (FC) were used to evaluate the drought tolerance of 16 foxtail millet cultivars based on their performance under the conditions of rainfed and water limited cultivation under rainout shelter. 【Result】 The result of Principal Component Analysis indicated that 6 principal components could present 90.71% information of the raw data of the traits related to drought tolerance of foxtail millet. The 16 cultivars used in this study could be divided into 3 clusters by Fuzzy Clustering based on their Drought-tolerance Value (DV), which could reflect the drought characteristics of the origins and planting areas of those cultivars. Among those cultivars,the drought tolerance of Jigu18 and Yugu1 were better and more stable. 【Concussion】 It is an effective way to comprehensively evaluate the drought tolerance of foxtail millet by Principal Component Analysis and Fuzzy Clustering,which not only could avoid the bias and the instability of single factor analysis, but also reflect the relationship between different drought tolerance related traits and drought tolerance in foxtail millet better.

    Cloning and Expression Analysis of a Water Stress-Induced ALDH Gene from Sugarcane
    ZHANG Ji-sen,GUO Chun-fang,WANG Bing-mei,ZHANG Mu-qing,CHEN You-qiang,CHEN Ru-kai
    Scientia Agricultura Sinica. 2009, 42(8):  2676-2685 .  doi:10.3864/j.issn.0578-1752.2009.08.006
    Abstract ( 1046 )   PDF (876KB) ( 1035 )   Save
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    【Objective】 In this study, the objective is to screen and clone the drought stress resistance-related genes, and analyze the expression pattern of those genes which aim to probe into the molecular mechanism of drought resistance and provide candidate genes for drought-resistance plant breeding. 【Method】 Combining SSH and cDNA microarray to screen of up-regulated ESTs in the water stress Erianthus arundinaceus based on the analysis of up-regulated ESTs, a full-length cDNA sequence was cloned from sugarcane through Rapid Amplification of cDNA Ends (RACE) method, and the gene expression character was analyzed by real time RT-PCR. 【Result】 Four obvious up-regulated ESTs of SSADH were obtained in the drought stress Erianthus arundinaceus througth cDNA microarray hybridization. The full-length cDNA of SSADH termed as sc-SSADH from sugarcane was 1 914 bp in length, contains a 1 581 bp open reading frame (ORF) encoding a 527 amino acid protein, with 25 bp in the 5′ UTR and 306 bp in the 3′ UTR, including a poly (A) signal at 1 749 position. GenBank Blast analysis showed that SSADH was 73% identical to Arabidopsis thaliana SSADH (NM_106592.3). Real time RT-PCR analysis revealed that the sc-SSADH was a whole range PEG-stress responsive gene, and it could also be regulated by Ca2+ in sugarcane. 【Conclusion】 It is the first report of the cloning and expression analysis of SSADH in sugarcane, and the sc-SSADH is a dehydration-responsive gene. At the same time, Ca2+ has been proposed to play a role in the regulation of SSADH

    A Rank-Sum Testing Method for Multi-Trait Comprehensive Ranking and Its Application

    LUO Ru-jiu,HU Zhi-qiu,SONG Wen,XU Chen-wu
    Scientia Agricultura Sinica. 2009, 42(8):  2686-2694 .  doi:10.3864/j.issn.0578-1752.2009.08.007
    Abstract ( 967 )   PDF (520KB) ( 762 )   Save
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    【Objective】 The rank-sum test is a nonparametric method used in variety evaluation. However, the hypothesis testing theory of this method hasn’t been established for multi-trait comprehensive ranking. 【Method】 In this paper, under null hypothesis: the variety’s ranking on each trait is random. 【Result】 The theoretical distribution of sum of ranks (SR) was firstly derived and further used to obtain the critical values for multi-trait comprehensive evaluation in rank-sum test. A new C++ class and its basic arithmetic were defined to deal with the miscount caused by the precision limitation of built-in data type in common statistical software under large number of varieties and traits. Finally, an application of the theoretical results was demonstrated using five starch viscosity traits of 12 glutinous maize varieties. 【Conclusion】 The proposed method is so simple and convenient that it can be easily used to rank different varieties by multiple traits.

    TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY
    A New Spectral Index for Estimating Protein Nitrogen Concentrations in Top Leaves of Rice
    YANG Jie,TIAN Yong-chao,ZHU Yan,CHEN Qing-chun,YAO Xia,CAO Wei-xing
    Scientia Agricultura Sinica. 2009, 42(8):  2695-2705 .  doi:10.3864/j.issn.0578-1752.2009.08.008
    Abstract ( 1027 )   PDF (563KB) ( 895 )   Save
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    【Objective】 The objectives of this study were to analyze the relationships between leaf protein nitrogen concentrations (LPNC) and spectral reflectance characteristics, and to establish useful hyperspectral bands and hyperspectral indices for nondestructive and quick assessment of LPNC in top leaves of rice (Oryza sativa L.). 【Method】 Three field experiments were conducted with different N rates and rice cultivars. Time-course measurements were taken on hyperspectral reflectance of 350-2 500 nm and LPNC in four top leaves. Statistical analyses were made on the relationships between LPNC and reflectance indicators such as simple ratio indices (SR[λ1, λ2]) and normalized difference spectral index (ND[λ1,λ2]) using all combinations of two wavelengths (λ1 and λ2 nm) and other existing indices. 【Result】 The results indicated that the LPNC in rice and spectral reflectance varied distinctly with nitrogen rates, growth stages and leaf positions. The sensitivity bands mostly occurred 530-580 nm within green light region and 695-715 nm within red edge region, and a close correlation existed between red-edge district and LPNC. The SR indices composed of reflectance around 700 nm and near infrared short wavelengths were significantly correlated with LPNC, next came the 587 nm. A new spectral index SR (770,700) and existing indices GM-2, SR705, RI-half were found to be good indicators for LPNC, and linear regression models were established with determination of coefficients (R2) as 0.874, 0.873, 0.871 and 0.867, respectively. Tests with other independent datasets showed that the models based on those key spectral indices could be used to predict LPNC reliably. 【Conclusion】 It can be concluded that the LPNC in rice could be monitored directly by key spectral indices, such as SR (770, 700), GM-2, SR705 and RI-half.

    Comparison of Starch Accumulation and Sink Strength in Superior and Inferior Grains Between Compact and Loose Spike Wheat Cultivars

    YAN Su-hui,YIN Yan-ping,LI Wen-yang,LI Yong,SUI Xin-xia,GU Feng,LIANG Tai-bo,ZHANG Ti bin,WANG Ping,WANG Zhen-lin
    Scientia Agricultura Sinica. 2009, 42(8):  2706-2715 .  doi:10.3864/j.issn.0578-1752.2009.08.009
    Abstract ( 1182 )   PDF (404KB) ( 832 )   Save
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    【Objective】 The objectives of this study were to elucidate the relationship between starch accumulation and grain sink strength in superior and inferior grains of wheat, and to characterize the variance between the compact and loose spike cultivars in the starch accumulation and grain sink strength in superior and inferior grains. 【Method】 The field experiments were carried out at Tai’an Experimental Station of Shandong Agricultural University in two growing seasons from October 2005 to June 2006 and from October 2006 to June 2007. Two loose spike wheat cultivars, SN1391 and SN12, and two compact spike wheat cultivars, LM21and JM20, were chosen in this study. Heads flowering on the same date were labeled with red thread after full heading. Spikes were sampled at 5-day intervals after anthesis till maturity, and partitioned into two groups, superior grains (the 1st and 2nd grains from the basal part of middle spikelets) and inferior grains (the 3st and 4nd grains from the basal part of middle spikelets). The starch composition accumulation, endosperm cell numbers and activities of enzymes involved in starch synthesis were examined during grain development of winter wheat. 【Result】 The results showed that the accumulation of amylose and amylopectin in superior grains were significantly higher than those in inferior grains in both spike type cultivars. But the magnitude of difference in amylose and amylopectin accumulation between superior and inferior grains in compact spike wheat cultivars was large as compared with that in loose spike wheat cultivars. The accumulation courses of starch were well fitted to the logistic equation by relating starch contents against days after anthesis. Logistic simulation revealed that the higher starch accumulation in superior grains resulted from earlier initiating accumulation time and greater accumulation rate. There was a larger difference in starch accumulation rates between superior and inferior grains in compact spike wheat cultivars as compared with that in loose spike wheat cultivars, which may be one of the reasons that caused larger difference in starch accumulation between superior and inferior grains in compact spike wheat cultivars. Endosperm cell numbers in superior grains were significantly higher than those in inferior grains. The magnitude of difference in endosperm cell numbers between superior and inferior grains varied with cultivars, the greater difference was detected in compact spike cultivars, whereas smaller in loose spike cultivars. The sucrose content in superior grains was lower than those in inferior grains during grain filling, which indicated that the sucrose content (substrate of starch synthesis) may not be a main limiting factor for starch synthesis in inferior grain. The activities of enzymes involved in starch synthesis including sucrose synthase (SS), adenosine diphosphorate glucose pyrophosphorylase (AGPP), soluble starch synthase (SSS) and granule-bound starch synthase (GBSS) in superior grain were significantly higher than those in inferior grains. The magnitude of difference in the above indexes between superior and inferior grains was larger in compact spike cultivars than that in loose spike cultivars. 【Conclusion】 The results here suggested that grain sink strength, determined by both endosperm cell numbers and activities of enzymes involved in starch synthesis, is the main factor responsible for starch accumulation in wheat grain. The larger difference in the grain sink strength was found to result in larger difference in starch accumulation between superior and inferior grain in compact spike cultivars as compared with loose spike cultivars.

