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Table of Content

    10 March 2007, Volume 40 Issue 3
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES
    Progress and Prospect of Functional Rice Researches
    Scientia Agricultura Sinica. 2007, 40(3):  433-439 . 
    Abstract ( 1590 )   PDF (308KB) ( 1808 )   Save
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    With the quick development of economy and the level of people’ living condition, functional foods have become gradually embraced by consumers and have a great growth potential. Rice is the main staple food in China, it plays an important role in people’s health promotion and public nutrition improvement, and here is an ever-increasing consumer demand for the functional quality of rice. This review introduces the concept of functional rice and summarizes the current research progress on this topic and the application of breeding strategies including traditional breeding, induced mutation, molecular marker assisted selection and transgenic engineering in the research of a new generation of functional rice that posses health benefits,therapeutic values, bioreactor properties, and other unique functions. In the last, we point out the prospect of the functional rice from the social development, germplasm innovation, the breeding of functional rice by biological technology and the test of active material related functional rice. We conclude that developing and marketing of functional rice is becoming a hot research focus in the near future.
    Review on Low-molecular-weight Glutenin Subunits and Their Coding Genes
    Scientia Agricultura Sinica. 2007, 40(3):  440-446 . 
    Abstract ( 1441 )   PDF (398KB) ( 1207 )   Save
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    The Low-molecular-weight glutenin subunits (LMW-GS) of wheat is about 1/3 of seed storage proteins and 60% of gluten fraction, and have great effects on dough extensibility and food processing quality, thus became one of the main factors for wheat quality improvement. However, resolution of the LMW-GS and the scoring of their alleles by direct analysis of proteins are more difficult due to the larger number of expressed subunits and their overlapping mobility with the abundant gliadin proteins. In this paper, the nomenclature and structure features of LMW-GS, their coding gene loci on chromosomes and allelic variation, the registered genes in Genbank and classification, and their relations with quality were reviewed. We also discussed the identification of LMW-GS genes and their development of molecular markers based on the author’s own research results, in order to provide a theoretical basis for using LMW-GS in breeding quality wheat cultivar and marker assistant selection.
    Detection of the QTLs Controlling Important Traits and Analysis of Their Stability in Different Cropping Seasons in Rice Using SSSLs
    Scientia Agricultura Sinica. 2007, 40(3):  447-456 . 
    Abstract ( 1695 )   PDF (425KB) ( 1369 )   Save
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    【Objective】QTL detection using Single segment substitution lines(SSSLs)overcame the limitations of conventional mapping populations and were utilized easily in breeding. Single segment substitution lineswith only single chromosome segment from a donor under the same genetic background as the recipient each were developed by advanced backcrossing and molecular marker-assisted selection. 【Method】Detection of the QTLs controlling 23 important traits in rice was done with 32 SSSLs by the randomized blocks design. 【Result】Fifty-nine QTLs were detected and distributed on chromosomes 1,2,3,4,6,7,8,10,11, of which 18 QTLs were detected two times or more. Only 30.5% of the QTLs were detected repeatly in different cropping seasons . Most QTLs of agronomic importance were of little effects and unstable. The QTLs controlling the traits such as grain weight, grain length, ratio of grain length to width and heading date were relatively stable. The stable QTLs usually had larger additive effects and less affected by environment. The unstability of QTLs of agronomy importance may be the genetic basis for improving yield and quality in rice by culture methods.
    Cloning and molecular characterization of LMW glutenin subunit genes in Triticum dicoccoides
    Scientia Agricultura Sinica. 2007, 40(3):  457-463 . 
    Abstract ( 1431 )   PDF (624KB) ( 928 )   Save
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    Study the Effects of High Molecular Weight Glutenin Subunits (HMW-GS) On Quality traits using the population of recombinant inbred lines-5(RIL-5)
    Scientia Agricultura Sinica. 2007, 40(3):  464-471 . 
    Abstract ( 1600 )   PDF (235KB) ( 985 )   Save
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    The effects of HMW subunits on quality traits were analyzed quantitatively. The results showed that the effects were different significantly among different subunits at the same loci for dough development time,dough stability time, breakdown time,Mixing time, Zeleny sedimentation value, gluten index,area, extensibility, maximum resistance, 8 minute curve tall, peak value ,bread volume,bread score and bread firmness . On the contrary,no significant differences were detected for dry gluten content,protein content and hardness. The influences of 8 different subunit combinations at different loci of RIL-5 were different significantly for physics and chemistry characteristic , dough rheology characteristic and bread making quality, but there were not significant different for protein content.This to say, different subunits at the same loci and different subunit combinations at different loci have significant effect on wheat quality traits.
    TILLAGE & CULTIVATION·PHYSIOLOGY & ECOLOGY
    The Studies on the Genetic Difference of Nitrogen Utilization Efficiency in Winter Wheat Varieties
    Scientia Agricultura Sinica. 2007, 40(3):  472-477 . 
