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Table of Content

    10 August 2006, Volume 39 Issue 8
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES
    Construction of Rice Chloroplast Multicistron Site Integration Expression Vector and Its Transgene to Tobacco Chloroplast
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    Scientia Agricultura Sinica. 2006, 39(8):  1511-1517 . 
    Abstract ( 1827 )   PDF (452KB) ( 1598 )   Save
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    【Objective】The rice (Oryza sativa) chloroplast multicistron site integration expression vector will be transformed for expression into the tobacco chloroplast.【Method】According to the published correlative DNA sequence, a series of elements for construction of the rice chloroplast multicistron site integration expression vectors have been cloned using a PCR technique, including Prrn (a modified plastid ribosomal RNA operon promoter) , psbA3′ (the 3′ region of the plastid psbA gene), aadA gene (encoding aminoglycoside 3′-adenylytransferase), man gene (encoding mannase), gfp gene (encoding green fluorescence protein) and a rice chloroplast high-frequency homologous recombination crDNA fragment (psbC/trnG,3362bp). A rice chloroplast multicistron expression vector pLM21 (-psbC-Prrn-RBS-man-RBS-gfp-RBS-aadA-psbA3′-trnG-) was constructed with these elements. Then the tobacco leaves were bombarded 5 times with gold particles coated with the vector pLM21. 【Result】 Four tobacco chloroplast transgenic shoots were obtained after the tobacco leaves had been grown in the screening medium. All the genes man, gfp and aadA , having been transformed to the tobacco chloroplast, were confirmed by PCR. The expression of these genes was identified by the screening medium, the laser scanner and the Western blot. The multicistron expression cassette integrating in tobacco chloroplast genome DNA was confirmed by RFLP. 【Conclusion】 All these showed that the genes man, gfp and aadA in the rice vector pLM21 were integrated in the tobacco chloroplast genome DNA and expressed in the tobacco chloroplast.
    Determination and Evaluation of Puroindoline Alleles in CIMMYT Wheats
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    Scientia Agricultura Sinica. 2006, 39(8):  1518-1525 . 
    Abstract ( 1944 )   PDF (359KB) ( 1177 )   Save
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    【Objective】Grain hardness, controlled by a hardness (Ha) gene, serves as a basis for classification and marketing of common wheat (Triticum aestivum L.) quality and has a profound effect on milling and end-use quality. CIMMYT is one of the most important places that regularly offer germplasm to Chinese wheat breeding program. This study can provide useful information to introduce wheat to China. 【Method】 A total of 236 wheat lines from CIMMYT crossing program, including common wheat cultivars and advanced lines derived from synthetic hexaploid wheat × common wheat crosses, are used to detect variation of puroindoline alleles by specific-primers PCR amplification and modified SDS-PAGE. PSI (particle size index) hardness was also measured for 160 genotypes. 【Result】 Results indicated that 165 hard wheat lines are Pina-D1b types and the remaining 37 are Pinb-D1b types, which are non-CIMMYT cultivars or their pedigrees contain non-CIMMYT cultivars. Pina-D1j/Pinb-D1i, Pina-D1c/Pinb-D1h, Pina-D1a-Pinb-D1i, Pina-D1a-Pinb-D1j, and wild type (Pina-D1a/Pinb-D1a) are present in 34 soft types. Genotypes with Pina-D1b are significantly harder (lower PSI hardness) than genotypes with Pinb-D1b. Genotypes with Pina-D1c/Pinb-D1h and Pina-D1a/Pinb-D1i are significant harder (lower PSI hardness) than genotypes with Pina-D1j/Pinb-D1i and Pina-D1a/Pinb-D1a. In addition, both Pinb-D1h and Pinb-D1i encode the same polypeptides and a tryptophan substitute (arginine) at position 28, which is the major reason for soft endosperm. In comparison with wild type (Pina-D1a/Pinb-D1a), no change was found in close to tryptophan-rich domain of puroindoline in other soft genotypes except for Pinb-D1h and Pinb-D1i, which may be the main reason that mutation types still remain soft endosperm. 【Conclusion】 It is concluded that all of Pinb-D1b types are non-CIMMYT cultivars or their pedigrees contain non-CIMMYT cultivars and PSI of puroindoline alleles from Ae.tauschii are difference.
    Hitchhiking Effect Mapping: A New Approach for Discovering Agronomic Important Genes
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    Scientia Agricultura Sinica. 2006, 39(8):  1526-1535 . 
    Abstract ( 1988 )   PDF (624KB) ( 1762 )   Save
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    Beside natural selection, today's cultivated crops have experienced two types of strong artificial selections: domestication and modern breeding. Domestication has led to a giant genetic structure differentiation between cultivars and their wild relatives, and modern breeding has created further genetic structure differentiation between the modern varieties and the landraces. In a genome, genetic diversity at a locus experienced strong selection is significantly lower than that at other loci non-experienced selection and diversities in the flanking regions also declines. This phenomenon is called the hitchhiking effect or genetic selection sweep. The genomic regions with selection sweep could be detected through scanning a number of released varieties or natural populations with molecular markers. Thereafter, agronomic important traits linked with these regions could be detected using Marker/Trait association analysis. Fine scanning of these genomic regions would help to determine the sizes of these regions and to discover the favorable alleles or even the key genes. This could provide very valuable information for gene isolation and molecular design of new varieties. Establishment of high density genetic linkage maps in the major crops and availability of high throughput genotyping platform make it possible for discovering agronomic important genes through marker/trait association analysis. Based on the available publications, we give a brief introduction of the hitchhiking effect mapping approach using the plant height, 1000-grain weight, and phosphorus-deficiency tolerance as examples in wheat.
    TILLAGE & CULTIVATION·PHYSIOLOGY & ECOLOGY
    Symptomatic of the Shrunk-grain Panicle and the Change Characteristics in Its Grain
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    Scientia Agricultura Sinica. 2006, 39(8):  1536-1544 . 