    Research of the Optimum Hyperspectral Vegetation Indices on Monitoring the Nitrogen Content in Wheat Leaves

    YAO Xia,ZHU Yan,TIAN Yong-chao,FENG Wei,CAO Wei-xing

    Scientia Agricultura Sinica. 2009, 42(8):  2716-2725 .  doi:10.3864/j.issn.0578-1752.2009.08.010
    Abstract ( 1350 )   PDF (470KB) ( 909 )   Save
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    【Objective】 Crop nitrogen status is an important index for evaluating the growth status and forecasting grain yield. Non-destructive and fast monitoring of leaf nitrogen status can play a significant role in precision nitrogen management in wheat production. The primary objective of this study was to explore the optimum wavebands, vegetation indices and quantitative models for estimating leaf nitrogen content (LNC) in wheat by precise analysis on canopy hyperspectral information in relation to leaf nitrogen status. 【Method】 On the basis of detailed data from 4-year field experiments under varied nitrogen rates and wheat cultivars, a systematic analysis was undertaken on quantitative relationships of LNCs to major hyperspectral indices composed of any two wavebands with original reflectance and its derivative within the full spectral range of 350-2 500 nm. 【Result】 The results showed that the optimum wavebands for LNC were 690 nm, 691 nm, 700 nm and 711 nm in the red edge range, and 1350 nm in the near-infrared range. The derived key hyperspectral parameters were NDSI (R1350, R700) and NDSI (FD700, FD690) as Normalized Difference Spectral Index, RSI (R700, R1350) and RSI (FD691, FD711) as Ratio Spectral Index, and SAVI (R1350, R700)(L=0.09) and SAVI (FD700, FD690)(L=-0.01) as Soil Adjusted Spectral Index. The LNC monitoring models developed from these spectral indices gave the coefficients of determination (R2) no less than 0.842. Testing of the derived equations with independent experiment data produced R2 values over 0.758 and RRMSE lower than 0.266, with best performance from the model based on RSI (FD691, FD711) and SAVI (FD700, FD690)(L=-0.01). 【Conclusion】 Overall, the method of discovering the optimum bands and constructing the spectra indices and building the model based on the systematic precise analysis methods can enhance the precision and reliability of the N monitoring model, and provide new waveband choice and technical approach for non-destructive and fast monitoring of the canopy nitrogen status in wheat.

    The Role of Jasmonic Acid in the Systemic Induced Defense Response of Aboveground and Underground in Corn (Zea mays)
    FENG Yuan-jiao,WANG Jian-wu,SU Yi-juan,LUO Shi-ming
    Scientia Agricultura Sinica. 2009, 42(8):  2726-2735 .  doi:10.3864/j.issn.0578-1752.2009.08.011
    Abstract ( 1247 )   PDF (477KB) ( 1151 )   Save
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    【Objective】 The objective of this investigation was to study whether exogenous jasmonic acid treatment to the aboveground (or underground) could systemically affect the defense response of underground (or aboveground) in corn, and to find out whether the effect of defense response was related with the signal transduction of jasmonic acid. 【Method】 Both chemical analysis and gene expression analysis were employed to study the role of jasmonic acid on the induced defense response of aboveground and underground in corn cultivar Gaoyou 115 by comparative studies prior to using the inhibitor salicylhydroxamic acid (SHAM) in jasmonic acid signaling pathway. 【Result】 The results showed that exogenous jasmonic acid applied to the aboveground of corn could systemically affect the content of defense chemicals and the expression of defense-related genes of underground, and vice versa. Jasmonic acid treatment to either aboveground or underground could result in much more obvious defense response in the leaves as compared to the roots, while jasmonic acid treatment to the aboveground could lead to much stronger induction in the same parts of corn than to the underground. Through activating the synthesis of jasmonic acid itself, aboveground application of jasmonia acid could induce the expression of Bx1, Bx9, PAL, PR-1, MPI, FPS and TPS genes, increase DIMBOA content and decrease caffeic acid content in leaves; on the other hand, the systematic induction of gene expression of Bx6, Bx9、PAL and PR-2a, increase of contents of coumaric acid and caffeic acid, and decrease of syringic acid content in the roots were related with the activating of jasmonic acid synthesis in the aboveground. Likewise, after the underground of corn was treated with jasmonic acid, the induced expression of Bx6, PR-2a and MPI genes as well as the decrease of total phenolics in the roots were achieved through activating the synthesis of jasmonic acid itself; while the indirect induction of expression of Bx6, Bx9, PAL, FPS and TPS genes as well as the increase in the contents of DIMBOA, coumaric acid, caffeic acid, and syringic acid in the leaves were related with the activating of jasmonic acid synthesis in the underground. 【Conclusion】 These findings indicate that exogenous jamonic acid application to the aboveground can systematically affect the defense response in the underground of corn, and vice versa. Leaves show much stronger induced defense to jasmonic acid application than roots. Application of jasmonic acid to the aboveground of corn has stronger induction than to the underground. The effects of jasmonic acid treatment to aboveground or underground on the defense response in treated parts of corn are acquired mainly by activating the synthesis of corn internal jasmonic acid, and the effects on the defense response in non-treated parts are related with the activating of jasmonic acid synthesis in the treated parts.

    Effects of Wheat-Residue Application and Site-Specific Nitrogen Management on Grain Yield and Quality and Nitrogen Use Efficiency in Direct-Seeding Rice
    XU Guo-wei,TAN Gui-lu,WANG Zhi-qin,LIU Li-jun,YANG Jian-chang
    Scientia Agricultura Sinica. 2009, 42(8):  2736-2746 .  doi:10.3864/j.issn.0578-1752.2009.08.012
    Abstract ( 1077 )   PDF (329KB) ( 1523 )   Save
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    【Objective】 The purpose of this study was to investigate the effects of wheat-residue application and nitrogen (N) management on grain yield and quality and nitrogen use efficiency in direct-seeding rice. 【Method】 A mid-season japonica rice cultivar of Yangjing 9538 was directly sown in the field. Three treatments of N-fertilizer application, farmers’ N-fertilizer practice (FFP), site-specific N management (SSNM) based on chlorophyll measurement (SPAD) readings, and no N application, and with or without wheat residue application were conducted. Grain yield and quality and N use efficiency were determined. 【Result】In comparison with the wheat-residue removal treatment, the wheat-residue application (the residue was incorporated into soil) treatment reduced panicles, but increased spikelets per panicle, filled-grain percentages and 1 000-grain weight, therefore increased grain yield. This treatment also improved rice appearance and cooking qualities, under either SSNM or FFP. In comparison with FFP, SSNM increased grain yield, reduced the grain protein content, and improved rice cooking quality. In comparison with the wheat-residue removal plus FFP treatments, the wheat-residue application plus SSNM treatments enhanced the maximum grain filling rate and mean grain filling rate and shortened the active grain filling period, leading to an increase in grain weight. Such treatments increased N harvest index, N recovery efficiency, N agronomic use efficiency, N physiological efficiency, and N partial factor productivity. 【Conclusion】 The results suggest that wheat-residue application combined with SSNM could not only increase grain yield and quality, but also improve N use efficiency in direct-seeding rice.

    Characteristics of Soil Temperature and Its Response to Air Temperature Under Different Tillage Systems —— Characteristics of Soil Temperature and Thermal Properties
    CHEN Ji-kang,ZHANG Yu,CHEN Jun-sheng,CHEN Fu,ZHANG Hai-lin
    Scientia Agricultura Sinica. 2009, 42(8):  2747-2753 .  doi:10.3864/j.issn.0578-1752.2009.08.013
    Abstract ( 1439 )   PDF (305KB) ( 867 )   Save
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    【Objective】 Field experiment was conducted to study the effects of tillage on soil temperature and soil thermal properties in winter wheat field. 【Method】 Conventional tillage (CT), rotary tillage (RT) and no tillage with stubble covering (NT) were used from 2004 to 2005 at Luancheng Station of Hebei Province. Soil temperature and thermal properties were measured by thermo-time domain reflectometry. Combining with the growth and development course of winter wheat, tillage effects were discussed. 【Result】 Results showed that the tillage effects on soil temperature were mainly occurred before jointing stage of winter wheat. Compared with CT and RT, NT showed a “higher temperature effect” when temperature was dropping and a “lower temperature effect” when temperature was warming up, significantly. Diurnal average soil temperature was 0.69-1.02 ℃ lower, the seedling and tillering was delayed by 2 and 7 d, tillering time before over-wintering was decreased by 9 d, and the active accumulated temperature was decreased by 54.12-55.55℃?d under NT. During over-wintering stage, NT showed a higher average soil temperature (0.02-0.09℃) and negative accumulated temperature 0.87-2.25℃?d, but the day steadily pass 0℃ was delayed by 7 d, low temperature duration was 2-3 d longer and the revival stage was delayed by 2-6 d. Winter wheat under NT needed more active accumulated temperature 21.54-29.15℃ to complete revival and the jointing stage was delayed by 5 d. The accumulated and diurnal mean temperature difference was decreased by 123.43-148.62℃ and 1.17-1.42℃ under NT, respectively. Compared with CT, the revival was delayed by 4 d, the active accumulated temperature was decreased by 8.55 ℃, and the accumulated temperature difference was increased by 25.19℃. It showed no significant difference of ρc, λ, and α between different tillage systems. 【Conclusion】 In terms of the course of winter wheat, heat use efficiency was the highest under CT and the lowest under NT and the medium under RT. The lower temperature under NT was not beneficial to the growth and development of winter wheat, but beneficial to safe over-wintering. The temperature effects of NT were mainly controlled by stubble covering but not the soil thermal properties.