    Abstract ( 1682 )   PDF (209KB) ( 1255 )   Save
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    In order to study the genetic difference of nitrogen contents of grain, leaf and stem and nitrogen utilization efficiency(NUE) among wheat varieties,the randomized blocks experiments were made for 29 wheat varieties in the normal and the fertilizer and water deficiency environments,respectively. The results showed that the difference of nitrogen contents of grain, leaf and stem and nitrogen utilization efficiency among varieties were highly significant; the difference of nitrogen contents of leaf and stem and nitrogen utilization efficiency among environments were highly significant; the difference of nitrogen contents of grain among environments were not significant; variety×environment interaction of nitrogen contents of leaf were highly significant; nitrogen utilization efficiency of all varieties was higher in the fertilizer and water deficiency condition than normal environment condition; 5 and 4 varieties that nitrogen utilization efficiency were higher were selected in the normal and the fertilizer and water deficiency environment conditions. Correlation of nitrogen contents of grain and leaf and nitrogen utilization efficiency was highly significant under two environment conditions. The plot heritability ratio of nitrogen contents of grain, leaf and stem and nitrogen utilization efficiency were 48.4%, 7.6%, 17.4% and 35.4%; and their variety heritability ratio were 84.9%, 89.1%, 55.8% and 76.7%. It is thus clear that genetic improving nitrogen utilization efficiency of varieties and breeding high-production,good-quality and high-efficiency utilization nitrogen new wheat varieties are possible.
    Effects of rhizobial inoculation and light shading on nitrogen fixation and photosynthetic physiology of soybean
    Scientia Agricultura Sinica. 2007, 40(3):  478-484 . 
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    【OBJECTIVE】The interactive effects of light strength and nitrogen supply on soybean growth and photosynthetic physiology were studied. 【METHOD】Plant growth, photosynthetic gas exchange and chlorophyll fluorescence in soybean ( Glycine max (L.) cv. Heinong 37 ) were investigated after inoculated with Sinorhizobium fredii USDA191 under light-shaded and subsequent light-recovered conditions.【RESULTS】The results showed that, under non-shaded condition, plant biomass, chlorophyll contents and photosynthetic capacity were significantly increased in soybean following rhizobial inoculation as compared to those of the control plants; while under light-shaded condition, the photosynthetic rate of the rhizobia-inoculated soybean was markedly decreased compared to the non-inoculated control plants due to the influences of stomatal conductance and non-stomatal factors, showing that the inoculated rhizobia did not play the role in nitrogen fixation. Under light-recovered condition, the photosynthetic parameters were not recovered to the degree as that of the non-inoculated control plants. 【CONCLUSION】It is concluded that the positive effects of symbiotic nitrogen fixation can be attained only under suitable light condition.
    Physiological reaction differences of rapeseed (Brassica napus L.) with different waterlogging-tolerance to anoxia
    Xue-kun ZHANG
    Scientia Agricultura Sinica. 2007, 40(3):  485-491 . 
    Abstract ( 1573 )   PDF (408KB) ( 1061 )   Save
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    The seedlings and germinating seeds of rapeseed (B. napus L.) with different waterlogging tolerance (WT) were used to analysis the physiological reaction in anoxic stress. After 12h anoxic stress to germinated seeds, the waterlogging tolerant genotype was different significantly than susceptive genotype with higher relative root and shoot length, fresh weight, survivor rate and relative vigor index, but lower electrical conductance. Without anoxic stress, the three seedling leaves of WT genotype had lower soluble sugar and similar lever in soluble, proline and malnodialdehyde (MDA) content than susceptive genotype. After 48h anoxic stress to three leaves seedling, the WT genotype showed significant different physiological reactions compared to the susceptive genotype with the rapid increase of soluble sugar and proline contents, lower relative electrical conductivity and MDA content. The different physiological reaction also occured in activities changes of activated oxygen scavenger enzyme, activities of the peroxidase (POD) and superoxide dismutase (SOD) of WT genotype increased rapidly but catalase (CAT) decreased after anoxic stress, where susceptive genotype with similar SOD, increase in CAT but decrease in POD.
    Effect of phloridzin on physiology of M hupehensis seedlings
    Jianghong Zhang
    Scientia Agricultura Sinica. 2007, 40(3):  492-498 . 
    Abstract ( 1526 )   PDF (876KB) ( 1196 )   Save
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    Abstract: M hupehensis seedlings growing in sand were treated with 0.001, 0.1, 1, 10 mmol L-1 of Phloridzin every fourth day for three times. Effect on plant morphology and physiology characteristic was investigated. The results showed that phloridzin improved seedlings growth at 0.001mmol L-1 and inhibited the growth of seedlings at 1mmol L-1.Inhibition rate of phloridzin on seedlings enhanced with higher concentration. At 1mmol L-1 , deformation of the ultrastructures of chloroplast,mitochondrion in leaf and root was observed accompanying with increased MDA content and SOD activity. Activities of POD and CAT increased firstly, then decreased, and then increased again. Photosynthesis rate and respiratory rate of M hupehensis seedlings were reduced at higher concentration of phloridzin.
