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Table of Content

    20 September 2004, Volume 37 Issue 09
    TILLAGE & CULTIVATION·PHYSIOLOGY & ECOLOGY
    Study on Non-flooding Farming Technique in Irrigated Paddy Field-Physiological and Developmental Characteristics of Rice
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    Scientia Agricultura Sinica. 2004, 37(09):  1249- . 
    Abstract ( 954 )   PDF (526KB) ( 318 )   Save
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    Sub-species hybrid rice Liangyoupeijiu (two-line hybrid rice) and Xieyou-9308 (three-line hybrid rice) were selected as testing materials. The physiological characteristics of rice growth and development were studied by comparing the conventional flooding rice farming CFRF)with non-flooding rice farming ( NFRF). Results of the experiment showed that there were no differences as total leaf number and panicle initial development were concerned. At the same time, the period from sowing to heading was 4-8 days less of the NFRF than the CIRF, showing that the NFRF had comparative shorter reproductive duration. Larger total leaf area per hill, leaf area index and heavier root dry weight were observed on the NFRF. At the same time, the NFRF facilitates heavier and deeper root system. However, the NFRF is access to form a high biomass colony by large individual plant, and the dry matter accumulated after heading accounted for 40% of the total dry matter. Several disadvantages were also observed on the NFRF technique: (1) Less amount of root exude with lower zeatin content, and a lower respiration rate. (2) The flag leaf photosynthesis rate from filling stage to ripening stage decreased, and stomatal resistance increased as compared to traditional flooding irrigation. Some possible ways for increasing photosynthesis rate by improving physiological activity of plant during filling stage were also discussed.
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES
    Studies of Multiple-Allelic Polymorphism of Dominant Dwarfing Genes in Wheat
    Scientia Agricultura Sinica. 2004, 37(09):  1251-1260 . 
    Abstract ( 1011 )   PDF (959KB) ( 623 )   Save
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    Dwarfing breeding of wheat in the world is confined to the exploitation of recessive dwarfing sources. None of the dominant dwarfing sources discovered in common wheat (Triticum aestivum L.) has found wide exploitation in wheat breeding due to the extreme dwarfness of their plants (20-55 cm). It was found that some stable mutant lines with plant height enhanced to different extents could be obtained in large populations derived from the stock seeds of the dominant dwarfing sources 'Aibian 1' carrying Rht10 on 4DS and being 20-55 cm in height and 'Aisu 3' carrying Rht3 on 4BS and being 55 cm in height, or from their descendants of induced mutation treatments, or from the segregating descendants of their crosses with mid- or tall-statured genotypes. Subsequently, these mutation-derived lines differing in plant height with near isogenic lines were studied and it was observed that the character of their enhanced plant breeds true, each carries a semi-dominant dwarfing gene for a definite height and that as the plant height of the mutation-derived lines rises, the yield-contributing characters of their near isogenic lines are significantly improved. When test crosses with marker genes and physiological and biochemical genetic marker tests were performed to re-localize the semi-dominant dwarfing genes carried by the mutation-derived lines, it was confirmed that they share common loci with Rht10 and Rht3 and that they are all mutation-derived multiple alleles. It is thus speculated that dominant dwarfing genes are of "multiple-allelic polymorphism", in other words, dominant dwarfing genes, which are ultra-dwarfing, are liable to develop by mutation into a group of multiple alleles with plant height enhanced to different extents and some may have a height close to the ideal plant height for wheat breeding.
    Cytological Observation on Microspore Genesis of WBMs - a New Line of S-CMS Maize
    Scientia Agricultura Sinica. 2004, 37(09):  1261-1264 . 
    Abstract ( 1122 )   PDF (726KB) ( 642 )   Save
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    WBMs is a cytoplasmic male sterile line developed by Huazhong Agricultural University. The microspore genesis of WBMs was observed by optical and electron microscope. The results indicated that the microspores of WBMs could normally develop before the middle stage of microspore, but some of microspores began degradation in the late stage, and others could normally develop until the bi-nuclear pollen stage, sequentially, the pollen grain collapse suddenly, as a result, shrunken pollens were formed. The process of microspore abortion of WBMs was similar to Tangxu CMS of S group which pollen abortion is happened in late developing stage and the normally somatic activity such as tapetal cell. The sterility of WBMs was typical gametophyte sterility. According to its cytological characters, cytoplasm of WBMs can be preliminarily classified into S group of maize CMS.