    Abstract ( 1503 )   PDF (501KB) ( 1371 )   Save
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    【Objective】Over the past two years, an abnormal growth phenomenon called shrunk-grain panicle has occurred in a large area in Jiangsu Province. The phenomenon was described in detail by figures and characters in this paper. 【Method】With Japonica rice Wuyujing 3 as the experimental material, characteristics of grain morphology distribution and grain weight were studied. Normal grains and Shrunk-grain Panicle were sampled from several representative areas. 【Result and Conclusion】The length, width, and weight of the normal grains were distributed as regular, continuous and single peaked. Plant growth typically had a right-leaning tendency. On the contrary, the distribution of the grain morphology and weight were irregular and nearly doubled that of the Shrunk-grain Panicle. The proportion of the cumulative distribution in the two kinds of peaks was closely related with the degree of Shrunk-grain Panicle. The paper discusses analysis of the phenomenon's symptoms, problems, and diagnosis.x
    Correlation Between Antioxidation, and Content of Total Phenolics and Anthocyanin in Black Soybean Accessions
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    Scientia Agricultura Sinica. 2006, 39(8):  1545-1552 . 
    Abstract ( 3175 )   PDF (328KB) ( 1637 )   Save
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    【Objective】To study the correlations between antioxidations, contents of total phenolics and anthocyanin in 127 accessions of black soybean.【Method】 A t-test, a fast clustering procedure and a correlation coefficient analysis were used for experimentation.【Result】The ranges of total antioxidant capacity (TAC), total phenolics and anthocyanin contents in 127 black soybean accessions were 0.44-3.56 mmol·g-1, 7.05-74.82mg·g-1 and 0.22-1.87mg·g-1, respectively, displaying significant genotype differences. The big differences in TAC, total phenolics and anthocyanin contents existed among various types of accessions from geographical regions. The differences between accessions from black and yellow soybeans, Spring and Autumn, Summer and Autumn, Dongbeichun and Nanfangchun, Dongbeichun and Nanfangxia, Beifangchun and Nanfangchun, Beifangchun and Nanfangxia were significant at 0.01 or 0.05 levels respectively. The general tendency was that the TAC, total phenolics and anthocyanin contents of Beifangchun accessions were higher than those of Dongbeichun ones, those of Nanfangchun accessions were the least. 127 black soybean accessions could be clustered into 6 clusters which consist of 3, 24, 20, 31, 37 and 12 accessions, respectively. Most significant (P<0.01) correlations existed respectively between the TAC and total phenolics content, TAC and anthocyanin content of black soybean.【Conclusion】The results showed total phenolics and anthocyanin in black soybean seed coat were the important antioxidation substances.
    Application of Agent in Agricultural Expert System Inspection Software
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    Scientia Agricultura Sinica. 2006, 39(8):  1553-1558 . 
    Abstract ( 1546 )   PDF (224KB) ( 1036 )   Save
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    In reference to the status quo of research and the application of agricultural expert systems, this paper analyzes problems existing in the current development and puts forward the idea of research and development for agriculture-specific software. The experimental application, Agent, examines agronomist research methodology, system design, and technology implementation. In addition, this paper addresses application outlook, potential problems and the development trend of Multi-Agent-based inspection software for agricultural expert systems.
    PLANT PROTECTION
    Isolation and Characterization of NBS-LRR Resistance Gene Homology Sequences from Wheat
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    Scientia Agricultura Sinica. 2006, 39(8):  1558-1564 . 
    Abstract ( 1897 )   PDF (305KB) ( 1529 )   Save
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    【Objective】In this study, resistance gene homology fragments from wheat were isolated using homology-based method. 【Method】Two pairs of primers were designed according to the amino acid conserved regions NBS-LRR of the cloned plant disease resistance genes, and the reverse transcription-polymerase chain reaction (RT-PCR) was used.【Result】Three open-reading NBS resistance gene analogues (RGAs) have been obtained. They were named as PS13-1, PS13-2, and S2A2 respectively from the RNA of TcLr35 carrying the Lr35 gene conferring resistance against wheat leaf rust by a reverse transcription-polymerase chain reaction (RT-PCR). The nucleotide sequences of the three RGAs were 239bp, 289bp and 539bp encoding 78, 84 and 177 amino acids respectively. Homology research showed that the nucleotides of PS13-1 and PS13-2 were 91% identical to wheat powdery mildew resistance gene PM3b, and the nucleotide of S2A2 was 91% identical to the sequence from the mRNA of barley. BLASTp analysis indicated that three RGAs contained the conserved motifs of NB-ARC (such as P-loop, kinase2, kinase3a and transmembrance domain). Northern hybridization showed that the RGAs expression was not induced by Puccinia recondite inoculation suggesting that the gene be a constitutive gene with low abundance in wheat. 【Conclusion】In this study, three resistance homology sequence were obtained in TcLr35, which provide the shortcut for the cloning of wheat leaf rust resistance genes.
    Analysis of Correlation Between Seed-Associated Fungi and Seed Vigor of Sweet Corn
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    Scientia Agricultura Sinica. 2006, 39(8):  1565-1570 . 
    Abstract ( 1773 )   PDF (300KB) ( 1590 )   Save
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    【Objective】The aim of this study is to identify the seed-associated fungi of sweet corn and discuss the correlation between seed-associated fungi and seed vigor. 【Method】Seed samples of seven sweet corn cultivars and two dent corn cultivars were collected and analyzed for seed-associated fungi by washing test and PDA test, meanwhile seed vigor of all cultivars were evaluated by rolled towel test.【Result】The result indicated that Fusarium spp., Penicillium spp., Aspergillus spp, Cladosporium sp. were main species of seed associated fungi on seed surface. The rates of seeds with fungi and seeds with Fuasrium of nine cultivars were significantly different. Sweet corn 442 had the highest rate of seeds with fungi, 99.3%, and Nongda108 had the lowest, 4.4%. The mainly isolated fungi inside seeds were Fusarium sp., Penicillium spp., Aspergillus spp, Alternaria spp., Bipolaris spp., Nigrospora sp. Except for Tiandan22, other six cultivars of sweet corn had significant higher rates of seeds with fungi and seeds with Fusarium than that of dent corn cultivars. 【Conclusion】 Based on the analysis of correlation between the rate of seeds with Fusarium and seed vigor, it was presumed that the seed-born Fusarium might have anegative effect on seed vigor.