    PLANT PROTECTION
    Genetic Analysis of Gene Conferring Resistance to Stripe Rust in Xiaoyan6
    Scientia Agricultura Sinica. 2007, 40(3):  499-504 . 
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    Abstract: Xiaoyan6 is a famous variety that has durability to stripe rust, developed by using exogenous genes from Elytrigia elongata at the end of 70’s last century .To confirm the resistant genes under normal temperature(16±1℃) it was crossed with susceptible cultivar MingXian169 and set dialed crossed among them. It suggests that there is one dominant gene controlled when tested with either race CY28 or CY29-mut3 in xiaoyan6. The chromosomes location of the gene was determined by the materials of monosomic Chinese Spring, the result showed the resistant gene was located on chromosome 4B. 11 SSR markers was used to identify , the resistant gene was located on chromosome 4BL. The genetic distance of xgwm107 to YrXY was 7.08 cM by mapmaker.
    Population genetics of Phytophthora infestans:Ⅰ—Virulence Genes and Virulence Structure of P.infestans on Potato in Yunnan During 2000 to 2003
    Scientia Agricultura Sinica. 2007, 40(3):  505-511 . 
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    The knowledge of virulence and variation of pathogen caused of plant disease is very important to breed resistant varieties and distribute resistance genes. Virulence genes and virulence structure of isolates of Phytophthora infestans collected from twenty nine potato production regions under different ecological types in Yunnan during 2000 to 2003 were determined systematically by a whole set of potato differentials. The results showed that all eleven known virulence genes with different frequency from 2.9~97.8% that could overcome all resistance genes were detected in these isolates. Among the virulence genes, the occurrence frequency of vir1、vir3、vir4、vir7、vir9、vir10 and vir11 were all above 86% and that of vir5 and vir8 were below 5%. All of 136 isolates showed complex virulence structure, among which 28 different virulence types were detected, and 4-11 virulence genes with an average of 7.3 were existent in each virulence type. The virulence types of 1.3.4.7.9.10.11, 1.2.3.4.6.7.9.10.11, 1.3.4.6.7.9.10.11 and 3.4.6.9.10.11 were prevalent ones during 2000 to 2003. High diversity of virulence of P.infestans were revealed in North-east and north-west planting zones and Middle multiple cropping zones. The supervirulence structure 1.2.3.4.5.6.7.8.9.10.11 was detected firstly in Yunnan. All known resistance genes were susceptible in Yunnan and new resistance resources or breeding strategy need be deployed.
    Several culture properties of the pathogenic microorganism causing tobacco blank shank
    Scientia Agricultura Sinica. 2007, 40(3):  512-517 . 
    Abstract ( 1458 )   PDF (633KB) ( 1038 )   Save
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    Total sixty-nine Phytophthora nicotianae Breda de Haan var. nicotianae Waterhouse isolates were obtained from diseased tobacco stem tissue collected from 10 different localities in Anhui, which Bozhou, Guoyang, Xuxian, Taihe, Lixin, Guzhen, Fengyang, Hefei, Shexian and Wuhu. The main culture character of theses sixty-nine isolates were studied via sporangia abduction, partnership culture in vitro, growth properties mensuration, et al, results showed that these Phytophthora nicotianae Breda de Haan var. nicotianae Waterhouse were heterothallic, with amphigynous antheridia and small oogonia, able to produce oosopora when partnership culture with standard mating type isolates in vitro, and that sporangia were mostly spherical or approximatively spherical, with short caduceus and conspicuously papillate (single or double), easily falling off, and attached some diverse length mycelia-like silk. The asymmetry shape sporangia appeared frequently. The optimum temperature for mycelial growth in vitro was between 20℃ to 30℃, the maximum beyond 35℃ and below 40℃, and the minimum beyond 8℃ and below 10℃.
    Production and Identification of High Affinity Monoclonal Antibodies against Pesticide Carbofuran
    Scientia Agricultura Sinica. 2007, 40(3):  518-523 . 
    Abstract ( 1406 )   PDF (410KB) ( 1183 )   Save
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    To prepare hapten BFNB of carbofuran,Balb/c mice were immunized by synthesized BFNB-BSA. The splenocytes of immunized mice were fused with Sp2/0 cells and the cultural supernatants of hybridoma cell were screened by indirect ELISA with BFNB-OVA as coated antigen. Purified McAbs was got from ascites fluids deposited by octanoic acid and ammonia sulfate. The specificity and affinity of McAbs were characterized by ELISA.A hybridoma cell line (5D3) secreting anti-carbofuran McAb had been established. The titre of culture medium and ascites were up to 1∶2.048×103 and 1∶1.024×106 respectively. The immunoglobulin class of the McAb was IgG1. McAbs showed a high affinity (Ka5D3=2.54×109L/mol, IC50=1.9 ng/mL) and minimum cross reactivity for several analogous compounds of carbofuran (7×10-4% for carbofuranphenol, others less than 10-4%).The specific monoclonal antibody against carbofuran was obtained successfully and this made it possible to establish ELISA for rapid detection of carbofuran.