    Effect of Allelic Variation at the Glu-1 and Glu-3 Loci and Presence of 1BL/1RS Translocation on Pan Bread and Dry White Chinese Noodle Quality
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    Scientia Agricultura Sinica. 2004, 37(09):  1265-1273 . 
    Abstract ( 1148 )   PDF (785KB) ( 822 )   Save
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    High molecular weight glutenin subunitins (HMW-GS), low molecular weight glutenin subunits (LMW-GS), and 1BL/1RS translocation play an important role in determining the processing quality in common wheat. 80 and 78 cultivars and advanced lines in trial Ⅰ and trial Ⅱ were sown in two and four environments, respectively. They were used to investigate the effect of HMW-GS, LMW-GS and 1BL/1RS translocation on dough rheological characteristics, pan bread and dry white Chinese noodle quality. Glu-B1, Glu-D1 and Glu-B3 loci play a determinant role in dough rheological characteristics, pan bread and dry white Chinese noodle quality and Glu-A3 locus has slight contribution to them. For gluten strength and loaf volume, at Glu-A1 locus, 1>2*>N;at Glu-B1 locus,7+8>7+9;at Glu-D1 locus,5+10>4+12>2+12;at Glu-A3 locus;Glu-A3d>Glu-A3c> Glu-A3a; at Glu-B3 locus, Glu-B3d>Glu-B3f>Glu-B3b>Glu-B3j. For extensibility and noodle score, at Glu-A1 locus,1>N;at Glu-B1 locus,20>7+9>7+8; at Glu-D1 locus,4+12>5+10≥2+12;at Glu-A3 locus,Glu-A3c≥Glu-A3d>Glu-A3a;at Glu-B3 locus, Glu-B3b≥Glu-B3f>Glu-B3d>Glu-B3j. Lines carrying 1BL/1RS translocation show significantly delerious effect on dough rheological characteristics, pan bread, and dry white Chinese noodle quality.
    TILLAGE & CULTIVATION·PHYSIOLOGY & ECOLOGY
    Study on Estimating the Contents of Crude Protein and Crude Starch in Rice Panicle and Paddy by Hyperspectra
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    Scientia Agricultura Sinica. 2004, 37(09):  1282- . 
    Abstract ( 1197 )   PDF (378KB) ( 894 )   Save
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    The contents of protein and starch in rice are two of the indices to evaluate the nutrition and taste quality of rice. Normal determinations of their contents by chemical methods are of high expense and time consuming. The hyperspectral reflectances of the canopy and panicle of 5 rice varieties were measured by a ASD FieldSpec Pro FRTM in field and indoor under 3 nitrogen application levels in mature process, and that of paddy measured too. The contents of crude protein and crude starch in panicle and paddy were determined. The contents of crude protein and crude starch in panicle were significantly correlated to the canopy spectra and their first derivative spectra at some wave bands, and also significantly correlated to the spectra of panicle powder and their first derivative spectra at some wave bands. The squared multiple correlation coefficients (R2 ) were about 0.7. The crude starch content was negative correlative to the crude protein contents in paddy. They were very significantly correlated to the paddy spectra and their first derivative spectra at some wave bands. This indicated that it was feasible for estimating the contents of crude protein and crude starch in panicle and paddy by hyperspectral remote sensing. It would provide a basis for monitoring rice quality by remote sensing.
    Growth Analysis on the Process of Grain Filling in Hybrid Wheat 901 and Its Parents
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    Scientia Agricultura Sinica. 2004, 37(09):  1288-1292 . 
    Abstract ( 886 )   PDF (420KB) ( 821 )   Save
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    Using Matlab process, the grain filling process of hybrid wheat 901 and its parents was fitted by Richards equation on computer in order to study the characteristics of grain filling in hybrid wheat 901. The active grain growth period of hybrid wheat 901 was 6 days longer than that of Shan 229, its final grain weight (43.7 g?1000-grain-1) was higher than that of Shan 229 (36.3 g?1000-grain-1). N values of 901 and R205 were both less than 1, their grain growth was fast in the early filling stage, slower in the middle-late stage. N value of Shan 229 was > 1, its growth was slow in the early stage and fast in the middle stage. The duration of early stage of 901 was short and the duration of middle-late stage of 901 was longer. The situation of Shan 229 was totally reversed. In parents, the father plant R205 was similar with hybrid wheat 901, its mother plant K3314A was similar with Shan 229. It was also found that Richards equation was more suitable for fitting the grain filling process of wheat than Logistic equation.