    PLANT PROTECTION
    A Preliminary Study of the Putative Glycosyl Hydrolase Family 62 in Magnaporthe grisea
    ZHOU Jie,ZHENG Xiang-zi,LAN Lan,LIN Cheng-zeng,LIN Xiong-jie,LU Guo-dong,WANG Zong-hua
    Scientia Agricultura Sinica. 2009, 42(8):  2754-2762 .  doi:10.3864/j.issn.0578-1752.2009.08.014
    Abstract ( 1025 )   PDF (897KB) ( 765 )   Save
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    【Objective】 Glycosyl hydrolase family 62 encode putative alpha-L-arabinofuranosidases, a group of cell-wall degrading enzymes which may involve in the fungal pathogenesis. To better understand the role of cell-wall degrading enzymes in pathogenesis, the putative glycosyl hydrolase family 62 in Magnaporthe grisea we characterized in this study. 【Method】 The bioinformatics tools were firstly used to analyze putative members in the annotated glycosyl hydrolase family 62, including their gene structure, protein secretion characters, and conduct a phylogenetic analysis. Then overexpression and knockout techniques were applied to further study the function of MGG_01403.6, one of the 8 members in the family. 【Result】 The result showed that all the members are secreted proteins with cell-wall degrading enzyme (Glycosyl hydrolase family 62) domain. Phylogenetic analysis showed that 8 members of glycosyl hydrolase family 62 of the fungus could be classified into 2 clusters. Gene expression showed difference among family members after fungal infection. But gene knockout and overexpression of MGG_01403.6 had no effect on the fungal pathogenicity. 【Conclusion】 Functional redundancy may exist in glycosyl hydrolase family 62 members from Magnaporthe grisea. The double or multiple deletions are necessary for further characterization of the function of this multi-gene family.

    SSR Analysis of Population Genetic Diversity of Puccinia striiformis f.sp.tritici in Longnan Region of Gansu,China
    LU Ning-hai,ZHENG Wen-ming,WANG Jian-feng,ZHAN Gang-ming,HUANG Li-li,KANG Zhen-sheng
    Scientia Agricultura Sinica. 2009, 42(8):  2763-2770 .  doi:10.3864/j.issn.0578-1752.2009.08.015
    Abstract ( 1037 )   PDF (336KB) ( 1105 )   Save
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    【Objective】 As Longnan region of Gansu province is one of the largest and most important over-summering areas of Puccinia striiformis f. sp. tritici in China, the objective of this study is to determine the genetic structure of P. striiformis f. sp. tritici populations in this region. 【Method】 Population genetic diversity of the P. striiformis f.sp. tritici population containing 409 isolates collected from 8 different areas in Longnan, Gansu province was investigated with TP-M13-SSR technique. 【Result】 For the Longnan population, the average number of alleles (Na) per locus was 1.95, and the effective number of alleles (Ne) was 1.43. The Nei's gene diversity (H) and Shannon's information index (I) were 0.27 and 0.41, respectively. The genetic diversity of Wudu, Wenxian and Qingcheng populations was much higher than that of Huixian, Chengxian and Xihe populations. Analysis of AMOVA showed that there were about 12.5% of the total variations among the collections, 87.5% of the total variation presented within collections. Gen flow (Nm) was 1.83. 【Conclusion】 The important conclusion is that the populations of P. striifornis f. sp. tritici possessed relatively high levels of genetic diversity but a lower genetic differentiation in Longnan of Gansu. The main genetic variation presented within collections. There is an extensive gene flow and migration of pathogen among the regions in Longnan of Gansu.

    Molecular Marker Mapping and Genetic Analysis of a Novel Powdery Mildew Resistance Gene PmHNK
    LI Chun-xin,XU Wei-gang,WANG Gen-song,HU Lin,ZHANG Lei,ZHANG Jian-zhou,DONG Hai-bin
    Scientia Agricultura Sinica. 2009, 42(8):  2771-2777 .  doi:10.3864/j.issn.0578-1752.2009.08.016
    Abstract ( 1071 )   PDF (415KB) ( 1035 )   Save
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    【Objective】 Powdery mildew is one of the most important diseases of wheat worldwide. Zhou 98165, a winter wheat provided by wheat research center of Henan Academy of Agricultural Sciences, is a novel line which has highly resistant, high yield and excellent comprehensive agricultural characteristics. Inheritance of powdery mildew resistance gene and mapping of that in Zhou 98165 with simple sequence repeat (SSR) markers were studied to formulate efficient resistance gene and strategies for breeding cultivars resistant to powdery mildew. 【Method】 F1, F2, BC1 populations were constructed on the basis of the hybridization between Zhou 98165 and a susceptible wheat variety Chinese Spring. Powdery mildew strains LY2-1, ZZ1-1 and 02B1 were used for the test the resistance and genetic analysis of those populations with the SSR and EST-SSR primers. The location of this gene on chromosome was confirmed by the materials of monosomic CS. 【Result】 Genetic analysis of Zhou 98165 indicated that the resistance to powdery mildew race 08B1 was controlled by a single dominant karyon gene, temporarily designated as PmHNK. Five SSR markers , Xbarc77, Xgwm547, Xwmc 326,Xgwm299, and Xgwm108 were linked to PmHNK as they were all located on chromosome 3BL. PmHNK, located on 3BL,closely linked to Xgwm299 and Xgwm108 with genetic distances of 4.2 cM and 5.6 cM, respectively.The farthest marker Xbarc77 was 10.6 cM to PmHNK. 【Conclusion】 Genetic analysis and resistance identification with powdery mildew isolates to Zhou98165 combined with SSR markers supports the conclusion that the highly resistance gene PmHNK is a novel gene for powdery mildew in wheat.

    Differential Proteomics Analysis of the Responses of Resistant Gene Pm21 to Wheat Powdery Mildew
    LI Qiang,ZHANG Wei-dong,TIAN Ji-chun
    Scientia Agricultura Sinica. 2009, 42(8):  2778-2783 .  doi:10.3864/j.issn.0578-1752.2009.08.017
    Abstract ( 1212 )   PDF (409KB) ( 887 )   Save
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    【Objective】 In order to understand differential expression proteins in the response to wheat powder mildew between two near-isogenic wheat lines, BAINONG 3217, which is susceptive to wheat powder mildew, and W2132-6, which carrys resistance gene Pm21 and is resistant to wheat powder mildew. 【Method】 Differential proteomics between the two lines were studied after they were infected by Blumeria graminis. Protein samples were respectively extracted from the leaves after 48 h inoculation, separated by two-dimensional electrophoresis, dyed by CBB, and were identified by MALDI-TOF-MS. 【Result】 It was found that there were twelve protein spots expressed differentially, and nine of them were identified by MALDI-TOF-MS and database searching. The predicted function of seven proteins were related to energy metabolism, signal control, defensive responses and proteins stabilization, which were involved in many resistant physiological reactions, including enhancing energy metabolism, signal control, antioxidant reaction, cell-wall reinforcement and lignification. 【Conclusion】 The response to powder mildew was changed by Pm21. Stress response proteins (e.g. proline-rich family protein) should be related with resistance to wheat power mildew.

    Inhibitory Effect and Antimicrobial Mechanism of Pyrolin on Monilinia fructicola in Peach
    WU Zhen-yu,WANG Yan,AI Qi-jun
    Scientia Agricultura Sinica. 2009, 42(8):  2784-2792 .  doi:10.3864/j.issn.0578-1752.2009.08.018
    Abstract ( 1103 )   PDF (705KB) ( 899 )   Save
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    【Objective】 To explore the antifungal activity and potential mechanism of pyrolin against Monilinia fructicola. 【Method】 Agar plate tests was conducted to test the inhibitory effect in-vitro and in vivo of pyrolin. And doubling dilution method was used to determine the minimal inhibitory concentration (MIC) and minimal fugicide concentration (MFC). Polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonium-lyase (PAL) activities induced by inoculation with pyrolin and M. fructicola were studied in peach. The ultrastructure of M. fructicola treated by pyrolin was observed through scanning electron microscope (SEM) and transmission electron microscope (TEM). 【Result】 Pyrolin displayed strong antifungal activity to M. fructicola and the activity was significantly increased when the applied concentration was higher, the MIC value of 0.032 mg?mL-1 and MFC value of 0.156 mg?mL-1. The activities of PPO, POD and PAL in peach increased significantly when inoculated with pyrolin and M. fructicola, and maintained at a high level throughout the experiment. The observations with SEM revealed that the hyphae distorted, the adhesions mycelium occurred, the cell wall was rupture, cell surface occurred substance of flocculent agglutination. The observations with TEM showed that the hypha became thinning obviously, the inner structure confused, the hyphal cell was damaged severely. 【Conclusion】 Pyrolin has a strong antifungal activity and exerts a potent impact on the ultrastructure of M. fructicola.

    Acaricidal Activity of an Extract of Pharbitis purpurea seeds Against Tetranychus cinnabarinus
    WANG Yan,WU Zhen-yu,DU Yan-li,SHI Guang-lu,CHEN Mei,WANG Hai-xiang,WANG You-nian
    Scientia Agricultura Sinica. 2009, 42(8):  2793-2800 .  doi:10.3864/j.issn.0578-1752.2009.08.019
    Abstract ( 1078 )   PDF (646KB) ( 793 )   Save
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    【Objective】 The activity of fraction 8 from the petroleum ether extract of Pharbitis purpurea seeds was investigated against Tetranychus cinnabarinus. 【Method】 The acaricidic activity of fraction 8 was measured with the methods of slide dip and leaf residue, and several enzymes in T. cinnabarinus treated with isolation fraction 8 were examined. The ultrastructure of the treated mites was observed by using transmission electron microscope (TEM). 【Result】 The tested fraction showed lethal effects on the mite adults and eggs with the LC50s of 0.4686 and 1.2212 mg/ml and the LC90s of 2.5935 and 3.1234 mg/ml, respectively. Glutathione-S-transferase activity was strongly induced in treated mites whereas acetylcholinease, monoamine oxidase and Ca2+-ATPase were suppressed in activity after treatment. The results indicated that the extracted fraction of P. purpurea seeds was acaricidal, perhaps attributing to neural transmit block in treated mites. TEM observations revealed that the treated mites suffered from the ruptures of cuticle, muscular filament, nuclear membrane, mitochondria and endoplasmic reticulum. 【Conclusion】 Thus, P. purpurea seeds can be exploited as new resources for developing potential acaricides.