    SOIL & FERTILIZER·WATER-SAVING IRRIGATION
    Dynamics of Soil Microbial Biomass Nitrogen and Fixed Ammonium in reddish clayey soil during Pot Experiment
    Scientia Agricultura Sinica. 2007, 40(3):  524-531 . 
    Abstract ( 1404 )   PDF (320KB) ( 769 )   Save
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    【Objective】It was studied the immobilization of nitrogen by microbe and crystal cell in reddish clayey soil after amending urea and straw as well as the dynamics of soil microbial biomass nitrogen (SMBN) and fixed ammonium during the period of rice growth. 【Method】 A flooded pot experiment was conducted during the period of rice growth and composed of four treatments which were control group (CK), labeled urea group (15NU), the combined application of labeled urea and rice straw powder group (15NU-S) and the combined application of labeled rice straw power and urea group (15NS-U). 【Result】 During the period of rice growth, the percentage of SMBN and fixed ammonium to total nitrogen were 1.90% ~ 5.91% and 4.77% ~ 8.37%, respectively; SMBN was minimum at rice booting stage and fixed ammonium was minimum at rice tillering stage; For SMBN, there was no significant difference between fertilizers treatments at rice matured stage and the same to fixed ammonium. The immobilization of urea nitrogen by microbe and crystal cell were 4.01 ~ 15.14 mg·kg-1 and 0.47 ~ 4.82 mg·kg-1, respectively; and the percentage of labeled substrate SMBN and labeled substrate fixed ammonium to urea nitrogen were 1.76% ~ 8.83% and 0.28% ~ 2.11%, respectively. The immobilization of rice straw nitrogen by microbe and crystal cell were 0.97 ~ 2.85 mg·kg-1 and 0.09 ~ 0.50 mg·kg-1, respectively; and the percentage of labeled substrate SMBN and labeled substrate fixed ammonium to rice straw nitrogen were 1.69% ~ 4.98% and 0.15% ~ 0.87%, respectively. The combined application of urea and rice straw powder groups (CAURS, including 15NU-S and 15NS-U) increased the assimilation of microbe, decreased the immobilization of crystal cell. There was a significant negative relationship between SMBN and fixed ammonium. The maximum releasing rate of SMBN in 15NU and CAURS were 66.04% and 69.15%, respectively; those of fixed ammonium in 15NU and CAURS were 87.75% and 87.64%, respectively.【Conclusion】During the period of rice growth, the immobilization of labeled substrate nitrogen by microbe and crystal cell was a dynamic process. SMBN and fixed ammonium reached the minimum at the booting stage and the tillering stage, respectively. The CAURS increased the assimilation of chemical fertilizer by microbe and decreased the immobilization of chemical fertilizer by crystal cell.
    Response of maize to progressive drought and drought threshold of red soil
    Scientia Agricultura Sinica. 2007, 40(3):  532-539 . 
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    【Objective】Study the response of maize (Zea may L.) to progressive drought and soil drought degree formulation and the threshold of red soil.【Method】Summer maize was planted in field plot with rainproof shed, and six treatments were disposed in which soil drying form 12 days to 36 days. The soil water contents in 0-60cm layers were measured daily with FDR, and maize plant morphic features and leaf stomatal conductance are also investigated periodically. We checked seed and measured grain yield after harvest.【Result】The plant height, stem diameter, leaf stomatal conductance and root number decreased significantly after different soil drought days, namely, the threshold response presented to special soil drought conditions. Five percent grain yield reduced significantly after soil drought lasted 25 days. In soil drying development, the relationship between the soil layer water storage and the cumulative relative water loss was expressed as a logarithmic linear equation. We transferred the slope to an index, notated as D, which spans in the interval [0, 1], to explain the soil drought degree.【Conclusion】The index D is an indicator both for soil drought degree and crop water stress. Maize yield decrease significantly when red soil drought degree D reached 0.55 in the elongation-heading stage.
    The equilibrium and growth stability of winter wheat
    Scientia Agricultura Sinica. 2007, 40(3):  540-548 . 