    Some Eco-physiological Characteristics at Rt-Rs Stage in relation to Soybean Yield Differing in Maturities
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    Scientia Agricultura Sinica. 2004, 37(09):  1293-1300 . 
    Abstract ( 1115 )   PDF (424KB) ( 927 )   Save
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    Digital plant canopy imager and photosynthesis analyzer system were used to analyze characteristics of canopy structure, photosynthetic physiology and micro-environmental factors at R4-R5 stage in different yielding soybean cultivars or lines with different maturities. The results showed that the common traits of high yielding soybean were high in LAI, uniform in foliar distribution in all horizontal directions, less variance of photosynthetic rate between top and bottom leaves in canopy and relatively high photosynthetic rate of the whole canopy to enhance photosynthetic productivity. Thus, pod number, seed number and seed weight per plant,especially pod and seed number in top and medium canopy increased. The characters of high yielding colony in different maturing cultivars were different. Light interception was more important for early cultivars. Less foliage inclination angle would be benefit to intercept more solar energy during yielding period; but for late soybean cultivars, the colony was more closure and LAI was higher, so big foliage inclination angle in all layers of high yielding colony made more solar radiation penetrate into the inner canopy, which would be good for yield formation
    PLANT PROTECTION
    Molecular Genetics of Pathogenicity Determinants of Xanthomonas oryzae pv. oryzae
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    Scientia Agricultura Sinica. 2004, 37(09):  1301-1307 . 
    Abstract ( 959 )   PDF (734KB) ( 1094 )   Save
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    Xanthomonas oryzae pv. oryzae (Xoo) is the causal agent of bacterial blight disease in rice. The Xoo-Rice interaction is consistent with the "gene-for-gene" hypothesis and is an ideal model system for understanding mechanisms of molecular plant-pathogen interactions. In the last decade, important pathogenicity-related genes of Xoo had been cloned and identified. Genomic bioinformatics of other gram-negative plant bacterial pathogens, including other Xanthomonas species, has facilitated research on molecular pathogenicity determinants of Xoo, especially on mining TTSS (type III secretion system) effectors. A brief review on the current knowledge of the molecular mechanisms of Xoo pathogenicity is made in order to provide a basis for functional genomics of molecular rice-Xoo interactions.
    The Relationship Between Resistance to Controlled Atmosphere and Insecticides of Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae)
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    Scientia Agricultura Sinica. 2004, 37(09):  1308-1315 . 
    Abstract ( 820 )   PDF (780KB) ( 603 )   Save
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    A systematic study was conducted on the important stored product insect, Liposcelis bostrychophila Badonnel, which is about the cross-resistance of 4 resistant strains, HCO2-R (hypercarbia-resistant strain), HCLO-R (hypoxia and hypercarbia resistant strain), DDVP-R(DDVP-resistant strain) and PH3-R (PH3- resistant strain). The results indicated that there were cross-resistances between CA and insecticides, and the quantities of the cross-resistances were different. The cross-resistance factor (RF) of HCO2-R to hypoxia and hypercarbia was 3.2458, while, that of HCLO-R to hypercarbia was 1.8280. The RF of DDVP-R to PH3 was 3.9614, while, that of PH3-R to DDVP was 2.7852. The RF values of DDVP-R and PH3-R to hypercarbia were 1.3550 and 1.1816, respectively. However, the RF of HCO2-R to DDVP was 2.1372. There was also a low cross-resistance between DDVP-R and HCO2-R. The RF of HCO2-R to PH 3 was 3.3698. This suggested that the insects resistant to high CO2 concentration atmosphere would develop significant resistance to PH3, however, the insects resistant to PH3 remain sensitive to hypercarbia atmosphere. Both DDVP-R and PH3-R developed resistance to high CO2 treatment. There was a low cross-resistance between DDVP-R and HCLO-R. The insects resistant to hypoxia and hypercarbia were very sensitive to DDVP. There was also a cross-resistance between HCLO-R and PH3-R, but the resistance of PH3-R to hypoxia and hypercarbia was lower than that of HCLO-R to PH3. The differences of the overlapping and separate values indicated that there were differences in the intercross-resistance of 4 resistance strains.
    Inhibitory Effects of Kojic Acid on Phenoloxidase of Diamondback Moth Plutella xylostella
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    Scientia Agricultura Sinica. 2004, 37(09):  1316-1321 . 