    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Short-Term Impacts of No Tillage on Soil Organic Carbon Associated with Water-Stable Aggregates in Black Soil of Northeast China
    LIANG Ai-zhen,YANG Xue-ming,ZHANG Xiao-ping,SHEN Yan,SHI Xiu-huan,FAN Ru-qin,FANG Hua-jun
    Scientia Agricultura Sinica. 2009, 42(8):  2801-2808 .  doi:10.3864/j.issn.0578-1752.2009.08.020
    Abstract ( 970 )   PDF (511KB) ( 766 )   Save
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    【Objective】 In order to get a good indicator to evaluate the impacts of no tillage (NT) on soil structure and soil quality, the dynamics of total soil organic carbon (SOC) and SOC associated with aggregates, and the relationships between total SOC and aggregate-associated SOC in the plow layer (30 cm) in black soil in Northeast China under NT practice were sludied. 【Method】 The tillage experiment was established in Dehui County, Jilin Province in 2001. The total SOC and aggregate-associated SOC in 5-year tillage treatments were measured. 【Result】 NT practices did not lead to increase of average SOC content at 0-30 cm depth, but it did significantly increase SOC at the top soil (0-5 cm). In NT plot, the change trend of SOC in >1 000 μm aggregate was the same with that of total SOC, but the effect of NT on SOC in >1 000 μm aggregate was greater than the effect on total SOC, suggesting that >1 000 μm aggregate had more sensitive response to the impact of tillage practices. Significant positive correlation occurred between total SOC and SOC in >1 000 μm aggregate in black soil. 【Conclusion】 In the short term soil macroaggregate >1 000 μm could be used as an indicator to evaluate the impacts of tillage practices on soil structure and soil fertility in black soil in Northeast China.

    Effects of Organic Manure and Fertilizers Long-Term Located Application on Soil Fertility and Crop Yield
    LIN Zhi-an,ZHAO Bing-qiang,YUAN Liang,Hwat Bing-So
    Scientia Agricultura Sinica. 2009, 42(8):  2809-2819 .  doi:10.3864/j.issn.0578-1752.2009.08.021
    Abstract ( 1088 )   PDF (405KB) ( 1377 )   Save
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    【Objective】 To evaluate the effect of organic manure and fertilizers long-term located application on soil nutrients and crop yield. 【Method】 The results of crop yields and soil nutrients were measured and collected based on a 22-year long-term located application of organic manure and fertilizers experiment in Yucheng city of Shandong Province. 【Result】 The effect of chemical fertilizers on winter wheat yield was better than organic manure during the first 8-10 years, but the reverse result was observed in summer maize yield. The combined effect of chemical fertilizers with organic manure on wheat and maize yields was very obvious. However, with prolonged application, the yields of each treatment, no matter with organic manure or chemical fertilizer or combined, turned out similar. Soil organic matter content increased with time and application level of organic manure during the 22 years. Soil organic matter and total nitrogen contents were found unrelated to the application rate of chemical fertilizers in this long-term experiment. Increased application of chemical fertilizer could enhance soil available nutrient contents and at the same time be kept relatively stable to some extent. 【Conclusion】 The effect of chemical fertilizer on winter wheat yield was better than organic manure during the first 10 years, however, a reverse result was observed in summer maize yield, and after that the crop yields of all treatments were found similar. Therefore, increased application of fertilizer did not improve the crop yield. The effect of organic manure on soil organic C and N content increase was much better than chemical fertilizer, and the soil organic C and N content increased with the application rate of organic manure. Soil organic C and N content could not be improved by application increase of chemical fertilizer. With prolonged application, organic manure could improve soil available nutrients content continually, and its effect was found much obvious than that of chemical fertilizer.

    Effects of Long-Term Fertilization on Organic Nitrogen Forms and Their Distribution in Profile of a Brown Soil
    GAO Xiao-ning,HAN Xiao-ri,LIU Ning,ZUO Ren-hui,WU Zheng-chao,YANG Jin-feng
    Scientia Agricultura Sinica. 2009, 42(8):  2820-2827 .  doi:10.3864/j.issn.0578-1752.2009.08.022
    Abstract ( 1072 )   PDF (400KB) ( 801 )   Save
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    【Objective】 Soil organic nitrogen (N) is the main form of soil nitrogen, which is affected by fertilization practices. 【Method】 The Bremner method was employed to analyze soil organic N fractionation. After 29-year fertilization treatments, the changes of N supply capacity in a brown soil were studied in this paper. 【Result】 Compared with the control, neither single chemical fertilizer had the effect on the content of soil organic N, nor had the effect on the nitrogen composition. Application of manure with chemical fertilizer significantly increased the contents of all forms of hydrolysable organic N, especially the content of amino acid N. The contents of different forms of soil organic N in all treatments followed the order of amino acid N >non-hydrolysable N>ammonia N>unidentified hydrolysable N>amino sugar N. The distributions of all forms of organic N were similar, and decreased with layers’ depth. The basic rule is organic-inorganic fertilizer treatment>single organic manure fertilizer treatment>single chemical fertilizer treatment and the control. 【Conclusion】 Manure plus chemical fertilizer increased the content of most organic N, and was considered the best way for maintaining the soil fertility and sustainable agriculture.

    Spatial Interpolation and Sampling Numbers of the Concentration of Copper in Cropland Soil on County Scale Using Cokriging
    PANG Su,LI Ting-xuan,WANG Yong-dong,YU Hai-ying
    Scientia Agricultura Sinica. 2009, 42(8):  2828-2836 .  doi:10.3864/j.issn.0578-1752.2009.08.023
    Abstract ( 1034 )   PDF (1940KB) ( 907 )   Save
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    【Objective】 Studies on the spatial distribution and sampling numbers of the concentration of copper (Cu) on county scale were made to provide a help for the investigation of environmental quality of cropland soil. 【Method】 In this study, Cokriging was used for the interpolation of the concentration of Cu in cropland soil in Shuangliu county in Sichuan province. A total of original 623 measured data of the concentration of Cu in soil and 560, 498, 432 measured data by random were selected as target variable, original 623 measured data of soil organic matter (OM) content as auxiliary variable. The interpolation methods using Cokriging under different sampling numbers were evaluated for the suitability of estimating the spatial distribution of the concentration of Cu in soil on county scale. 【Result】 Compared with the ordinary Kriging under the same sampling numbers, the root-mean-square error produced by Cokriging decreased by 0.9% to 7.77%, correlation coefficient between the predicted value and the measured value increased by 1.76% to 9.76%. The prediction accuracy of original data reduced by 10% using Cokriging was still higher than original 623 data using ordinary Kriging and their interpolation maps were quite similar. 【Conclusion】 Cokriging was shown to be more accurate and economic method which could provide more information and help for the study on the spatial distribution of the concentration of Cu in soil on county scale.

    Investigation on Nitrate Pollution in Soils, Ground Water and Vegetables of Three Typical Farmlands in Beijing Region
    DU Lian-feng,ZHAO Tong-ke,ZHANG Cheng-jun,AN Zhi-zhuang,WU Qiong,LIU Bao-cun,LI Peng,MA Mao-ting
    Scientia Agricultura Sinica. 2009, 42(8):  2837-2843 .  doi:10.3864/j.issn.0578-1752.2009.08.024
    Abstract ( 1190 )   PDF (327KB) ( 763 )   Save
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    【Objective】 The aim of this study was to determine the nitrate pollution status of soil, groundwater and vegetables in three typical farmlands (cropland, vegetable field and orchard) in Beijing region. 【Method】 Based on the investigation method, the samples of the soil, groundwater and vegetables from different farmlands were collected and measured. In addition, attributes of all samples were recorded for dataset analyzing. 【Result】 The results showed that nitrate was substantially accumulated in soil profiles, while the soil nitrate concentrations of vegetable field and orchard were higher than those of cropland,which nitrate content in 0-30 cm soil of vegetable field and orchard were 3.8 and 1.2 times of the mean value of cropland respectively. Nitrate content of groundwater in vegetable field was 13.8 mg?kg-1 (with the over-standard ratio 44.8%), which was 2.8 folds of that in cropland. Nitrate content of groundwater under orchard was 9.3 mg?kg-1 (with the over-standard ratio 23.5%), which was 1.9 folds of that in cropland. The high concentrations of the nitrate in vegetables were measured, particularly green leafy vegetables ranked first with 2 685.5 mg?kg-1, followed by rhizome vegetables, cabbages and fruit vegetables. The over-standard ratios of rhizome vegetables, green leafy vegetables, fruit vegetables and cabbages were 80.9%, 37.9%, 29.7% and 2.2%, respectively. 【Conclusion】 It was revealed that the nitrate concentrations of soil, vegetable and groundwater were significantly or directly correlated with application levels of nitrogen fertilizer. Accordingly, soil nitrate accumulated obviously, vegetable and groundwater nitrate polluted severely both resulted from the high fertilization rate in vegetable field and orchard.