    Genetic Differentiation of Different Geographical Populations of Bemisia tabaci (Gennadius) Complex
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    Scientia Agricultura Sinica. 2006, 39(8):  1571-1580 . 
    Abstract ( 1606 )   PDF (457KB) ( 1561 )   Save
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    Bemisia tabaci(Gennadius) is a species complex which includes different geographical populations with genetic differentiation. The recent progress on the genetic differentiation of various geographical populations of B.tabaci complex has been introduced. The genetic differentiation has been further analyzed based on the sequences of mtDNA COI and rDNA ITS1 recorded in the world's GenBank. Five groups are defined based on mtDNA COI and rDNA ITS1, including the Asia group, America group, Africa group, Australia group and Biotype B/Mediterranean/Middle Eastern/Northern Africa/Biotype Ms group. There are several ungrouped geographical classifications, such as the Uganda population, Ivory Coast population and Taiwan population. Geographical isolation may be the most important factor that contributed to the genetic differentiation of various geographical populations of B.tabaci. Many populations with biological advantages invaded new regions and caused severe economic losses within human activity. It is necessary to strengthen the research of B.tabaci biotype to prevent the spread of invaded populations and the invasion of potentially dangerous populations.
    SOIL & FERTILIZER·WATER-SAVING IRRIGATION
    Micro-Scale Spatial Variance of Soil Nutients Under Different Plant Communites
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    Scientia Agricultura Sinica. 2006, 39(8):  1581-1587 . 
    Abstract ( 1511 )   PDF (429KB) ( 1623 )   Save
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    【Objective】The Erdos sand land is a typical desertification area in the northern China. The paper is presented on the effects of different desert plant community on the spatial variance of soil nutrients. 【Method】One grass community (Stipa byngeana) and its theoretic succession community (Artemisia sphaerocephala) were selected to compare the effects of plant succession on the distribution of soil nutrients. And the soil organic matter content and the available phosphorus content within a small net under each plant community were analyzed. 【Result】 It revealed that the soil organic matter content and available phosphorus content under the grassland dominated by Stipa byngeana community were higher than those values under the shrub land dominated by Artemisia sphaerocephala community with remarkable difference. The semi-variance of the soil organic matter content under the Stipa byngeana community could be simulated by spherical model (Range a=0.89m), and the semi-variance of the available phosphorus content could be simulated by exponential model (Range a=0.24). It showed that the distribution of soil nutrients under the grass community controlled by the mini plant structure and random factors. The semi-variance of soil organic matter content and available phosphorus content under the shrub community all could be simulated by spherical models, the ranges for organic matter, available phosphorus were 1.5m and 1.40m, which were very near the diameter of the shrub. The geostatic analysis showed the soil organic matter and available P were strongly heterogeneity. 【Conclusion】The distributions of soil nutrients under two kinds of plant communities were obviously different. In the sub-meter scale, the isograms of soil organic matter and available P under the grass community had no regular distributions, but the Isograms of soil nutrients under the shrub community did show as a island of fertility, which higher nutrients content were distributed near the center of the shrub clump.
    A Survey of Lead Concentrations in Vegetables and Soils in Beijing and their Health Risks
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    Scientia Agricultura Sinica. 2006, 39(8):  1589-1597 . 
    Abstract ( 1590 )   PDF (502KB) ( 1750 )   Save
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    【Objective】 To assess the human health risk posed by elevated concentrations of lead in vegetables and to identify lead pollution-tolerant vegetable varieties. The results could be used to guide vegetable safety evaluation and vegetable optimize planting patterns. 【Method】A large scale survey of lead levels in soils and vegetables planted or sold in Beijing was conducted with giving priority to the consumption weight of vegetables and taking account of varieties. Lead health risk was accessed with lead intake from vegetable consumption, and lead pollution-tolerant vegetable varieties were identified with bioconcentration factors (BCFs). 【Result】Lead concentrations in soils ranged from 13.2 to 78.8 mg·kg-1, with arithmetic, median and geometric means of 30.3 and 28.7 mg·kg-1, respectively. Lead concentrations in the edible plant portions ranged from 0.1 to 654.5 μg·kg-1FW, with arithmetic, median and Box-Cox means of 80.9, 51.3 and 48.7 μg·kg-1FW, respectively. In 9.2% of the samples, lead was higher than the Tolerance Limit of Lead in Foods (TLCF) of 0.8 mg·kg-1 fresh weight for pulse and 0.2 mg·kg-1 for other vegetables. The lead concentration in vegetables from Beijing was significantly higher than that of vegetables imported from other places in China, and the lead in the field-grown vegetables was significantly higher than that of vegetables planted in a greenhouse. Results of hierarchical cluster analysis on the BCF of lead in vegetables indicated that the plants sampled could be separated into three groups based on BCF. Round beans trellis (Vigna unguiculata), radish (Raphanus), chili (Capsicum annuum) and bakchoi (Brassica chinensis), which constituted the first group, had the highest BCFs. The second group, which includes cucumber (Cucumis sativus), wax gourd (Beninacasa hispida), Chinese cabbage (Brassica pekinensis), eggplant (Solanum sp.), Chinese green onion, tomato (Lycopersicon esculentum) and cabbage (Brassica oleracea), had higher lead BCFs while leaf beet (Beta vulgaris) and some special varieties vegetables had lower lead BCFs. For adult and children in Beijing, the average ingestion rates of lead from vegetables were 16.6 and 13.6 μg·d-1, respectively. 【Conclusion】 Compared with the background lead concentrations of soil from Beijing, there appeared to be a significant accumulation of lead in soil collected from vegetables plot. Consuming vegetables with elevated lead concentrations may pose a health risk to local residents, particularly the children or ill.
    Preparation and Testing of Cementing and Coating Nano-subnanocomposites of Slow- or Controlled-release Fertilizer
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    Scientia Agricultura Sinica. 2006, 39(8):  1598-1604 . 