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    The competing and reciprocal relation model of winter wheat root and shoot is described. The root and shoot equilibrium and growth stability is studied on the basis of kinetics system theory. Result assumes that root and shoot, as the whole functional structure of crop, having been pursuing mutual equilibrium in their life, but they can not come to a equilibrium state forever, they are always in a disequilibrium state from beginning to end of their life, this is the essence of root and shoot equilibrium. In thia paper, it is suggested that neither the root nor the shoot can develop no limit, they are all controlled by the growth behavior of crop. Water stress inhibit the function of root and shoot, minish the mutual influence of root and shoot, as a result, make the crop growth gradually tend to stebility. The stably growth time of crop become longer with water stress aggravating. Rewatering augment the mutual influence of root and shoot, promote the rate of dry matter acumulation(DMAR), prolong time of instable growth, as a result, crop show a extra-compensatory effect. Rewatering during flowering stage can upset the inherent relativity long time stable growth during flowering stage, lead to growth unstably, promote DMAR.
    Distributions of water, salinity, and nitrogen in cotton root zone by different fertigation strategies
    Scientia Agricultura Sinica. 2007, 40(3):  549-557 . 
    Abstract ( 1389 )   PDF (654KB) ( 1438 )   Save
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    【Objective】It is of great importance to study the distributions of water, sanility and nitrogen in soil and cotton root for optimizing soil salinity, irrigation and fertilization strategies with drip irrigation. 【Method】Spatial distributions of water, salinity and nitrogen in cotton root zone were investigated in a pot experiment with different irrigation and fertilization methods under greenhouse conditions. According to the application order of nitrogen (N) fertilizer solution and water (W) involved in an irrigation cycle, four fertigation treatments were designed, nitrogen applied 1) in the beginning of the irrigation cycle (N-W), 2) at the end (W-N), 3) in the middle (W-N-W), and 4) throughout the irrigation cycle (NW). Conventional nitrogen fertilizer broadcasted in soil following surface irrigation was the control (SN-W). 【Result】Distributions of water and salinity in soil were significantly influenced by irrigation methods, but no differences were found between the four nitrogen fertigation strategies. 15N in the soil profile was concentrated at depth 0-20 cm 24 h after fertigation, and the distribution of %15N atoms in soil was significantly influenced by the different fertigation strategies. In strategy NW, 15N in the soil moved deeper and there was less lateral movement 24 h after fertigation than in the other treatments, and significant amounts of residual soil nitrate were found in deeper soil layers after harvest. In contrast, nitrogen was more evenly distributed at 0-20 cm depth 24 h after a fertigation cycle and fewer nitrates were left at the end of experiment after N-W treatment, and furthermore, the distribution of roots with N-W treatment was also better. 【Conclusion】These results suggest that the N-W strategy would work better in increasing nutrient-use efficiency, and reducing the risk of chemical leaching from the root zone.
    HORTICULTURE
    The Influence of Co-suppressing Tomato 1-Aminocyclopropane-1-Carboxylic Acid Oxidase I on the Fruit Ripening and Pathogenesis-Related Proteins
    Scientia Agricultura Sinica. 2007, 40(3):  558-565 . 
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    Abstract: 【Objective】The purpose of this study is to explore the influence of co-suppressing tomato ACC oxidase I on the fruit ripening and pathogenesis-related proteins and on the biosynthesis of endogenous ethylene and storage ability of fruits. 【Method】Several gene specific fragments of tomato(Lycopersicon esculentum) were cloned, such as the 1-aminocyclopropane-1-carboxylic acid oxidase I gene(LeACO1), 1-aminocyclopropane-1-carboxylic acid oxidase III gene(LeACO3), EIN3-binding F-box 1 gene(LeEBF1), pathogenesis-related protein 1 gene(LePR1), pathogenesis-related protein 5 gene(LePR5) and pathogenesis-related protein osmotin precursor gene(LeNP24) by PCR or RT-PCR. Then these specific DNA fragments were used as probes to hybridize with the total RNAs extracted from the wild type tomato(WT) and the LeACO1 co-suppression tomatoes(V1187 and T4B),respectively. In the same time, ethylene release measurement and storage experiment of tomato fruits were carried out.【Result】The hybridization results indicated that the expression of fruit ripening-related genes ,such as LeACO3 and LeEBF1, and pathogenesis-related protein genes, such as LePR1,LePR5 and LeNP24, were reduced sharply, and the amount of ethylene release in whole independent leaves, wounded independent leaves and whole fruits decreased and the storage time of ripening fruits was prolonged, when the expression of LeACO1 gene in tomato was suppressed.【Conclusion】In the co-suppression tomatoes, the expression of fruit ripening-related genes and pathogenesis-related protein genes were restrained at the different degrees, the biosynthesis of endogenous ethylene decreased and the storage ability of tomato fruits increased.
    Molecular Weight Distribution of Rice Starches and Its Correlation with Viscosity
    Scientia Agricultura Sinica. 2007, 40(3):  566-572 . 