    HORTICULTURE
    Effects of Partial Root Zone Alternative Irrigation on Growth and Leaf Physiological Characteristics of Apple Trees
    WEI Qin-ping,LIU Song-zhong,WANG Xiao-wei,ZHANG Qiang,LIU Jun,DING San-jie
    Scientia Agricultura Sinica. 2009, 42(8):  2844-2851 .  doi:10.3864/j.issn.0578-1752.2009.08.025
    Abstract ( 998 )   PDF (384KB) ( 866 )   Save
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    【Objective】 To decrease the amount of irrigation and increase water use efficiency in apple orchard by improving the irrigation methods on the condition of maintaining the natural growth rate of apple trees.【Method】Effects of partial root zone alternative irrigation on growth and leaf physiological characteristics of three-year old roots of potted Gala apple trees were investigated in this study. 【Result】 Growth of new shoots and trunk diameter were retarded by the treatments of 1/4 and 2/4 root zone irrigation significantly, and that were released by increasing root zone irrigation. Leaf water potential and stomatal resistance were affected by partial root zone alternative irrigation, leaf water potential of 1/4 and 2/4 root zone irrigation was lower than that of 3/4 and 4/4 treatments, and stomatal resistance decreased with the amount of irrigation increasing significantly. Net photosynthetic Rate (Pn), transpiration rate (Tr) and stomatal conductance (Gs) of apple leaves decreased with root zone irrigation decreasing, and the extent of decreasing of transpiration rate was significantly larger than that of net photosynthetic rate, therefore, water use efficiency ( WUE ) increased. However, Pn, Tr and Gs of apple leaves were not affected by the amount of irrigation. At different growth stage, partial root zone irrigation had the same effect on Pn, Tr, Gs and WUE of apple leaves, while the highest value was shown at spring shoot growth stage. 【Conclusion】 Irrigation rate was the major factor affecting the growth of new shoots, however, leaf physiological characteristics were regulated by root zone irrigation. To maintain formal growth and development of apple trees, the root zone irrigation should not less than 50% of total root zone, the precipitation is not considered.

    Construction of DNA Fingerprinting Database of Citrus Cultivars (Lines)
    LEI Tian-gang,HE Yong-rui,WU Xin,YAO Li-xiao,PENG Ai-hong,XU Lan-zhen,LIU Xiao-feng,CHEN Shan-chun
    Scientia Agricultura Sinica. 2009, 42(8):  2852-2861 .  doi:10.3864/j.issn.0578-1752.2009.08.026
    Abstract ( 1146 )   PDF (506KB) ( 1501 )   Save
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    【Objective】 The aims of this study were to construct a DNA fingerprinting database of major citrus cultivars, which could provide a possibility of establishment of a technical standard system for purity and authenticity identification of citrus nursery trees. 【Method】 Simple sequence repeat (SSR) and inter-simple sequence repeat (ISSR) markers were used to analyze the DNA fingerprinting of 102 citrus cultivars(lines) and then to choose suitable primers for the construction of DNA fingerprinting database of citrus cultivars (lines). 【Result】 12 SSR primer pairs, with high polymorphisms and good repeatability, regarded as specific primers, which could identify 42 cultivars (lines), were selected from 200 SSR primer pairs. Meanwhile, 40 ISSR primers were used to analyze the DNA fingerprinting of 60 cultivars (lines) that can not be distinguished by SSR markers and 2 ISSR specific primers were chosen. As a result, a total of 70 citrus cultivars (lines) could be identified by the 12 SSR primers and 2 ISSR primers. Finally, a DNA fingerprinting database containing 70 major citrus cultivars (lines) was constructed by using those 12 SSR and 2 ISSR primers. 【Conclusion】 The results indicated that SSR and ISSR markers are suitable for the construction of DNA fingerprinting database of citrus cultivars (lines). Moreover, the fingerprinting database will provide a basis for genetic purity and authenticity fast evaluation of citrus nursery trees.

    Biotechnology and Genetic Breeding of Grapevine
    WANG Jun
    Scientia Agricultura Sinica. 2009, 42(8):  2862-2874 .  doi:10.3864/j.issn.0578-1752.2009.08.027
    Abstract ( 1234 )   PDF (357KB) ( 1170 )   Save
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    The development and application of biotechnology are permeating genetic breeding of grapevine as a whole. DNA markers facilitate investigations into the origins of existing cultivars and provide powerful tools for the creation of new cultivars. In particular SSR marker, is widely used in identifying grape cultivars, pedigree analysis, and constructing genetic map. DNA molecular marker-based genetic maps are accelerating grape breeding programs by permitting early selection for promising seedlings. Genetic mapping in combination with physical mapping can lead to the isolation of grape genes that control important traits. The application of technology in genetic transformation permits the targeted modification of existing grape cultivars. Therefore, biotechnology is dramatically changing the traditional methods of grapevine breeding today.

    The Degradation Mechanism of Carotenoids in Flue-Cured Tobacco and the Changes of the Related Enzymes Activities at Leaf-Drying Stage During the Bulk Curing Process
    SONG Zhao-peng,GAO Yuan,WU Sheng-jiang,XU Zi-cheng,GONG Chang-rong,ZHANG Wei-jian
    Scientia Agricultura Sinica. 2009, 42(8):  2875-2881 .  doi:10.3864/j.issn.0578-1752.2009.08.028
    Abstract ( 1001 )   PDF (323KB) ( 895 )   Save
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    【Objective】 The degradation mechanism of carotenoids and the changes of related enzymes activities in flue-cured tobacco at leaf-drying stage during the bulk-curing process were studied in order to provide a theoretical basis for optimization and perfection of curing technology. 【Method】 The effect of different rising speeds of temperature on the degradation of carotenoids and the related enzymes activities at the color-fixing stage during the bulk curing process was studied by using the electric-heated flue-curing barn designed and made by He’nan Agricultural University on the basis of curing technology with yellowing at low temperature middle humidity and leaf drying at middle humidity. 【Result】 The results showed that the contents of carotenoids decreased gradually at color-fixing stage during the bulk curing process; the degradation contents of carotenoids components (β-carotene, lutein, neoxanthin, violaxthin) of the slow heating curing (T1) was relatively large and was higher than the rapid heating curing (T2) by 10 %, 2 %, 32 % and 32 %, respectively, but there were no differences among treatments (P>0.05). Effect of different conditions of curing on the activities of enzymes were significant and lipoxygenase, phenylalanine ammonialyase, peroxidase and polyphenol oxidase had a bidirectional effect on the quality of tobacco leaves. It was beneficial to form more premise matter of aroma based on the higher enzymes activities at early leaf-drying stage. 【Conclusion】 The slow heating could regulate the change of various enzymes activities reasonably, make cell redox reaction reach to dynamic balance and make the degradation of carotenoids adequately. Meanwhile it could avoid the occurrence of browning reaction and provide a reference for improving the quality of tobacco and optimizing technology of bulk curing and aroma-enhancing further.

    Relationship Between Dehydration Tolerance and Soluble Sugars During Seed Development of Pachira macrocarpa
    LI Yong-hong,MA Ying-min,XU Bai-qiu,ZHAO Liang-jun
    Scientia Agricultura Sinica. 2009, 42(8):  2882-2891 .  doi:10.3864/j.issn.0578-1752.2009.08.029
    Abstract ( 1044 )   PDF (373KB) ( 636 )   Save
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    【Objective】 This work was aimed to investigate the relationships between dehydration tolerance and the composition and concentrations of soluble sugars during seed development of Pachira macrocarpa. 【Method】 Whole seeds or isolated embryos of P. macrocarpa at different developmental stages were used to investigate the changes of soluble sugar composition and concentration and their relationships with dehydration tolerance. 【Result】 The results showed that seed developed rapidly at 30-70 days after anthesis (DAA). Dehydration tolerance started to develop at 50 DAA and continue to increase until 70 DAA. when it reached the highest dehydration tolerance. Dehydration tolerance started to decline at 80 DAA but increased slightly at 90 DAA when seed are fully matured. The order of seed dehydration tolerance is 70 DAA>90 DAA>80 DAA>60 DAA>50 DAA. The dehydration tolerance of isolated embryo exhibited a similar pattern with the order of dehydration tolerance being 70 DAA>80 DAA>90 DAA>60 DAA>50 DAA>40 DAA. The main soluble sugars in early developing P. macrocarpa seeds were fructose, galactose and glucose. When seeds turned more mature, sucrose and maltose became dominant in soluble sugars from 40 DAA, raffinose and stachyose started to accumulate from 50 DAA and kept at high concentrations in the seed. The highest concentrations for sucrose and stachyose in seeds were observed 70 DAA. The ratio of reducing sugars to non-reducing sugars reached the lowest after 90 DAA, while the ratio of oligosaccharide to sucrose reached the highest. It is presumed that seeds switched to germination state from developmental state 80 DAA. 【Conclusion】 These results above suggested that there is a highly correlation between dehydration tolerance and development of P. macrocarpa seeds. Raffinose and stachyose are important facts for the formation of dehydration tolerance of P. macrocarpa seeds. The dehydration tolerance of the seeds are in close relationship with the content of the non-reducing sugars like the raffinose and stachyose, and the ratio of reducing sugars to non-reducing sugars.