    Abstract ( 899 )   PDF (548KB) ( 1005 )   Save
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    The effects of Kojic acid on phenoloxidase (PO) of Plutella xylostella were studied, when which had been partially purified by 40% saturated [(NH4)2SO4] and Sephadex G-100 gel filtration. Kojic acid showed inhibitory effets on both monophenolase and o-diphenolase activity of the PO. The inhibitor concentrations leading to 50% (I50) activity lost were estimated to be 0.07 mmol?L-1 for monophenolase activity and 1 mmol?L-1 for diphenolase, respectively. Kojic acid can also prolong the lag time of PO for oxidation of L-tyrosine. The inhibitory kinetics were analyzed by Lineweaver-Burk plots and kojic acid was found to be a reversible competitive inhibitor with the Ki of 0.47 mmol?L-1. The ability of kojic acid to inhibit the enzyme activity may be associated with its ability to chelate copper at the active site. In addition, the iron ion was found to shorten the lag time obviously, but have no important effect on the monophenolase activity.
    SOIL & FERTILIZER·WATER-SAVING IRRIGATION
    Citrate on Mobilization of Fe and P in Calcareous Soil and Its Impact on Growth of Drip-irrigated Tomato
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    Scientia Agricultura Sinica. 2004, 37(09):  1322-1327 . 
    Abstract ( 1208 )   PDF (292KB) ( 755 )   Save
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    Differences in soil pH and DTPA extractable Fe and available P content near to emitter soil and bulk soil were investigated in the open-field experiment with drip and furrow irrigation. Results showed that drip irrigation improved marketable yield of cherry tomato with higher use efficiency of water and fertilizer. Soil available P, water content and pH value are higher in wet part soil of drip irrigation than that in non-wet part and in furrow irrigation plot. However, soil available Fe concentration decreased in drip irrigation. Adding citrate decreased soil pH, improved available Fe content in soil and increased Fe and P uptake by cherry tomato.
    Effects of Nitrogen Fertilizer on Zoysiagrass (Zoysia japonica Steud.) Seed Yields and Yield Components from Seeding and Transplanting
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    Scientia Agricultura Sinica. 2004, 37(09):  1328-1333 . 
    Abstract ( 1329 )   PDF (559KB) ( 797 )   Save
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    A study was conducted to determine the optimum N-fertilizer application rate for maximum seed yields of zoysiagrass stands from seeding and transplanting respectively, in Jiaozhou City, Shandong Province, from 2001 to 2003. The results indicated that in the third year after establishment, seed yields and yield components for both stands showed a similar response to N-fertilizer. Maximum fertile tiller numbers (3 342 and 2 941 heads·m·2 from stands seeded in rows and transplanted, respectively) and highest seed yields (844.50 and 874.65 kg·ha-1 from stands seeded in rows and transplanted, respectively) were reached at a fertilizer application rate of 20 and 10 kg N·ha-1 in autumn and spring (30 kg N·ha-1 in total). Further increase in N fertilizer application rate decreased the fertile tiller numbers and seed yields. The length of spikelet, spikelets per fertile tiller, seed numbers per head, seed setting percentage and 1000-seed weight increased with the application rate of N fertilizer. Compared with the stand seeded in rows, the 1000-seed weight and the length of spike from transplanted stand were higher. The optimal harvest time of Zoysiagrass in Jiaozhou City was about 36 days after anthesis, near June 15th, when the seed moisture content reached 26% -28%.
    Effect of Different Textural Soils on Root Dynamic Growth in Corn
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    Scientia Agricultura Sinica. 2004, 37(09):  1334-1340 . 
    Abstract ( 1331 )   PDF (519KB) ( 666 )   Save
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    Corn was planted in containers with a volume of 3 m × 2 m × 1 m , in which different textural soils including light loam, loam and light clay were filled as the natural status. The effect of soil textural on corn root was studied. The results showed that the morphology, distribution, growth of corn root system were significantly different among three kinds textural soils. Corn root in light clay changed direction frequently during growth process so that it had more curved root system compared with that in light loam and loam, which characterized by "more deeper in light clay soil, more finer root diameter". More sub-roots in basal and less sub-roots in deeper soil were also observed in light loam than that in loam and light clay soil. The sequence of average root diameter(ARD) was light clay>loam>light loam. At jointing stage, the vertical and horizontal distribution of corn root cultivated in light loam was the most extensive, followed by loam and light clay. However, no significant difference was found among three kinds textural soils after male tetrad stage. The portion of root in top soil increased with more physical light clay component in soil. Growth dynamic of corn root in light loam was characterized by "earlier development and earlier senescence". Daily increase rate of root length density in light loam was far higher than that in loam and light clay, which reached 538.6 m·m-3·d-1 before jointing stage and root amount reached maximum at silking stage, then root began senescent. Growth dynamic of corn root in light clay was characterized by "later development and later senescence", that daily increase rate of root was low in early stage, root amount reached maximum at doughy stage and senesce rate was far lower than that of light loam during late stage. Root in loam had a balanced growth during the whole period.