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    The molecular weight distribution rule and intrinsic viscosity on rice starches were measured by gel permeation chromatography and Ostwald viscometer, respectively. The relationship between molecular weight distribution and intrinsic viscosity of rice starches was studied. Rice starch has 3 main fractions, amylose, intermediate and amylopectin. Relative molecular weight of rice amylopectins is about 89.58×106g/mol~1 559.76×106g/mol, while rice amyloses is about 4.06×106g/mol~6.85×106g/mol. The molecular weight distribution of rice amylopectin is narrower than rice amylose. The molecular weight distribution of intermediate is wider. The intrinsic viscosity of rice starches is about 77.65g/g~237.53g/g. When molecular weight and molar ratio of amylopectin are bigger, intrinsic viscosity is higher. But amylose with bigger molecular weight and higher molar ratio may make intrinsic viscosity to be lower. The relationship between rice molecular weight distribution and intrinsic viscosities of rice starches could be described accurately by an exponential model.
    Study on Browning Mechanism of Pomegranate Peel during Storage and Technology of Preventing Pomegranate Brown
    Scientia Agricultura Sinica. 2007, 40(3):  573-581 . 
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    【Objective】Peel browning is the key problem during pomegranate storage. The browning mechanism of pomegranate peel during storage and the technology of preventing pomegranate brown were studied in the paper. 【Method】The effects of storage temperature, gas component and pH on peel browning of Shaanxi Lintong sweet pomegranate were researched, and the changing rule of tannin that the main substance causing peel browning was investigated. The relationship between the activities of ascorbic acid oxidase (AAO), polypenoloxidase (PPO), peroxidase (POD), catalase (CAT) and peel browning were analysed. 【Result】Tannin was the basal substance of pomegranate peel browning. The activities of AAO, PPO and POD were correlated with the browning index of peel. On the contrary, there was a negative correlation between the activity of CAT and the browning index. Pomegranate fruit stored under the conditions of pH 4.0, 5.0±0.5℃ and 5.0%CO2+8.0%O2+87.0%N2 gas component were treated with intermittent warming of 24 h at 15±0.5℃ every 5 days, the browning index was 0.15 after 120 days of storage. 【Conclusion】Enzymatic tannin denaturation was the main reason that led to peel browning during storage. The effect of preventing peel brown was optimal by intermittent warming storage with suitable pH, temperature and gas component.
    ANIMAL SCIENCE·VETERINARY SCIENCERE·SOURCE INSECT
    Preimplantational development of porcine embryos derived from in vitro fertilization, parthenogenetic activation and somatic cell nuclear transfer
    Scientia Agricultura Sinica. 2007, 40(3):  588-593 . 
    Abstract ( 1304 )   PDF (315KB) ( 1904 )   Save
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    The present study were designed to examine the developmental competence of preimplantational embryos derived from in vitro fertilization, parthenogenetic activation and somatic cell nuclear transfer in pig, and to evaluate the quality of porcine blastocysts derived from IVF, PA and SCNT. In addition, the effects of porcine zygote medium 3 (PZM-3) and North Carolina State Medium 23 (NCSU-23) on the developmental potential on the porcine PA embryos (PAEs) and SCNT (NTEs) embryos was also investigated. The results are as follows: ① for the cleavage rate, no significant difference was observed among IVF embryos (IVFEs), PAEs and NTEs (72.0%,66.0% and 63.5%, p>0.05), meanwhile for the blastocyst formation rate, no significant difference was obtained neither (11.0%,22.6% and 16.9%, p>0.05). However, for the quality of blastocysts, i.e. the ratio of inner cell mass (ICM) to total cell number, the IVFEs and NTEs were both superior to PAEs(0.448%, 0.356% vs. 0.122%, p<0.05). ② as for PAEs, the blastocyst rate was significantly higher when cultured in PZM-3 than cultured in NCSU-23(35.4% vs. 22.6%, p<0.05); while as for NTEs, similar results of PZM-3 and NCSU-3 in supporting blastocyst formation were observed (26.6% vs. 21.1%, p>0.05), although the cleavage rate was obviously higher in PZM-3 group than NCSU-23 group(47.5% vs. 63.5%, p<0.05). In conclusion, ①the poorest quality of blastcysts was generally observed in PAEs; ② the ideal culture medium for PAEs may not be necessarily beneficial to NTEs.
    Effect of IGF-1 on expression of related hair follicle growth factors and receptors in varied sheepskin
    Scientia Agricultura Sinica. 2007, 40(3):  594-600 . 