    STORAGE·FRESH-KEEPING·PROCESSING
    Differentiation- and Proliferation-Inhibitory Effects of Sporamin from Sweetpotato on 3T3-L1 Preadipocytes
    XIONG Zhi-dong,LI Peng-gao,DENG Le,TANG Yu-ping,MU Tai-hua
    Scientia Agricultura Sinica. 2009, 42(8):  2892-2898 .  doi:10.3864/j.issn.0578-1752.2009.08.030
    Abstract ( 990 )   PDF (503KB) ( 1197 )   Save
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    【Objective】 The aim of this study is to investigate the effect of different concentrations of sporamin on differentiation and proliferation of 3T3-L1 preadipocytes, providing a theoretical basis for the development of prevention and treatment of obesity and anti-diabetes reagent in food industry. 【Method】 Isolation and purification of sporamin from sweet potato 55-2 was performed by ammonium sulphate precipitation in combination with ion-exchange-, gel filtration chromatography. With berberine as a positive control, different concentrations of sporamin (0, 0.025, 0.125, 0.250, 0.500 and 1.000 mg?ml-1, respectively) were used to treat 3T3-L1 preadipocytes. Intracellular fat accumulation and the degree of adipogenesis were observed using oil red O staining and quantified by colorimetry. Preadipocytes differentiation was measured by MTT spectrophotometry. 【Result】 Two sporamin proteins which were separated into sporamin A (31 kD) and sporamin B (22 kD) could be purified by ion-Exchange-, gel filtration chromatography. After being treated by different sporamin concentrations, the differentiation of 3T3-L1 preadipocytes was significantly inhibited compared with control. When the concentration of sporamin solution was 0.500 mg?ml-1, the accumulation of lipid droplets within the cells were obviously decreased and the optical density (OD) value of the solution from destained Oil Red O reached to 0.35, which was the lowest value (P<0.05). The proliferation of 3T3-L1 preadipocytes was significantly inhibited by treating at higher sporamin concentration. In addition, the restrictive effect was more obvious with the prolonging of treatment time (P<0.05). 【Conclusion】Differentiation and proliferation of 3T3-L1 preadipocytes could be inhibited significantly by addition of higher concentration sporamin. It is, therefore, suggested that sporamin is effective for weight loss.

    Advances in Biosynthesis Pathways and Regulation of Flavonoids and Catechins

    XIA Tao,GAO Li-ping
    Scientia Agricultura Sinica. 2009, 42(8):  2899-2908 .  doi:10.3864/j.issn.0578-1752.2009.08.031
    Abstract ( 1137 )   PDF (324KB) ( 2808 )   Save
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    Flavonoids are the major secondary metabolites with diverse biological activities in high plant. As one of the main subgroups of flavonoids, catechins usually account for 12%-25% dry weight in fresh leaves of tea plant [Camellia sinensis (L.) O. Kuntze]. Catechins are not only the most important components in tea flavor, but also possess a lot of physiological functions, such as antioxidant activity, antimutagenic and anticarcinogenic potential ,anti-cardiovascular diseases, anti-ultraviolet radiation and so on. This paper reviewed the progresses in the flavonoids or tea catechins branch pathway and regulation, subcellular localization and organization of flavonoid enzymes, and may provide additional insights into regulating gene expression and engineering the catechins biosynthesis in tea plant.

    ANIMAL SCIENCE·RESOURCE INSECT
    Influence of Cobalt and Copper Supplementation on Vitamin B12 Status and Nutrient Utilization in Sheep
    WANG Run-lian,ZHANG Wei,ZHU Xiao-ping,JIA Zhi-hai
    Scientia Agricultura Sinica. 2009, 42(8):  2909-2914 .  doi:10.3864/j.issn.0578-1752.2009.08.032
    Abstract ( 1070 )   PDF (274KB) ( 631 )   Save
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    【Objective】 The experiment was carried out to study the effects of different cobalt (Co) and copper (Cu) supplementation on vitamin B12 status and nutrient utilization in sheep. 【Method】 Twenty wethers with an average live weight of 22.9 ± 0.8 kg were randomly divided into five groups and fed with the control diet which was supplied 0.3 mg Co/kg DM to the basal diet, and 4 supplemental diets which were supplied either 0.3 or 0.6 mg?kg-1 DM of Co and 10 or 20 mg?kg-1 DM of Cu to the basal diet respectively for 8 weeks. The metabolism trial was conducted in the middle period of the feeding experiment. The blood samples were collected at 2-week intervals. Vitamin B12 and folate concentrations were analyzed using electrochemistry luminescence method. Plasma methylmalonic acid was analyzed by a modified GC method. Plasma level of homocysteine was analyzed by fluorescence immunoassay.【Result】 Supplementation of Co and Cu at different levels improved plasma vitamin B12 concentration which was increased with feeding time, but stable after 6 weeks. Vitamin B12 status was accounted for by Co intake with no collaborate effects by supplementation of different levels of Co and Cu. The plasma concentrations of methylmalonic acid, homocysteine, folic acid and glucose did not show the consistent results with plasma vitamin B12 which was considered to be resulted from Cu effects. Addition of Co and Cu at different levels had no influence on digestibility of DM, OM, CP and NFE and N metabolism (P>0.05), but the digestibility of fat and fibre (P<0.01) was enhanced by supplementation of appropriate levels of 0.3 mg?kg-1 DM of Co and 20 mg?kg-1 DM of Cu. 【Conclusion】 In conclusion, supplementation of Co and Cu at different levels has no influence on vitamin B12 status. The optimum ratio of Co and Cu in diet could enhance the nutrient utilization.

    Study on Bacterial and Protozoal Community Structure of Xuhuai White Goat Rumen
    WANG Meng-zhi,WANG Hong-rong,XU Ai-qiu,ZHANG Jie,CHEN Xu-wei
    Scientia Agricultura Sinica. 2009, 42(8):  2915-2922 .  doi:10.3864/j.issn.0578-1752.2009.08.033
    Abstract ( 1140 )   PDF (350KB) ( 822 )   Save
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    【Objective】 The objectives of this paper were to investigate microbial population in the rumen of Xuhuai white goat, including bacteria and protozoa. 【Method】 Four Xuhuai white goats fitted with rumen cannula were used to provide rumen liquor. 16S rDNA amplified by PCR, and the techniques of cloning and sequence analysis, were applied in this work to interpret the bacterial community structure, as well as the method of cell-counting for protozoal group. 【Result】 The results showed that, rumen bacteria could be divided into two main clusters, which were R. bromii, and R-7, while XHGR2 belonged to another cluster of R. flavefaciens. Ruminococcus had a big size in bacterial population, which accounting for 33.33% against total clones. Rumen protozoa were up to 44.83% of rumen total biomass, a little lower than bacteria in the proportion. There were several protozoal genera, such as Entodinium, Diplodinium, Epidinium, Ophryoscolex, and Isotrichidae, were detected in the rumen. Entodinium was more density than the others, and accounting for 74.25% of the total population. 【Conclusion】 All in all, the biomass of protozoa was close to that of bacteria, in the rumen of Xuhuai white goat. Ruminococcus sp. and Entodinium sp. were the majority groups in the rumen, for the groups of bacteria and protozoa, respectively.

    Effect of Nanometer-Selenium on the Development of Reproductive Function in Prepuberital Male Boer Goat
    YANG Ru-jie,SHI Li-guang,YUE Wen-bin,XUN Wen-juan,ZHANG Chun-xiang,REN You-she,ZHAO Ping-wei,LEI Xiao-feng
    Scientia Agricultura Sinica. 2009, 42(8):  2923-2929 .  doi:10.3864/j.issn.0578-1752.2009.08.034
    Abstract ( 1276 )   PDF (566KB) ( 707 )   Save
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    【Objective】 The experiment was conducted to study the effect of nano-selenium on reproductive function in male Boer goat from weaned to sexual maturity. 【Method】 Total 20 healthy goats were randomly divided into two treatments in 10 replications, and they were fed with a basal diet supplemented with 0 (control) or 0.3 mg?kg-1 Se from nano-selenium. The experiment lasted for 90 d before 10 weeks pretesting, and the blood samples were collected and separated serum for sexual hormones every 30 days. The testis obtained, measured the Se concentration and the activity of GSH-Px, fixed and made the microscopic section, observed the testicular microstructure. At the end of experiment, semen quality in each group was analyzed, ultrastructure of spermatozoa was observed through TEM. 【Result】 The results showed that the development of seminiferous tubules, interstitial tissue and germ cells were affected by supplementing nano-Se in basal diets. Dietary supplementation with nano-Se increased testis Se content, the activity of GSH-Px (P<0.01) significantly. Testosterone, luteinizing hormone and follitropin were not affected by supplementation Se during the phase of 30-60 d, and increased significantly in the phase of 90 d compared with control. Sperm activity increased by 10% and abnormality sperm decreased by 27%, respectively (P<0.05), and no change in sperm quantity and density was observed. The longitudinal sections of midpiece of sperm mitochondria showed the change of the biological characters and arranged loosely. 【Conclusion】 These results indicated that supplementation of nano-Se affected the reproductive function of prepubertital goat, and improved the sperm quantity.

    Polymorphisms of the Gene OLA-DQA2 Exon 2 in Tibetan Sheep
    LIU Xiu,HU Jiang,LUO Yu-zhu
    Scientia Agricultura Sinica. 2009, 42(8):  2930-2936 .  doi:10.3864/j.issn.0578-1752.2009.08.035
    Abstract ( 1038 )   PDF (602KB) ( 698 )   Save
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    【Objective】 There is a foot-rot disease in the population of Tibetan sheep, which leads to the loss of sheep on death. Gene OLA-DQA2 is associated with foot-rot disease. The polymorphism and variation of gene OLA-DQA2 exon 2 was investigated in order to find the best alleles for foot-rot resistance in the further observation by means of phenotype and genotype. 【Method】 Fragments of DNA containing OLA-DQA2 exon 2 were amplified using PCR. Single-strand conformational polymorphism (SSCP) analysis and DNA sequence analysis were employed to detect genetic variation in 216 Tibetan Sheep (including ones with foot-rot). 【Result】 Fifteen nucleic acid sequences were identified. Eight novel alleles were found for the first time, respectively named OLA-DQA2*H, *I, *J, *K, *L, *M and *N. Thus the number of alleles identified is increased from 23 to 31. Seventeen-one nucleotide polymorphisms were found in the analysis of gene sequences, which mainly came from point mutation, including transition of 39 (54.9%) and 23 of transversion (32.4 %). 【Conclusion】 Tibetan sheep DQA2 gene exon 2 has high level of sequence polymorphism. The population may have strong resistance to genetic resources. The best alleles will be found by further observation from phenotype and genotype of the DQA2 gene in the near future. Consequently, the plan of disease resistance will be carried out in sheep breeding practice.