    Phosphorus Distribution in Two Wheat Cultivars as Affected by P Deficiency at Jointing and Flagging Stage
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    Scientia Agricultura Sinica. 2004, 37(09):  1341-1346 . 
    Abstract ( 843 )   PDF (542KB) ( 634 )   Save
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    P distribution and use efficiency in two wheat cultivars, e.g. large-spike cultivar CA9325 and multi-spike cultivar JM2, as affected by P omitting started at jointing and flagging stage were investigated under the controlled conditions, in order to obtain and provide scientific basis for the respective regulatory techniques and get higher yields according to the genetic characters of different wheat cultivars. The results showed that with the prolonged plant growth, the increase of P contents in main shoot, valid tillers and whole plants grown under P-sufficient conditions shown a typical "S" pattern, the peak of the P contents appeared at grain filling stage. In all of the treated plants, P percentage in main shoot to whole plant of both cultivars showed a steady increase. However, it decreased gradually in the invalid tillers and roots, and also in the valid tillers of P-deficient plants in both cultivars; The P content and percentage of P in grains of main shoot in the P-sufficient CA9325 were higher than those in valid tillers; but it was contrary in JM2, because they belonged to different spike types of wheat. P contents in all vegetative organs and glumes in the P-deficient plants were lower than those in the P-sufficient plants. As a result, the percentage of P in grains of main shoot and valid tillers of the P-deficient plants were higher than those of the control plants; At harvest, the grain yields of the P-deficient plants of both cultivars were lower than those of the control plants. In comparison, P uptake efficiency of the P-sufficient CA9325 and P harvest indexes of all treated CA9325 plants were higher than those in JM2. However, P use efficiency of CA9325 was lower than that of JM2. The differences in P use efficiency in plants between the two cultivars were discussed.
    HORTICULTURE
    Study on Distribution of Nitrogen, Phosphorus and Potassium of Tomato in Different Crops in Solar Greenhouse
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    Scientia Agricultura Sinica. 2004, 37(09):  1347-1351 . 
    Abstract ( 1052 )   PDF (461KB) ( 761 )   Save
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    The experiment was conducted in solar greenhouse using Zhongza9 tomato variety in order to investigate the light and temperature in greenhouse, and the distribution of nitrogen, phosphorus and potassium in soil culture in winter-spring and autumn-winter crops. The results showed that the distribution of total N, P2O5 and K2O was influenced by light and temperature condition in greenhouse. Both in winter-spring and autumn-winter crops, the distribution trend of total N, P2O5 and K2O was the same as dry material, i.e. before fruit formation stage, mainly distributed in the stem and leaves, in fruit formation stage, mainly distributed in the fruit. In autumn-winter crop, because of the abominable light and temperature condition, the distributing proportion of N, P2O5 and K2O in early stage of picking and middle stage of picking was higher than that in winter-spring crop. The concrete proportion changed with different elements and growth stages.
    Analysis of Chromosome Meiotic Behavior of F1 Hybrids and Its Backcross Generations Between Ogura-Type Male-SterileBrassica napus L. and B. campestris L.
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    Scientia Agricultura Sinica. 2004, 37(09):  1352-1357 . 
    Abstract ( 926 )   PDF (208KB) ( 488 )   Save
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    F1 between female parent of Ogura male sterility Brassica napus L. (AACC,2n=38) and male parents of B. campestris ssp. chinensis, B. campestris ssp. rapifera (AA, 2n=20) was made, and BC1 and BC2 generations were produced. The number of somatic and gametic chromosomes of F1 hybrid were 29 and 19, respectively. In the strong growth plant of BC1, the chromosome configuration of Xinxuan1 and Naibing98-1was 10Ⅱ+9Ⅰ,the chromosome configuration of Aijiaohuang were mostly 10Ⅱ and 10Ⅱ+7Ⅰ. In the weak growth plant of BC1, the chromosome configuration of Xinxuan1 and Naibing98-1was 10Ⅱ+7Ⅰ, the chromosome configuration of Aijiaohuang was mostly 10Ⅱ+1Ⅰ. In the strong growth plant of BC2, the chromosome configurations of Xinxuan1 and Aijiaohuang were 10Ⅱ+1Ⅰand 10Ⅱ, respectively, the chromosome configuration of Aijiaohuang was mostly 10Ⅱ. In the weak growth plant of BC2, the chromosome configuration of Xinxuan1 and Aijiaohuang was 10Ⅱ, the chromosome configurations of Naibing98-1 were mostly 10Ⅱ+6Ⅰand 10Ⅱ+5. The chromosome number in Aijiaohuang and Xinxuan1 was 20. The percentage of cell with 2n=20 was 78.12%. Irregular segregation of chromosomes was observed of the BC1 plants during meiosis. These results suggested that the homologous of chromosomes between AACC and AA genome, and it is easy to obtain the CMS in B. compestris by several generations of backcross.