    Abstract ( 1448 )   PDF (639KB) ( 1651 )   Save
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    【Objective】To select the cementing and coating agents of slow-or controlled-release fertilizer. 【Method】 The natural kaoline and abandoned foam plastics were used to prepare nano-subnanocomposites using the methods of organic material intercalation, emulsification, and cut at high velocity. Besides, two kinds of nano-subnanocomposites were tested via several instruments including the scanning electron-microscope(SEM), the X-ray diffraction(XRD), the infrared ray spectrum(IR) and the laser granularity in this study. 【Result】(1) The organic material had been intercalated in the layers of kaoline clays, and the natural kaoline was exfoliated into nanometer sized layers. The organic material and clays formed nanocomposites through hydrogen bond combination. (2) The SEM pictures of plastic-starch nano-subnanocomposites showed that many pores and rugas ranged on the surface of film at size of 10-20 nm. 【Conclusion】 These nano-subnanocomposites can be used as the cementing and coating agents of solw- or controlled-release fertilizer.
    Study on Microstructures Characteristics and Nutrition Slow/Controlled-Release Capability of Fertilizer Cores with Different Granulating Techniques and Their Coating CRFs
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    Scientia Agricultura Sinica. 2006, 39(8):  1605-1610 . 
    Abstract ( 1701 )   PDF (1079KB) ( 1259 )   Save
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    【Objective】To date, integrated research of production and consumption of CRFs is lacking. In order to conduct the research, fertilizer cores of CRFs were analyzed to discern improvement of CRF products' controlled-release performance. 【Method】An electron scanning microscope was used to study the core-coating microstructure of 4 fertilizer cores with different granulating processes and their coated CRFs. The influence of different granulating techniques on controlled release performance was analyzed according to a N leaching experiment of 2 CRFs with different cores. 【Result】When the air-cooling core and the disc-core were between the oil-cooled and drum cores, the oil-cooled-core had the smoothest surface, and the drum-core had a porous and coarse surface. While the tower-core and disc-core were between the oil-cooled and drum cores, the oil-cooled-core was very tidy and the drum core was loose. With the tower-core and disc-core in between, the oil-cooled-core had very high compactness in core- coating, the drum core had an obvious gap between core-coating. A soil-column leaching experiment showed that CRF with an oil-cooled-core had a much lower accumulated N leaching rate than that of CRF with drum-core. 【Conclusion】The performance of controlled-release was closely related to different core-coating microstructures. This paper analyzes and discovers the contribution of a CRF core to nutrient release capability improvement.
    HORTICULTURE
    Effect of Different Scions/Rootstocks on Quality of Cucumber Fruits in Greenhouse
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    Scientia Agricultura Sinica. 2006, 39(8):  1611-1615 . 
    Abstract ( 1484 )   PDF (262KB) ( 1490 )   Save
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    【Objective】An experiment was conducted to investigate the effect of different scions/rootstocks on the quality of greenhouse cucumber fruits. 【Methed】Scions of three cucumber (Cucumis sativus L.) varieties Jinyou No.1, Shannong No.6 and Xintaimici were grafted on rootstocks of figleaf gourd (Cucurbita ficifolia) and Sintozwa (Cucurbita maxima × C. moschata) to draw comparison between cucumber and their fruits. 【Results】 The water contents had no obvious differentiations. The contents of soluble sugar, Vc, amino acid, particularly Glu and Asp, and the characteristic cucumber flavor ((ZE)2,6-nondienal and 2, 6-nonadienol) all decreased. The NR activity was remarkably reduced. With the exception of the increased levels of Fe and Zn in the cucumber's own fruits, the contents of nitrate, tannin titrable acid, Ca, Mg, Fe and Zn all distinctly increased in the grafted cucumber. In terms of producing quality fruits, Sintozwa was more effective than figleaf gourd as rootstock. For cultivation periods, fall produced higher quality cucumber fruit than those of spring. 【Conclusion】The key factor in decreasing the negative impacts of grafting resides in selecting the appropriate rootstock.
    Cytochemical Localization and Changes in Activity of Plasma Membrane Ca2+-ATPase in Young Grape (Vitis vinifera L. cv. Jingxiu) Plants During Cross Adaptation to Temperature Stresses
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    Scientia Agricultura Sinica. 2006, 39(8):  1617-1625 . 
    Abstract ( 1389 )   PDF (1272KB) ( 1306 )   Save
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    【Objective】The aim of the experiment is to explore the mechanism of cross adaptation to different temperature stresses in the plants.【Method】Leaves from one-year-old young grape (Vitis vinifera L. cv. Jingxiu) plants were used as experimental materials in this experiment. The changes of activity of plasma membrane Ca2+-ATPase both in chilling-treated plants after heat acclimation (HA, 38℃/10 h) and heat-treated plants after cold acclimation (CA, 8℃/2.5 d) were analyzed with biochemistry assay and electromicroscopic-cytochemical assay in which cerium trichloride (CeCl3) precipitation method was adopted. 【Result】The plasma membrane Ca2+-ATPase activity was increased by HA or CA pretreatments. There was no obvious change in tonoplast Ca2+-ATPase activity after HA or CA. However, the stability of Ca2+-ATPase was enhanced under the subsequent cross-temperatures stresses, and the activity was always kept at higher level than that of control. 【Conclusion】This result from biochemistry assay agreed with the observation through the electro-microscopic technology, which suggested that plasma membrane Ca2+-ATPase was involved in the chilling resistance induced by heat HA and the thermotolerance of grape plants induced by CA and almost had the same regulating mechanism.
    Storage and Remobilization of Nitrogen by Chinese Jujube (Z. jujuba Mill. var. inermis Rehd) Seedling as Affected by Timing of 15N Supply
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    Scientia Agricultura Sinica. 2006, 39(8):  1626-1631 . 