    Microsatellite Markers’ Linkage Analysis of the Comb Traits of Chicken
    LIANG Du,WANG Jin-fu,LI Yan,ZHAO Jie,ZHANG Cheng-xian,ZHAO Yan,LIAO He-rong
    Scientia Agricultura Sinica. 2009, 42(8):  2937-2942 .  doi:10.3864/j.issn.0578-1752.2009.08.036
    Abstract ( 980 )   PDF (333KB) ( 852 )   Save
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    【Objective】 To establish a linkage map of the chromosome 2 in the chicken-F2 resource group with cockscomb trait record, and to determine a preliminary mapping for the gene of controlling comb trait combined with the phenotypic analysis.【Method】 Through test cross, 2 Tulufan fighting cocks with the homozygous pea-comb genotype and 6 rose comb hens with the homozygous rose-comb genotype were chosen as the parents. Four hundred and thirty six chickens of the F2 generation group were built by the F2 generation experimental design, and the genetic linkage map of EL (East Lansing) family was also referred. Meanwhile, the 14 microsatellite markers on the chromosome 2 of chicken were selected, and the family genetic linkage map of chromosome 2 was built preliminarily by using MapMaker/EXP3.0 software. In addition, the linkage analysis of cocks comb gene was completed through the LOD scoring method. 【Result】 By the χ2 test, the proportion of differentiation of the F2 resource group was accorded with the law of independent segregation of classic Mendelian inheritance. Except for the MCW0157, the other 13 microsatellite markers all could have linkage, and the genetic linkage map of chromosome 2 in this family was similar with the EL family’s. 【Conclusion】 The site MCW0082 of chicken chromosome 2 may have linkage with the rose comb gene.

    Separation and Enrichment of sRNAs from Honeybee (Apis mellifera L.) and Its Quality Detection by Library Construction
    CHEN Xuan,YU Xiao-min,ZHENG Huo-qing,CAI Yi-mei,HU Fu-liang
    Scientia Agricultura Sinica. 2009, 42(8):  2943-2948 .  doi:10.3864/j.issn.0578-1752.2009.08.037
    Abstract ( 1213 )   PDF (394KB) ( 691 )   Save
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    【Objective】 The aim of this study is to separate and enrich sRNAs from honey bee (Apis mellifera L.), and construct a library to test whether these sRNAs could meet requirements of high-throughput sequencing research. 【Method】 sRNAs (15-40 nt) from the queen, worker and drone bees at different development stages were separated and enriched, then performed reverse transcription on adapter ligated sRNAs followed by PCR amplification. After constructing the cDNA library, blue-white selection was performed and 288 single clones were selected for sequencing and analysis. 【Result】 214 high quality sequences of 15-39 bp, including 65 sme-miR-71c (mir-2), 5 ncRNAs containing tm-RNA, intron_ghI and 5.8S rRNA, 28 tRNAs, 33 siRNAs and other sRNAs, 1 CDS, and 82 not mapped sequences, were obtained. 【Conclusion】 This result indicates that the sRNA enrichment is effective and the samples we prepared could be used for high-throughput sequencing.

    VETERINARY SCIENCE
    Molecular Epidemiology Analysis on Porcine Circovirus Type 2 in Some Regions of China in 2007
    ZHANG Jian-wu,ZHUANG Jin-shan,LIU Chang-long,WANG Xiao-min,YUAN Shi-shan
    Scientia Agricultura Sinica. 2009, 42(8):  2949-2957 .  doi:10.3864/j.issn.0578-1752.2009.08.038
    Abstract ( 977 )   PDF (441KB) ( 620 )   Save
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    【Objective】 A pair of primer was designed for detection of porcine circovirus type 2 from Shanghai, Jiangxi, Shandong, Jiangsu, Henan and Hunan in 2007. 【Result】 Results indicated that the positive percentage of PCV2 was 24.51% (63/257) and positive samples were detected from healthy pigs. Gene amplificated from PCR product was cloned and sequenced. Sequence analysis illustrated that nucleotide and amino acid homology of ORF2 of PCV2 isolates were 84.4%-100% and 82.5%-100%, respectively, and defferent belong to defferent groups . 【Conclusion】 There were two groups of PCV2 strains prevailing in China, the PCV2b group strains were predominant prevailing strain (70.97%, 22/31) , but the PCV2a group strains were prevailing also. There was no difference in genotype of PCV2 isolated from defferent geographical regions. Some PCV2 strains owned character of high pathogenic PCV2 implied that there was a high pathogenic PCV2 prevailing in China.

    Influenza Virus Receptor Detection on Chicken, Pigeon and Tiger Respiratory and Intestine Tract Epithelium Cells
    MA Ming,LIU Yue-huan,CHEN Ming-yong,HAN Chun-hua,LIN Jian
    Scientia Agricultura Sinica. 2009, 42(8):  2958-2965 .  doi:10.3864/j.issn.0578-1752.2009.08.039
    Abstract ( 1021 )   PDF (731KB) ( 803 )   Save
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    【Objective】 To detect the type and distribution of influenza virus receptors in chicken, pigeon and tiger, then find the mechanism to explain the difference of these animals’ affectability to avian influenza virus. 【Method】 The type of SAα2, 6Gal and SAα2, 3Gal linkage on these animals larynx, trachea, lung and intestine (colon) epithelium cells was detected by digoxigenin-labeled lectin staining. 【Result】 Abundant SAα2, 3Gal and slight SAα2, 6Gal on specific-pathogen free chickens upper respiratory tract epithelium cells were observed, the alveolar epithelium cells only express SAα2, 3Gal, however the colon epithelium cells express neither SAα2, 6Gal nor SAα2, 3Gal. Adult pigeon upper respiratory tract epithelium cells only express SAα2, 6Gal, but not SAα2, 3Gal. Pigeon lower respiratory tract express neither SAα2, 6Gal nor SAα2, 3Gal.Pigeon colon epithelium cells only express SAα2, 3Gal. There are abundant SAα2, 6Gal and SAα2, 3Gal on tiger respiratory and intestine tract epithelium cells. 【Conclusion】 These data have provided a rational explanation for why chickens and tigers are susceptible to avian influenza virus, while pigeons are not.

    Detection of Plasmid-Mediated Quinolone Resistance in Clinical Isolates of Enterobacteriaceae from Avian
    YUE Lei,JIANG Hong-xia,LIU Jian-hua,LIAO Xiao-ping,LI Shu-juan,CHEN Xue-ying,WU Cai-xia,ZHANG Xiao-yun,LIU Ya-hong
    Scientia Agricultura Sinica. 2009, 42(8):  2966-2971 .  doi:10.3864/j.issn.0578-1752.2009.08.040
    Abstract ( 1222 )   PDF (362KB) ( 729 )   Save
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    【Objective】 To detect plasmid-mediated quinolone resistance (PMQR) qnr, qepA, aac (6′)-Ib-cr genes in clinical isolates of Enterobacteriaceae from avian in Guangdong province. 【Method】 Susceptibility of 84 strains to 27 antimicrobial agents were determined by agar disc diffusion method. All of the 84 strains were screened for the qnr, qepA, aac (6′)-Ib-cr genes by PCR. Mutations in the quinolone-resistance-determining region (QRDRs) of the gyrA, gyrB, parC and parE gene was detected in PMQR positive strains. 【Result】 The isolates showed high rate of resistance to antimicrobial agents widely used in veterinary clinical medicine such as exrofloxacin, fleroxacin, ampicillin, trimethoprim-sulfamethoxazole, doxycycline, and rifampin, streptomycin and roxithromycin. All of the 84 strains showed multiple-resistance to at least 6 drugs. However most of them were sensitive to ampicillin-sulbactam, aztreonam, polymyxin E and cephalexin. A qnrB6 and aac (6′)-Ib-cr gene was identified in a Klebsiella pneumoniae. Mutation of S→I occurred in the QRDR of the gyrA 83 site, while no mutations were detected in QRDRs of gyrB, parC and parE. 【Conclusion】 Enterobacteriaceae isolated from avian in Guangdong showed high level multiple-resistance to widely used drugs. This is the first report on two PMQR determinants, qnr and aac (6′)-Ib-cr, in clinical isolates of K pneumoniae from avian. The emergency of PMQR genes may indicate a more widespread dissemination of resistance to quinolones in avian industry.

    Construction of MSTN Knock-out Porcine Fetal Fibroblast
    LI Jing-fen,YU Hao,YUAN Ye,LIU Di
    Scientia Agricultura Sinica. 2009, 42(8):  2972-2977 .  doi:10.3864/j.issn.0578-1752.2009.08.041
    Abstract ( 1102 )   PDF (483KB) ( 786 )   Save
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    【Objective】 The objective of this study is to get MSTN knock-out porcine fetal fibroblast. 【Method】 Construction of targeting vector: Neomycin phosphotransferase gene was used as positive-selecting gene, herpes simplex thymidine kinase gene was used as negative-selecting gene. Homologous arms were respectively inserted into the two sides of Neo gene. The 5.3 kb homologous left arm contains partial 5' MSTN gene, the whole exon1 and exon2, and part of intron2, while the 0.8 kb homologous right arm contains part of exon3 and partial 3' MSTN gene. Taking the tissue of 35 days Yorkshire as materials, fibroblast lines were successfully established by trypsin digestion. Targeting vector was introduced into the fetal fibroblast of Yorkshire by lipofectamin-mediated DNA transfection methods, after transfection, selected with G418 (250 μg?ml-1) for 7 days, then continuous selected with 200 μg?ml-1 G418+2 μmol?L-1GANC. Semi-quantitative RT-PCR analysis of MSTN mRNA expression was done using the total RNAs from pig fetal fibroblast before and after transfection. 【Result】 The replacement vector was successfully constructed, which can knock out partial intron2 and exon3 of myostatin. Five resistance cell strains were gotten, through PCR identification, one strain took place correct homologous recombination. The amount of MSTN mRNA expression of transgenic cells is obviously declined. 【Conclusion】 MSTN knock-out porcine fetal fibroblast was obtained.