    Isolation of Pollen Protoplasts in Solanum tuberosum
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    Scientia Agricultura Sinica. 2004, 37(09):  1358-1362 . 
    Abstract ( 1185 )   PDF (423KB) ( 571 )   Save
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    Mature pollen protoplasts of Solanum tuberosum were isolated by means of "cold pretreatment- germination-enzy- matic treatment". The buds were first incubated at 6℃, then mature pollens were germinated. When most of the pollens grains had just produced short pollen tubes, they were transferred to an enzymatic solution. The process of pollen protoplasts isolation was as follows: firstly, plasm membrance seperated from the cell wall, then the protoplasts inside pollen wall were partially extruded through the germinal hole after the action of enzyme solution, and finally the spherical protoplasts were detached from the exine of pollens. Pollen protoplasts yield was greatly influenced by the germination duration time and mannitol concentrations in enzymatic solution, and 30 min germination and 1 mol·L-1 mannitol were optimal. The enzymatic solution consists of 1% cellulase (R-10), 0.5% hemicellulase (Sigma), 1% pectinlase (Serva), 0.5% potassium dextran sulfate, 1% PVP, 0.01% CH and K3 medium. The highest pollen protoplasts yield was 19.40%. Wall degraded pollens were identified with 0.1% calcoflower white test and its vitality was tested by fluorochromatic reaction with fluorescein diacetate (FDA).
    Preliminary Identification of Red Carotenoids from Potamogeton crispus L.
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    Scientia Agricultura Sinica. 2004, 37(09):  1363-1368 . 
    Abstract ( 905 )   PDF (425KB) ( 518 )   Save
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    Three red pigments r1, r2 and r3 were extracted and separated from Potamogeton crispus L, the UV-Vis spectra, FT-IR spectra, test by chemical reaction and Mass spectra were studied. The visible spectra of r1, r2 and r3 in acetone, methanol, ethanol, chloroform and carbon disulphide had only a single, rounded, almost symmetrical absorption peak, the shape of visible spectra was similar to that of canthaxanthin and astaxanthin. but the visible spectra of them in hexane had a asymmetrical absorption peak that were approximate to the "three-peaked spectra"; but the visible spectra of β-carotene(non-oxocarotenoids) was typical "three-peak spectra". As compared with the spectra in hexane, the λmax of r1, r2 and r3 increased along with the strengthening in solvents polarity, and the shape, fine structure and λmax of their spectra were greatly affected by the solvents. The average λmax of r1, r2 and r3 in the six solvents were larger than that of astaxanthin, canthaxanthin and β-carotene, respectively. The FT-IR spectra of r1, r2 and r3 showed the characteristic frequencies of polyene chain compounds containing carbonyl groups (there were differences in 1 660-1 750 cm-1 ). The test by chemical reaction showed that r1, r2 and r3 were carotenoids containing carbonyl groups ( not 5, 6 or 5, 8-Epoxides). It is an important evidence to prove that r1, r2 and r3 are carotenoids containing carbonyl groups and having molecular formula C40H50O2 , molecular weight 562 determined by low and high resolution EI-MS. They have no identical structure with canthaxanthin, astaxanthin and β-carotene. The results show that r1, r2 and r3 are the isomers of rhodoxanthin.
    ANIMAL SCIENCE·VETERINARY SCIENCERE·SOURCE INSECT
    Homogenous Identification of a Group of Polymorphic High Molecular Weight Protein in Sow Milk
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    Scientia Agricultura Sinica. 2004, 37(09):  1369- . 