    Abstract ( 1558 )   PDF (226KB) ( 1207 )   Save
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    【Objective】Winter jujube orchard nitrogen (N) management should aim at increasing N reserves, meeting the tree growth requirement. Fertilization strategies should maximize the efficiency of fertilizers, including the choice the optimal timing of N supply.【Method】15N-urea was applied to winter jujubes on 'jinsixiaozao' jujubes rootstock to evaluate the effect of application timing on N storage and remobilization in mature trees in pot culture. The treatments consisted of ground application before budding (BB), fruit core-hardening stage (FCH) and fruit rapid-swelling stage (FRS).【Result】Nitrogen use efficiency of treatments were significantly different, which were 2.42% (BB), 9.77% (FCH), 9.01% (FRS) in the dormant and 5.20% (BB), 16.16% (FCH), 10.30% (FRS) in the following full bloom. N supply in the pre-harvest helped to increase trees N reserves and then relocate to the new growth organs following year. The largest amount of 15N was detected in the roots and trunks. In all treatment the partition rates were highest in coarse roots, which were 30.43% (BB), 38.61% (FCH), 40.62% (FRS), respectively. 15N stored in roots and trunks were used by jujube trees to sustain new growth in the following full bloom. 15N applied before budding resulted in lower Ndff% in perennial organs (trunks and coarse roots) sampled in the proceeding full bloom, but fine roots had highest Ndff% (1.28%). Other organs recovered a similar amount of Ndff%. In contrast, FCH and FRS treatment led to higher Ndff% (4.01%-5.15%) in the new growth organs (new branches, deciduous spurs, leaves and followers), but lower Ndff% in perennial branches (1.49%-2.89%).【Conclusion】With the delay of 15N-urea application time, 15N increased the partitioning to roots. FCH treatment increases N storage in perennial organ during winter, which should be remobilized to sustain new growth the following spring.
    Screen of Dominating Microbial Species Isolated From Tibetan Kefir Using an Integrated Approach of PCR-DGGE and Culture-Dependent Methods
    ,,HanHu Jiang
    Scientia Agricultura Sinica. 2006, 39(8):  1632-1638 . 
    Abstract ( 1781 )   PDF (536KB) ( 1347 )   Save
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    【Objective】To screen dominating microbial species isolated from Tibetan Kefir and develop pure-culture starter. 【Method】PCR-DGGE and traditional culture-depending methods were combined to examine the microbial community of Tibetan kefir. 【Result】 Four bands in the DGGE profiles of total bacterial DNA of Tibetan kefir were not recovered by cultivation. Conversely, two bacterial species did not exhibit bands in DGGE fingerprints of total bacterial DNA of Tibetan kefir. 150 strains isolated were screened and grouped by PCR-DGGE, eight lactic acid bacteria and five yeasts were obtained. Comparison of 16S rDNA (bacteria) and 26S rDNA (yeast) partial sequence similarity revealed that the dominating microbial species of Tibetan kefir were Leuconostoc mesenteroides, Lactococcus lactis, Lactobacillus kefiri, Lactobacillus casei and Kluyveromyces marxianus, Saccharomyces unisporus, Saccharomyces cerevisiae and Candida humilis were dominating during last fermentation. 【Conclusion】 An effective microbial screening technology based on molecular microbiology was established in this study, providing theoretical basis and rich microbial resources for the development of Tibetan Kefir pure-culture starter.
    ANIMAL SCIENCE·VETERINARY SCIENCERE·SOURCE INSECT
    Cloning and Sequence Analysis of Yak Heart Fatty Acid-Binding Protein (H-FABP) Gene
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    Scientia Agricultura Sinica. 2006, 39(8):  1639-1650 . 
    Abstract ( 2072 )   PDF (559KB) ( 1497 )   Save
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    【Objective】The yak heart fatty acid-binding protein (H-FABP) gene was cloned and sequenced. This was then compared to the deduced amino acid sequence with the homologous H-FABP gene. It was also compared with the protein sequence of the H-FABPs in other species (including cow, sheep, goats, pigs, human, rats, mice, chicks and zebra-fish) retrieved from the GenBank . These comparisons were performed in order to provide a theoretical foundation for further research of the correlation of yak H-FABP gene and meat quality, molecular breeding, location and expression.【Method】The yak H-FABP gene was amplified using particular primers, cloned by T-A method and sequenced, based on this the nucleotide and amino acid sequences among different species were compared and analyzed by RepeatMasker、DNAMAN4.0、BioEdit4.8.10、Clustal W1.81 i.e, bio-softs.【Result】The number of exons and introns of yak H-FABP gene (GenBank Accession No: DQ026674) were as same as those in cow, sheep, goats, pigs, human, rats, mice, chicks and zebra-fish. They had 4 exons and 3 introns. The size of CDS sequence of the yak H-FABP gene, encoding 133 amino acid, was 402 bp. The size of exon I, exonⅡ, exonⅢ and exonⅣ was 73 bp, 173 bp, 102 bp and 54 bp respectively; while the size of intron I, intronⅡand intronⅢ was 3 460 bp, 1 892 bp and 1 495 bp respectively. The junction sequence of exons and introns of yak H-FABP gene was in accordance with the law of gene composition. The rate of the repetitive sequence was 13.07% in the nucleotide sequence of yak H-FABP gene. Five repetitive elements were found in the intronⅠ, including a SINE/Artiodactyls element, a SINE/MIR3 element, a SINE/Bov-tA1 element and two SINE/MIR elements. No repetitive element was found in intronⅡ. Three repetitive elements were found in intron3, including a SINE/MIR element, a LINE/L2 element and a SINE/Artiodactyls element. The rate of the repetitive sequence was 11.85% for SINEs, 6.44% for MIRs and 1.22% for LINEs respectively. In addition, LINE1, BovB/Art2, L3/CR1 repetitive elements, LTR anti-transcription element and DNA transposing element were not found in this sequence. The nucleotide sequence of the coding region and deduced amino-acid sequences among different species were quite conservative. The homology rates of nucleotide sequences of the coding region of H-FABP gene between the yak and cow, sheep, goat, pig, human, rat, mouse, chick and zebra-fish were 99.8%, 97.8%, 97.0%, 92.8%, 88.8%, 83.3%, 83.1%, 76.4%, 68.7% respectively, while the homology rates of amino-acid sequences were 100%, 96.9%, 96.9%, 92.4%, 88.7%, 85.7%, 85.7%, 77.4%, 69.9% respectively. 【Conclusion】The yak H-FABP gene had 4 exons and 3 introns. The size of CDS sequence of the yak H-FABP gene, encoding 133 amino-acid, was 402 bp. The size of exon I, exonⅡ, exonⅢ and exonⅣ was 73 bp, 173 bp, 102 bp and 54 bp respectively; while the size of intron I, intronⅡand intronⅢ was 3 460 bp, 1 892 bp and 1 495 bp respectively. There were many repetitive elements in the nucleotide sequence of yak H-FABP gene, and the junction sequence of exons and introns was accordance with the law of gene composition. The nucleotide sequences of the coding region and deduced amino acid sequences between yak and cow, sheep, goats, pigs, human, rats, mice, chicks and zebra-fish were quite conservative.