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    Thirty-six healthy and similar Xin jiang sheep were selected and divided into six groups at random. Each animal was plucked and shaved at pro-scapulae region and injected intradermally with 0.5 mL IGF-1 (10ng/mL) at the cross section of plucking, shaving and control, except sheep, as control of no injection IGF-1, sampled for 0 day. When sampled, the treatment sheep were selected one out of five groups at random, and sampled plucked tissues, shaved tissues and control, respectively for 3,6,9,12 and 50 days. The expression of encoding growth hormone receptor (GHR), insulin-like growth factor1 (IGF-1), insulin-like growth factor receptor (IGF-1R), KAP3.2 and KAP6-1 mRNA were measured in each sample, with relative quantitative reverse transcription polymerase chain reaction (RT-PCR) using beta-actin as an internal standard. The results indicate that, 1). In normal sheepskin, the expression of GHR in injected IGF-1 decreased, no evidently changes of IGF-1 and IGF-1R, and that of KAP3.2 and KAP6-1 increased markedly.2). In plucked sheepskin, the abundance of GHR mRNA in injected IGF-1 reduced in short term (3 day), but no clearly changes in long term (above 6 day); meanwhile, compared with control, there were no changes of expression of IGF-1 and IGF-1R. The pattern of expression changes of KAP3.2 and KAP6-1 were similar, which were promoted significantly in both, but the expression of KAP3.2 prior to that of KAP6-1.3). In shaved sheepskin, the levels of GHR and IGF-1 mRNA were increased dramatically after injection IGF-1, but there has no clear fluctuation of IGF-1R; likely, the pattern of expression changes of KAP3.2 and KAP6-1 were similar, which were promoted significantly in both, but the expression of KAP3.2 prior to that of KAP6-1, too.
    Research on cloning and expression of VPg1-2, VPg2-3, VPg3 gene fragments of foot-and-mouth disease virus and antibody dynamics of expressed VPg1-2 protein
    Scientia Agricultura Sinica. 2007, 40(3):  601-607 . 
    Abstract ( 1737 )   PDF (523KB) ( 936 )   Save
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    Abstract VPg1-2, VPg2-3, VPg3 gene fragments were successfully subcloned from 3ABC gene of the foot-and-mouth disease virus ( FMDV ) Taibao strain and their expressing plasmids were constructed by inserting the target gene fragments into pGEX-4T-1 vector. The expressed proteins were analysed by Western blotting. The results showed that the expressed VPg1-2, VPg2-3 proteins reacted with FMDV positive serum while the reaction of the VPg3 protein was negative. An indirect ELISA was set up using purified VPg1-2 protein as antigen, and 4 groups of background-known cattle sera were tested. Negative results were obtained for the non-vaccinated control group and the vaccinated group and a part of the infected post-vaccination group(3/7). On the contrary, positive results were achieved for the infected group and a part of the infected post-vaccination group(4/7). In the infected group and infected post-vaccination group, the longest duration of the antibody against VPg1-2 lasted for at least 90 days. The earliest appearing time of VPg1-2 antibody was10 days after infection.
    Protection of Polysaccharide Nucleic Acid Fraction Bacillus Guerin to Mammary Tissue of Goat Experimental Mastitis Induced by Endotoxin
    Scientia Agricultura Sinica. 2007, 40(3):  608-613 . 
    Abstract ( 1227 )   PDF (499KB) ( 996 )   Save
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    Abstract: 【OBJECTIVE】For further study on therapeutic method of Mastitis, it was in the paper that protection of polysaccharide nucleic acid fraction Bacillus Guerin to mammary tissue of goat experimental Mastitis induced by Endotoxin.【METHOD】Six healthy Suining white goats at early stages of lactation were intramammary infused with polysaccharide nucleic acid fraction of Bacillus Calmette Guerin (BCG-PSN) (5mL) in the left quarters and physiological saline (5mL) in the control contralateral quarters. The administration of BCG-PSN was carried out for six consecutive days. On the seventh day, the mammary quarters (both right and left) of the six goats were infused with Escherichia coli endotoxin (LPS) (50μg/bwt). At varying intervals of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 24h before and after infusion inflammation was recorded. After 24h, the animals were slaughtered and mammary tissue was collected from the same position. A section was fixed for histopathological evaluations and the remaining tissue was stored at -70℃.【RESULTS】Clinical and histopathological examinations indicated that infusion of endotoxins induced acute mastitis in both quarters. The results showed that infusion of BCG-PSN significantly reduced activity of N-acetyl-β-D-glucosaminidase (NAGase), Myeloperoxidase (MPO), alkaline phosphatase (AKP), nitric oxide synthase (iNOS) and the concentration of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (P<0.05). There was a general reduction in the levels of mRNA cytokine expression (P<0.05). These findings suggest that BCG-PSN inhibits release of inflammatory factors that cause damage to mammary epithelial cells during mastitis infections in goats.
    SPECIAL TOPICS
    Developing the agro-grassland system to insure food security of China
    Scientia Agricultura Sinica. 2007, 40(3):  614-621 . 