    Abstract ( 1177 )   PDF (300KB) ( 533 )   Save
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    High molecular weight proteins (HMWP) in sow milk showed four variants of A, B, C, and D by SDS-PAGE. HMWP-B was purified by a combination of ammonium precipitation, SephadexG-200 gel filtration chromatography and High Q column anion-exchange chromatography. The rabbit anti- HMWP-B Polyclonal Antibody was then raised. Immunoblotting of HMWP in sow milk showed immunological cross reaction among these variants and indicated HMWP in sow milk are homologous. The result of this study provides a proof for the hypothesis of polymorphism of HMWP .
    Analysis of Rumen Bacterial Diversity of Goat by Denaturing Gradient Gel Electrophoresis and 16S rDNA Sequencing
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    Scientia Agricultura Sinica. 2004, 37(09):  1374-1378 . 
    Abstract ( 892 )   PDF (431KB) ( 889 )   Save
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    Diversity of rumen bacteria of the rumen content of Chinese white goats was analyzed by PCR amplification, denaturing gradient gel electrophoresis (DGGE) and sequencing of 16S rDNA clone libraries. DNA was extracted from rumen contents of goats fed two diets with and without the addition of daidzein. The V6-V8 region of 16S rDNA of bacteria was amplified and the amplicons were then separated based on a linear gradient of denaturants in DGGE, a fingerprinting technique. A clone library was created from complete 16S rDNA. From the library, 16 clones had their V6-V8 regions matched predominant bands on the DGGE gel and their 16S rDNAs were then sequenced and subjected to an online similarity search. Five clones showed their similarities with database sequences over 97%, with one sequence similar to Prevotella sp., the rest were similar to those unidentified rumen bacteria. From the library, eight clones with similarities in the range of 90%~96% and the remaining three clones were less than 90%.
    Immunity Effects Mechanism Treated with Elemene-Combo Tumor Vaccine
    Scientia Agricultura Sinica. 2004, 37(09):  1379- . 
    Abstract ( 978 )   PDF (261KB) ( 407 )   Save
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    The possible relationship between heat shock protein (HSP) and the molecular mechanisms of active immunization of elemene-combo tumor cell vaccine (TCV) was tudied by using murine H22 ascitic hepatic carcinoma and L615 leukemia as the experimental models. Stressors, such as elemene or/and heat shock, were applied to study the following items: treated with different concentrations of elemene and different time course of heat shock, transmission electron microscopy were used to observe the morphological influence on tumor cells. Direct immunofluorescent flow cytometry (FCM) was used to detect the apoptotic rate of H22 and L615 tumor cells and influence on the expression of membrane HSP70 and HSP90. The membrane HSP70-peptide complex was separated and purified from H22 and L615 tumor cells induced by different stressors (elemene, MMC) and then a preliminary in vivo active immunoprophylaxis experiment was carried out using those isolated HSP70-peptide complex against H22 on Balb/c mice and L615 on 615 mice. Under transmission electron microscope, the influence of elemene or heat shock on the two kinds of tumor cells is, to some extent, the same or almost the same, which means the apoptosis and necrosis of the cells. The extent of the influence on the two kinds of tumor cells is different, and L615 leukemia was more sensitive and undergoing bigger morphological changes than H22 hepatic carcinoma. It's further proved by FCM that both elemene and heat shock alone can induce the apoptosis of mice H22 hepatic carcinoma or L615 leukemia cells, with the intensifying of this effect by combining use of the two, the apoptosis of cells from mice L615 leukemia relates closely to the concentration of elemene and the time course of heat shock at 42℃. By separating and purifying Balb/c and 615 mice immunized by HSP70-peptide compound of H22 and L615 tumor cell induced by elemene or MMC, the results showed that all mice survived within one month, while none of the mice in control immunized by buffer D survived.
    Study on Detection of Resistance in Veterinary Pathogen by Using Oligonucleotide Array
    Scientia Agricultura Sinica. 2004, 37(09):  1385-1389 . 
    Abstract ( 1369 )   PDF (429KB) ( 484 )   Save
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    Detection of the antimicrobial resistance in common veterinary pathogen by using oligonucleotide array was studied. A pair of primers was designed to amplify fragments of gyrA gene from E. coli, S. aureus and M. gallisepticum, and simultaneously label fluorescence with cy5-dCTP. A series of oligonucleotide probes with which to detect the resistance to fluoroquinolones in the above three bacterial apecies were designed, then dotted and immobilized onto the oligonucleotide array by APS-PDC method. The labelled PCR products were hybridized with the oligonucleotide array, and the signals were scanned and analyzed with a ImaGene 3.0 software. The results showed that the hybridized oligonucleotide array presented detectable signals, and were consistent with the facts. This study demonstrated that the array could distinguish single base mutation between wild types and mutant types of E. coli,S. aureus,M. gallisepticum, and was able to identify differences in the wild strains and mutant strains occurring at positions 83 and 87 of the GyrA subunit. The preliminary results demonstrated that oligonucleotide array provided an accurate, sensitive and feasible tool for the detection of resistance in veterinary bacteria. The present study may provide a basis for further research and development of gene chip in monitoring resistance to antimicrobial agents.