    Immunization in Pigs Vaccined with DNA Encoding PRRSV GP5
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    Scientia Agricultura Sinica. 2006, 39(8):  1651-1658 . 
    Abstract ( 1704 )   PDF (482KB) ( 1211 )   Save
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    【Objective】The aim is to analyze the immune responses and the effects of the cytokines induced by GP5 recombinant plasmids of PRRSV. 【Method】SPF piglets were immunized with DNA recombinant plasmids pCI-GP5 which expresses PRRSV GP5 by co-administration of pcDNA-IFN- , pcDNA-IL-2 and pcDNA-IL-4 for three inoculations. The vaccinated pigs were challenged intranasally with PRRSV BJ-4. 【Result】DNA immunization with pCI-GP5 resulted in the production of both neutralizing antibodies (1:19.2) and cellular immune responses two weeks after the third immunization. The pCI-GP5 showed significantly better protection from the PRRSV challenge compared with the control plasmid. The protection was characterized with a decrease of 39% PRRSV-positive tissues. In addition, the co-administration of pcDNA-IL-4 increased the immune response induced by pCI-GP5. This immune response was characterized by a significant enhancement of a lymphoproliferative response and a higher percentage of CD4-CD8+T cell, showing a higher viral neutralization titer of 1:35.5, a lower percentage of PRRSV-positive tissues and a significantly decreased frequency of viraemia (a drop of 64% and a drop of 17%, respectively, compared with the control group). Delivery of pcDNA-IL-2 paired with pCI-GP5 resulted in enhanced cellular immune responses, remarkably reduced percentage of PRRSV-positive tissues and frequency of viraemia (a drop of 59% and a drop of 50%, respectively, compared with the control group). In contrast, the co-administration of pcDNA-IFN- had no adjuvant effects. 【Conclusion】The results indicated that IL-4 and IL-2 could be used as adjuvant of PRRSV DNA vaccine.
    Screening, Cloning and Immunological Efficiency of SjPP, a Novel Schistosoma japonicum Gene
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    Scientia Agricultura Sinica. 2006, 39(8):  1659-1666 . 
    Abstract ( 1846 )   PDF (342KB) ( 1060 )   Save
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    【Objective】 The aim of the experiment is to screen and clone antigen genes of Schistosoma japonicum specific to the sera of Microtus fortis and study the protective efficiency. 【Method】A cDNA library of Schistosoma japonicum adult worm was immunologically screened with the sera from Microtus fortis infected with the schistosome. Then mice were immuned with DNA vaccine of SjPP to evaluate the immunological protective efficiency. 【Result】(1) Five positive clones, mfs-1, mfs-2, mfs-3, mfs-4 and mfs-5, were obtained and their sequences were deposited with GenBank under accession No. BE974942, BE974943, BE974944, BE974945, BE974946 respectively. (2) A full length cDNA fragment containing a complete open reading frame coding 302 amino acid sequences (Mr=34.7kD, pI=5.51) was amplified. Sequence analyses revealed that it was a novel gene which deduced amino acid sequence contain a conserve sequence (LRGNHE) of serine/threonine specific protein phosphatases, as well as a binding site (SAPNYC) of the phosphatase's specific inhibitor okadaic acid. The gene was showed high homology to other protein phosphatases such as human PP6 (72%), PP4C (59%), rat PPV (71%), fruit fly PPV (70%), fission yeast ppe1 (63%), budding yeast sit4p (61%) and was named as SjPP. (3) Compared with those of the blank control group, 23.91% reduction in mean hapetic tissue egg count and 31.91% reduction in mean faecal egg count were recovered in the mice injected with the recombinant plasmid pCMV-Script/SjPP. 【Conclusion】(1) A novel antigen gene of Schistosoma japonicum, SjPP, was cloned and identified. (2) The partial protection was obtained in the mice vaccinated with the DNA vaccine pCMV-Script/SjPP.
    Mutations of gyrA and parC in Fluoroquinolones-Resistant Escherichia coli Strains Isolated from Animals,Farmers and Environment
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    Scientia Agricultura Sinica. 2006, 39(8):  1667-1673 . 
    Abstract ( 1769 )   PDF (402KB) ( 1141 )   Save
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    【Objective】To detect mutations of gyrA and parC in 72 Escherichia coli strains isolated from human feces, animal feces and the environment.【Method】MICs of ciprofloxacin or enrofloxacin for 72 isolates were determined by an agar dilution test with standard strain ATCC25922 as the control. The mutations in the quinolone resistance-determining regions (QRDRs) of the gyrA and parC genes were analyzed by PCR and sequencing. 【Result】Amino acid substitutions (number of strains) found in 63 mutants were Ser83→Leu(62)and Asp87→Asn(52),Asp87→Tyr(2),Asp87→His(2)in GyrA and Ser80→Ile(47),Ser80→Arg(2)and Glu84→Val(3),Glu84→Lys(4),Glu84→Gly(5),Glu84→Ala(1)in ParC.No amino acid changes in GyrA or ParC were detected when strains MIC of ciprofloxacin were under 0.125 μg·ml-1.A single substitution in GyrA was found in the strains whose MIC of ciprofloxacin ranged from 0.125 to 0.25μg·ml-1.Double substitutions in GyrA or one in GyrA with one in ParC were found in the strains with MICof ciprofloxacin ranging from 0.5 to 32 μg·ml-1.A double changes in GyrA and a single change in ParC were found in strains with MIC of ciprofloxacin ranging from 4 to 128 μg·ml-1.Double changes in GyrA and double changes in ParC were found in strains with MIC of ciprofloxacin ranging from 16 to 128 μg·ml-1.【Conclusion】A variety of amino acid changes in GyrA and ParC were detected in the fluoroquinolone-resistant E. coli isolates from different origin.A correlation was found between the number of changes in the QRDR of GyrA and ParC and the resistance level to fluoroquinolone in E. coli strains.