    RESEARCH NOTES
    Breeding of the Maize Monogenic br-2 Dwarf Lines
    HE Chuan,ZHENG Zu-ping,XIE Shu-guo,LI Zhong,LIU Dai-hui
    Scientia Agricultura Sinica. 2009, 42(8):  2978-2981 .  doi:10.3864/j.issn.0578-1752.2009.08.042
    Abstract ( 955 )   PDF (281KB) ( 697 )   Save
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    【Objective】 The experiment was conducted to study the effects of breeding dwarf maize inbred lines by using the introduced tropical germplasm with monogenic br-2. 【Method】 Utilizing the gene br-2 in maize controlling the dwarf characteristic, based on the principle of gene recombination, backcross of selection was made through introduction of tropical germplasm. 【Result】 The main results showed that the dwarf lines Nan381 and Nan387 gave excellent combining ability. As to the breeding method, the hybrids Nanyu8 and Longdan9 have been examined and are widely extended in Southern China. 【Conclusion】 Monogenic br-2 was recombined with some genes controlling desirable agronomic characters, such as disease resistance, lodging resistance and narrow leaf, and the disadvantages of original br-2 inbred lines were overcome, including short internode, wide and dense leaves, high barrenness, which could be used for maize breeding in the future.

    Growth and Allocation of Photosynthetic Produces in Cotton Under Alternative Partial Root-Zone Irrigation
    PAN Li-ping,LI Yan,TANG Li-song
    Scientia Agricultura Sinica. 2009, 42(8):  2982-2986 .  doi:10.3864/j.issn.0578-1752.2009.08.043
    Abstract ( 986 )   PDF (295KB) ( 694 )   Save
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    【Objective】 The objective of this experiment is to study the effect of alternative partial root-zone irrigation on the physiological and ecological characters of cotton. 【Method】With pot-grown cotton plants, the current study compared the physiological effects, growth and allocation of photosynthetic produces under alternative partial root-zone irrigation (APRI), fixed partial root-zone irrigation (FPRI), and conventional full root-zone irrigation (CK). 【Result】 It was found that with 50% reduction in the amount of irrigation as compared with CK, biomass in APRI reduced by only 10%, while in FPRI the reduction was 23%. The results also revealed that although the total amounts of root biomass were the same in every treatment, the root/shoot ratio in APRI and FPRI increased significantly. Further analysis revealed that, the total amount of absorbing roots in CK and APRI were approximately the same, but higher than in FPRI in both cases. With partial root-zone irrigation, ABA content in leaves and stems increased significantly, which regulated the water loss through adjusting stomatal opening.【Conclusion】Results show that APRI could stimulate the growth of absorbing roots, adjust allocation of photosynthetic produces between shoots and roots, therefore it is a promising irrigation method for saving water and keeping reasonable crop product.
    Cell Wall Metabolism and Its Regulation in Harvested Pyrus ussuriensis Maxin. cv. Jingbaili Fruit During Ripening
    WEI Jian-mei,MA Feng-wang,GUAN Jun-feng,YUAN Jun-wei,ZHU Xiang-qiu
    Scientia Agricultura Sinica. 2009, 42(8):  2987-2996 .  doi:10.3864/j.issn.0578-1752.2009.08.044
    Abstract ( 1018 )   PDF (436KB) ( 1098 )   Save
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    【Objective】 This experiment was aimed to discuss the relationship between cell wall metabolism and fruit softening, and their regulation in harvested ‘Jingbaili’ pear to provide a theoretical basis for improving fruit quality and inhibiting fruit softening.【Method】 Fruits of pear cultivar ‘Jingbaili’ (Pyrus ussuriensis Maxin. cv. Jingbaili) were used to investigate the changes in cell wall compositions, their metabolism-related enzymes, and their regulation by low temperature (0℃) and ethylene (1-MCP or ethephon). 【Result】 The contents of cell wall materials (CWM), covalent pectin (CSP), cellulose and semicellulose decreased, while the content of ionic pectin (ISP) and soluble pectin (WSP) increased during fruit softening. Activities of pectinesterase (PME) and polygalacturonase (PG) enhanced on the 3 rd day after harvest, and their peaks appeared on the 9th and 12 th days, respectively. Activities of β-galactosidase (β-Gal) and α-L-arabinofuranosidase (α-L-Af) increased initially and maintained this trend by the end of storage, while cellulase activity declined during fruit softening. Analysis of correlation showed that semicellulose, ISP and CSP had more relationship with firmness than WSP and cellulose; β-Gal and α-L-Af had more significantly correlation not only with firmness, but also with cell wall compositions than the other enzymes. Treatments with 0℃ and 1-MCP decreased the declines in cellulose, semicellulose and CSP contents, as well as the increases in ISP and WSP contents. Meanwhile, activities of β-Gal, α-L-Af, PME and PG were inhibited significantly, postponing fruit softening, but fruit softening was not facilitated by ethephon. 【Conclusion】 The changes in cell wall compositions had an important relationship to fruit ripening, which were resulted by their metabolism-related enzymes. Among them, β-Gal and α-L-Af could play more roles at early softening stage, PME and PG accelerated late fruit softening, while cellulase showed little effect. Fruit softening was obviously inhibited by 0℃ or 1-MCP, but it was not markedly facilitated by ethephon.

    Application of Recombinant CE18 Protein for Diagnosis of Ovine Metacestodiasis
    LIU Hong-xia,CAI Xue-peng,ZHANG Shao-hua,GUO Ai-jiang,YAN Hong-bin,GOU Hui-tian,FU Bao-quan,JIA Wan-zhong
    Scientia Agricultura Sinica. 2009, 42(8):  2997-3002 .  doi:10.3864/j.issn.0578-1752.2009.08.045
    Abstract ( 1035 )   PDF (254KB) ( 532 )   Save
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    【Objective】 To investigate the recombinant CE18 (Cystic Echinococcosis protein 18 kD) antigen for immunodiagnosis of metacestode diseases in sheep. 【Method】 A total of 259 sera samples from sheep infected with larval stage Taenia multiceps (Tm, 18), T. hydatigena (Th, 15) or Echinococcus granulosus (Eg,19), and sheep from an epidemic area of echinococcosis (194) and normal sheep (control, 13) were examined by enzyme-linked immunosorbent assay (ELISA) to detect the antibodies against the rCE18 protein. The significant difference method was used to evaluate the values of rCE18 protein as an antigen for diagnosis of cestode-larva diseases in sheep. Analysis of rCE18 protein from different species was performed using biological softwares. 【Result】 Similarities of homologous CE18 protein among different taeniid genera were up to 99% at amino acid level. The sero-positive rate of rCE18-ELISA was 38.89% in Tm, 73.33% in Th, 100% in Eg, and 76.14% in the epidemic area of echinococcosis, respectively, whereas that of the healthy control was negative. 【Conclusion】 CE18 protein may be a useful antigen for the immunodiagnosis of sheep infected with the larva of cestodes, especially for Eg and/or Th.

    Cloning, Sequence Analysis and Transcription Activity of a Chicken U6 Promoter

    WANG Yong-juan,SHEN Peng-peng,ZHANG Xin-yu,XIA Xiao-li,SUN Huai-chang
    Scientia Agricultura Sinica. 2009, 42(8):  3003-3008 .  doi:10.3864/j.issn.0578-1752.2009.08.046
    Abstract ( 1160 )   PDF (413KB) ( 1162 )   Save
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    【Objective】 To cloning avian U6 promoter for construction of short interference RNA (siRNA) expression vectors in avian cells. 【Method】 A putative chicken U6 promoter from chicken genomic DNA was amplified by PCR. After sequencing and bioinformatics analysis, the putative promoter was inserted into the reporter plasmid pEGFP-N1 together with GFP-specific short hairpin RNA (shRNA) and resulted in a siRNA expression vector pGFP-U6-shRNA. Then, using human H1 promoter-driven siRNA expression vector pGFP-H1-shRNA as the control, the simian-originated COS-1 cells or chicken embryonic fibroblast (DF-1) cells were cotransfected with the siRNA expression vector pGFP-U6-shRNA, and the GFP-positive cell numbers and total fluorescence were detected by fluorescence microscopy and flow cytometry. 【Result】 The PCR product was 560bp long and located on chicken chromosome 28 with a percentage identity of 97.2% to the published chicken U6-3 promoter. Bioinformatics analysis showed that the putative chicken U6 promoter contained several Oct-1 motifs and a weak TATA box without other Pol Ⅲ promoter elements. In COS-1 cells, transfection with pGFP-U6-siRNA resulted in significant decreases in both the number of GFP-positive cells and total fluorescence, but significance was lower than that of transfection with pEGFP-H1-shRNA. While in DF-1 cells, transfection with pGFP-U6-shRNA resulted in significantly higher gene silencing effect than cotransfection with pEGFP-H1-shRNA. 【Conclusion】 These data suggest that a chicken U6 promoter was successfully cloned, which can efficiently transcribe gene-specific siRNA expression in avian cells.