    Abstract ( 1490 )   PDF (348KB) ( 1174 )   Save
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    In China, the concern over food has been given first priority. The concept of food has been narrowed to something equivalent to grain or foodstuff due to the traditional idea that "food was the heavenly principle to people". The ideas of "foodstuff would be shared by human beings and livestock" and "foodstuff-pig agriculture" caused a big dilemma to the stratagem of safegarding China's food security. The concept of Food Equivalent Unit is introduced and the midium and long term goals in development of Chinese food system based on the 2 +5 model was proposed. The model would be not only able to yield enough grain production for people to consume but also able to produce the amount of fodder twice over the grain. Advantages of the agro-rassland system should be fully taken in order to develop the produtive potentials of the Farmland Equivalent Unit in China thereby to solve the problems of Chinese food security fundamentally.
    An Empirical Study on Agricultural Support of Agricultural Policy in China
    Scientia Agricultura Sinica. 2007, 40(3):  622-627 . 
    Abstract ( 1596 )   PDF (317KB) ( 1157 )   Save
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    This paper makes an empirical analysis on the agricultural support in China for the period of 1994-2003 by using the OECD methodology. The research findings demonstrate that the general support level to agriculture shows an upward tendency; the policies such as the increase of investment on rural infrastructure make the general services support estimate increased; market support policy and the reform of tax and fee make the producer support estimate change from negative to positive. Nevertheless, the support level in China is still very low compared to some developed countries, the Chinese government should further substantially increase the support to agriculture.
    RESEARCH NOTES
    The analysis of the spikelet structure and heredity of germplasm resource in multiple grain sorghum
    Scientia Agricultura Sinica. 2007, 40(3):  628-632 . 
    Abstract ( 1668 )   PDF (243KB) ( 957 )   Save
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    In this paper, The anatomized observation of the spikelet structure of the cultivated multiple grain sorghum variety SZ0 and the sorghum double grain varieties which were collected from home and broad was carried on, and found that there exits the exceptional structure of the third glume, double awn, multi-lodicule, multi-seed, multi-pistil , multi-anther, multi-stigma, and twinborn conjoined seeds in the spikelet of the multiple grain sorghum. Multiple grain properties was controlled by the homologous gene and the composite grain properties gene of different varieties behaves differently. In the variety of TX431, It is dominance to single grain to multiple one. In our farmhouse variety of our country, It is recessiveness to single grain to multiple one.
    Effects of Propamidine on Mycelium Shape and Ultrastructure Changes of Botrytis cirerea
    Scientia Agricultura Sinica. 2007, 40(3):  633-637 . 
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    The mycelium ultrastructure changes of Botrytis cirerea treated with propamidine was studied through light microscopy (LM) and transmission electro microscopy (TEM). Treated with propamidine one day, by LM, the space between mycelium septum was shortened, the part of mycelium was swelled; After three days, the swelled part of mycelium was malformation. Through TEM, the volume of mycelium cell mitochondrion was swollen , its number increased after treated with propamidine one day; Then treated three days, the configuration of mycelium cell was destroyed. Above cytological changes result in the necrosis of hyphal cell.
    The Hyperspectral Characteristics and Retrieval of Soil Organic Matter Content
    Scientia Agricultura Sinica. 2007, 40(3):  638-643 . 
    Abstract ( 1781 )   PDF (383KB) ( 1115 )   Save
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    The study aims to search for the hyperspectral bands most sensitive to soil organic matter content and the retrieval model. In the field, the spectra of soils samples were measured by an ASD PRO FR2500 in the 350~2500nm regions.Then the hyperspectral reflectance data were transformed to several Organic matter Identification Index (OII). According to the result of the correlation analysis, the 511nm region was regarded as the best detecting band for soil organic matter content. Moreover, the accuracy of retrieval model is the highest using the OII as the independent variable in the linear model.
    Construction of Chimonanthus Praecox Flower cDNA Library and Expression Analysis of High-abundancy cDNA of Lipid Transfer Protein (LTP)
    Scientia Agricultura Sinica. 2007, 40(3):  644-648 . 
    Abstract ( 1338 )   PDF (450KB) ( 1203 )   Save
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    【OBJECTIVE】To construct the cDNA library of Chimonanthus Praecox flower and analyze the expression of LTP cDNA ; 【METHOD】The cDNA library was constructed from flowers of Chimonanthus Praecox , using the SMART cDNA Library Construction Kit. The expression of LTP cDNA was analysed through reverse transcription polymerase chain reaction (RT-PCR);【RESULTS】The primary library has a high titer of 1.4×106 pfu/ml, in which 98% clones are recombinant and the insert cDNAs are more than 0.5 kb, with an average of 1.1 kb. The amplified library has a titer of 1010pfu/ml. The positive signals of PI, AP3 and LTP gene were detected by PCR in the amplified library, though they were expressed at different abundances. The LTP gene from the amplified library has no intron, which showed no genomic DNA in the library. RT-PCR showed LTP gene had high transcript levels during the different blooming stages, which is consistent with the fact that it was expressed at high abundance in the mini EST library;【CONCLUSION】This high quality cDNA library can be further used for gene clone and ESTs analysis and provides a useful tool for the study of the molecular mechanisms of winter-blooming of Chimonanthus Praecox.