    The Sequence and Phylogenetic Analysis of the Ribosomal RNA Gene and the ITS Region of Nosema antheraeae
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    Scientia Agricultura Sinica. 2006, 39(8):  1674-1679 . 
    Abstract ( 1757 )   PDF (340KB) ( 1396 )   Save
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    【Objective】This paper examines the sequence and organization of the ribosomal RNA gene, the ITS region of Nosema antheraeae, and present molecular biological evidence of Nosema antheraeae taxonomy. 【Method】To obtain the phlogenetic tree and sequence distance, specific primers were used for PCR amplification, then clone and nucleotide sequences were aligned using Clustal W of DNAStar software. 【Result】The outcome entailed a full small subunit rRNAs (SSU rRNA) gene, the internal transcribed spacer (ITS), 5S rRNA gene and part of the large subunit rRNAs (LSU rRNA) gene of Nosema antheraeae. 【Conclusion】The organization of the ribosomal RNA gene of Nosema antheraeae follows a special organizational pattern: LSU-ITS1-SSU-ITS2-5S. Elucidating phylogenetic relationships of microsporidia species by combining information from SSU rRNA and ITS sequence is a new experiment.
    RESEARCH NOTES
    Distribution of Dwarfing Genes Rht-B1b and Rht-D1b in Chinese Bread Wheats Detected by STS Marker
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    Scientia Agricultura Sinica. 2006, 39(8):  1680-1687 . 
    Abstract ( 1679 )   PDF (526KB) ( 1485 )   Save
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    【Objective】 Understanding the distribution of dwarfing genes in Chinese wheat will be crucial for yield improvement.【Method】A total of 239 Chinese wheat cultivars and advanced lines from major wheat regions were detected by STS markers to understand the distribution of the dwarfing genes Rht-B1b (Rht1) and Rht-D1b (Rht2). 【Result】The PCR-based markers could be used to test the presence of Rht-B1b and Rht-D1b in wheat cultivars. The average frequency was 24.3% for Rht-B1b gene and 46.9% for Rht-D1b gene, respectively. Frequencies in Northern Winter Wheat Zone, Yellow & Huai River Facultative Winter Wheat Region, Middle & Low Yangtze Valley Winter Wheat Region, Southwestern Winter Wheat Region, Northeastern Spring Wheat Region, Northern Spring Wheat Region, Northwestern Spring Wheat Region and Xinjiang Winter-Spring Wheat Region were 25.8%, 28%, 42.3%, 8.3%, 0%, 9.1%, 25% and 62.5% for Rht-B1b gene, and 35.5%, 69%, 23.1%, 38.9%, 0%, 72.7%, 37.5% and 12.5% for Rht-1Db gene, respectively. 【Conclusion】Molecular markers and pedigree information confirmed that Rht-B1b is from St2422/464 and Norin 10, Rht-D1b is from Norin 10, Suwon 86, Huixianhong, and Youbaomai.
    Analysis of Heterotic Patterns of Maize Hybrids Used in
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    Scientia Agricultura Sinica. 2006, 39(8):  1689-1696 . 
    Abstract ( 1683 )   PDF (374KB) ( 1488 )   Save
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    【Objcetive】The purpose of this study is to analyze the heterotic pattern of maize hybrids used in Henan Province. 【Method】Simple sequence repeat (SSR) was used to study genetic diversity of the parents of some maize hybrids approved in China′s Henan Province and some other inbred lines. A total of 143 SSR primer pairs were tested, from which 95 primer pairs that evenly distributed on maize genome were selected for genotyping the inbred lines. Cluster analysis of the inbred lines was performed by using UPGMA method. The heterotic patterns of hybrids approved in Henan Province as well as introduced ones were also analyzed based on the planting areas of the hybrids in Henan Province from 1981 to 2003. 【Result】 The results showed that: (1) most of the inbred lines used for making hybrids approved in Henan could be divided into six groups, i.e. Reid, Tem-tropic, SiPT, LvDHG, Lancaster and Synthetic, based on Nei-Li's genetic distances, which agreed with the result from pedigree analysis; (2) there were 12 heterotic patterns employed for making of hybrids widely used in Henan for maize cultivation, among which Reid × SiPT and Lan × LvDHG were prominent patterns. The hybrids from the two patterns occupied 47 % of total cultivation in Henan Province, among which 26.47% was for Reid × SiPT and 20.62% for Lan × LvDHG. Other patterns like Reid × LvDHG was 9.41% and Tem-tropic × others (including Synthetic and Reid) 9.07%. The later is a new pattern with an increasing utilization and is worthwhile to be exploited. 【Conclusion】Of the 12 heterotic patterns, Reid × SiPT and Lan × LvDHG were mainly used ,which occupied about a half of the total planting areas in Henan in the past 23 years.
    Effect on Soil Moisture, Nutrient and Weed Control in Arid Farmland by Shallow Tillage
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    Scientia Agricultura Sinica. 2006, 39(8):  1697-1702 . 
    Abstract ( 1425 )   PDF (207KB) ( 1381 )   Save
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    【Objective】In order to provide the basis of output improvement and arid farmland development, reduce the consumption of soil moisture and nutrient and control the weed and utilize natural precipitation.【Method】Changes of the quantity of weed seeds, soil moisture and nutrient by shallow tillage accompanied herbicide and deep tillage had been studied for 3 years. 【Result】 85%-90% weed seeds which fell in 0-10 cm soil layer were controlled easily by shallow tillage 2 days after autumn harvest, and weed seeds were 1.8% and 4.1% respectively below 10 cm soil layer after 5 and 10 days. 80.2% of weed seeds were in 10-30 cm soil layer by deep tillage, and 19.8% were in 0-10 cm. It was difficult to control weeds as few seeds could sprout and grow below 10 cm soil layer. Accompanied with herbicide, the quantity of weed seeds in tilth decreased averagely by 75.4% in shallow tillage, and by 27.3% in deep tillage. 50% of the cost of machine cultivation and the quantity of irrigation water were saved by shallow tillage. And it could loose soil surface so that hold the soil moisture. Moreover, there was no significant influence on soil moisture and nutrient. However, it should be cultivated heavily or not in use for one year after 2-3 years of shallow tillage. 【Conclusion】 Farmland of harvested by deep tillage is difficult to eradicate below 10cm soil layer, and result in soil erosion severity, water deficiency, meanwhile effect sprout and seeding this is one of the main causes of soil dry However, weed control by shallow tillage supports the sustainable development of dry farming.