    RESEARCH NOTES
    Combining Crop Modeling and QTL Mapping into an Integral Plant Breeding Strategy
    Scientia Agricultura Sinica. 2004, 37(09):  1390-1395 . 
    Abstract ( 1416 )   PDF (577KB) ( 814 )   Save
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    Crop models have now been increasingly used to assist plant breeding to define crop ideotypes for different environments. In genetics, the advent of molecular markers enables the dissection of a complex trait into a number of quantitative trait loci (QTL), and assists the transfer of these QTL into desired cultivars or lines. A recent study has shown that QTL information can successfully be coupled to crop models to replace measured parameters. QTL-based modeling has overcomed the limitations in ideotyping of using models that ignore the inheritance of model-input traits. On the other hand, crop modeling can potentially be a powerful tool to resolve the interactions between genotype and environment and overcomes the limitation that QTL mapping cannot extend an experimental result of one environment to another environment condition. An approach that integrates marker-assisted selection into model-based ideotyping framework to support breeding for high crop yield was discussed.
    Rapid Identification of Carbendazim Resistant Strains of Sclerotinia sclerotiorum Using Allele-Specific Oligonucleotide (ASO)-PCR
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    Scientia Agricultura Sinica. 2004, 37(09):  1396-1339 . 
    Abstract ( 1126 )   PDF (312KB) ( 550 )   Save
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    Benzimidazole fungicides are important mixture components to control rape sclerotinia rot disease in China. Carbendazim-resistant isolates of Sclerotinia sclerotiorum have been detected in fields since 1996. In this paper, three pairs of degenerate primers were used to amplify theβ-tubulin gene from S.sclerotiorum. The gene from S.sclerotiorum has 1 685 bp, including 4 introns, encoding 447 amino acid. Except for the difference in the number of the introns, the deduced amino acid sequence of the β-tubulin gene from S.sclerotiorum are 95.78% to 97.66% identical to those of other six plant pathogenic filamentous fungi. Resistance was related to a point mutation in codon 198 where the glutamic acid has changed into alanine, which caused the occurrence of resistance field. A DNA fragment surrounding codon 198 was amplified directly from genomic DNA of sclerotinia using two pairs of Allele-Specific Oligonucleotide(ASO) primers to detect resistant frequency accurately. Using this method within 6 h, the detection rate for benzimidazole resistance was up to 100%; in comparison with the conventional assay procedure, which needs 1-2 weeks, the accuracy of the new method was 96%.
    Responses of the Microbial Biomass P to the Changes of Organic C and P in Paddy Soils
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    Scientia Agricultura Sinica. 2004, 37(09):  1400-1406 . 
    Abstract ( 925 )   PDF (599KB) ( 946 )   Save
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    Responses of microbial biomass P (MB-P) to organic C and P in paddy soils with various fertilization practices (inorganic and organic fertilizers) were investigated using 5 long-term field trials in Hunan, China. Results indicated that the amount of soil MB-P and their responses to the applications of different fertilizers differed with soil types. Changes in soil MB-P was insensitive to inorganic fertilizers (NPK) applied in most of the trials. However, the amount of soil MB-P generally increased by application of organic manure and incorporation of rice straw. The relation between MB-P and total P or total organic carbon was indeterminate, although the content of MB-P, to some extent, could respond to the changes of total P or total organic carbon. Meanwhile, the MB-P was more closely related to NaHCO3 extractable P (Olsen-P) or MB-C than to total P or total organic carbon. MB-P amounted to 1.16%-3.19% of total P in the paddy soils, which was similar to the percentage of Olsen-P to total P. When the content of extractable P was less than 8 mg·kg-1, the content of MB-P was more than extractable P no matter where in fertilization or in non-fertilization plots, suggesting that a high content of microbial biomass P could regulate extractable P in paddy soil. The positive correlations between the amount of MB-P and various fractions of inorganic P except O-P indicated it was a possible key that the conversion of Fe-P, Al-P and Ca-P into extractable P was accomplished by soil microorganisms in paddy soils.