    Effects of Extracts of Tupistra chinensis on Mycelia Growth of Peronophythora litchii and Storage Life of Litchi Fruit
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    Scientia Agricultura Sinica. 2006, 39(8):  1703-1708 . 
    Abstract ( 1532 )   PDF (295KB) ( 1264 )   Save
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    【Objective】To exploit plant-derived antifungal substances as an alternative strategy to control post-harvest diseases of fruits and vegetables.【Method】The MeOH extract of the rhizomes of Tupistra chinensis was fractioned sequentially with petroleum ether, EtOAc and n-BuOH. The antifungal activities of the MeOH extract and its fractions against Peronophythora litchii were evaluated both in vitro and in vivo using agar plate tests and intact fruit inoculated with Peronophythora litchii. Storage experiments of litchi fruits treated with the MeOH extract and its fractions were carried out.【Result】The EC50 values of the MeOH extract, its EtOAc fraction and n-BuOH fraction inhibiting the mycelia growth of P. litchii were 1598.10, 662.86 and 1147.31 ?g?ml-1, respectively. Dipping litchi fruit in the MeOH extract, its EtOAc fraction or n-BuOH fraction solution resulted in a significant reduction of P. litchi inoculation infection. Additionally, the use of the above extract or fractions was significantly effective in reducing natural incidence of diseases and retarding quality deterioration of litchi fruits during storage.【Conclusion】The MeOH extract of T.chinensis, its EtOAc fraction and n-BuOH fraction were distinct active against Peronophythora litchii both in vitro and in vivo. Treatment of litchi fruits with the extract or fractions had beneficial storage effects.
    AFLP Analysis of Genetic Diversity of 30 Tree Peony (Paeonia suffruticosa Andr.) Cultivars
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    Scientia Agricultura Sinica. 2006, 39(8):  1709-1715 . 
    Abstract ( 1411 )   PDF (424KB) ( 1324 )   Save
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    【Objective】Investigation of the tree peony's genetic diversity (Paeonia suffruticosa Andr.) is significant in utilizing its germplasm resources and cultivating new varieties. 【Method】The phylogentic relationships among 30 tree peony cultivars were analyzed using AFLP to study the genetic diversity with eight AFLP primer combinations (M+3 and P+3) . 【Result】Among the 1123 bands detected,965 bands were polymorphic and specific bands were found in all 30 tree peony cultivars. The high ratio of polymorphic bands (86%) observed in this study indicate abundant genetic diversity among tree peony cultivars. 【Conclusion】Our results suggest that the 8 pairs of prime combinations could be used to distinguish between all cultivars being tested. Results of cluster analysis showed that the classification based on AFLP markers of cultivars was consistent with their origin.
    Construction and Identification of a Recombinant Pseudorabies Virus Expressing ORF2 Gene of Porcine Circovirus Type 2
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    Scientia Agricultura Sinica. 2006, 39(8):  1716-1722 . 
    Abstract ( 1608 )   PDF (438KB) ( 1123 )   Save
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    【Objective】In this paper, a recombinant virus expressing ORF2 gene of PCV2 using pseudorabies virus as vector. 【Method】The ORF2 gene of porcine circovirus type 2 was inserted into the universal transfer vector deleting gG of pseudorabies virus to generate the recombinant transfer plasmid. The genomic DNA of PRV TK-/gG-/LacZ+ strain and pgGORF2 were co-infected into IBRS-2 cells. Then the recombinant virus TK-/gG-/ORF2+ was selected and its biological characteristic was measured.【Result】The recombinant virus was selected by PCR with ORF2 gene and LacZ gene primers respectively and the PCV2 ORF2 gene had been inserted into the genome of TK-/gG-/LacZ+ strain identified by Southern blotting. The results of indirect immunofluorescene assay (IFA) and Western blotting indicated that the ORF2 gene was expressed successfully. Propagation of the recombinant virus in cells was corresponding to the parent strain. Animal experiments showed that the recombinant virus TK-/gG-/ORF2+ was safe to mice and could induce the specific antibodies against expressed ORF2 protein. 【Conclusion】 The recombinant pseudorabies virus was constructed successfully, and the expressed ORF2 protein had immunogenicity.
    Effect of Antibacterial Peptide Extracted from Pig Small Intestine on Growth-Enhancing and Approach to the Mechanism in Chickens
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    Scientia Agricultura Sinica. 2006, 39(8):  1723-1571 . 
    Abstract ( 2580 )   PDF (801KB) ( 1789 )   Save
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    【Objective】 To study the effect of antibacterial peptide extracted from pig small intestine on the growth performance and growth mechanisms in chickens. 【Method】Sixty 7-day-old chickens with similar weight body were separated into experimental and control groups at random. One-tenth ml (100 μg·ml-1) of antibacterial peptide (ABP) was administered intramuscularly into each experimental group chicken at the age of 7, 14, 21, 28, 35, 42 days, One-tenth ml of sterile saline into control group's chicken at the same age, respectively. Two groups of chickens were fed under the same conditions for 6 weeks. The villus length, mucosa thickness and villus/crypt (V/C) value of duodenum and jejunum were determined at the age of 7, 49 days, respectively. 【Result】 The average daily weight gain of the experimental group chickens (13.54±0.20) g was significantly higher than that of the control group chickens (11.10±0.19) g (P<0.01), and the feed/weight-gain ratio of the experimental group chickens (2.27±0.04) was significantly lower than that of the control group chickens (2.60±0.05) (P<0.01). The villus length and V/C value of duodenum and jejunum of the experimental group chickens were higher than those of the control group chickens at the age of 49 days (P<0.05). The mucosa thickness of duodenum and jejunum of experimental group was of no significant difference compared with the control group (P>0.05).【Conclusion】The antibacterial peptides could improve the structure of duodenum and jejunum and enhance the growth performance and feed conversion ratio.