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Table of Content

    10 December 2007, Volume 40 Issue 12
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES
    Advisement of application of gene transformation in rice breeding
    Fu Ya-Ping 付亚萍 Liu-Wenzhen Liu Hu-Guocheng Hu Si-Huamin Si Sun Zong-xiu Sun
    Scientia Agricultura Sinica. 2007, 40(12):  2659-2666 . 
    Abstract ( 1520 )   PDF (369KB) ( 1999 )   Save
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    During the period 1996 to 2006, the global area of GM crops has increased consistently every year. In 2006, it reached 102 million hectares. Trustfully, transgenic rice will eventually be commercialized, therefore, it is time to make theoretical, technical and material provision. The viewpoints of the authors are the following: The technology roadmap should adequately exert advantages of transformation and integrate other biotechnologies based on the conventional breeding, which is critical to make excellent results. It is important to excelsior select target gene(s), construct efficient and safety vectors, optimize transformation system, improve transformation frequency of indica rice and reduce somaclonal variation during transformation. To ensure enough lines is necessary for selection in the field and 200 lines is recommended. The best time for monitor potential transgenic lines is the regional yield trails. Some principles should be followed during study on rice bioreactor and phytoremediation. Lastly, frequent communion and close cooperation among scientists in different area is helpful to market the GM rice.
    COMPARISON of GENETIC DIVERSITY LEVEL BETWEEN EUROPEAN and EAST-ASIAN WHEAT COLLECTIONS by SSR MARKERS
    Scientia Agricultura Sinica. 2007, 40(12):  2667-2678 . 
    Abstract ( 1520 )   PDF (590KB) ( 1563 )   Save
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    Bread wheat (Triticum aestivum L.) is a major cereal crop for both human and animal food. This species is originating from the Fertile Crescent in the Middle-East. At the Neolithic period, initial germplasm was widespread by the first farmers in both Europe and East-Asia. Therefore, wheat diversity evolved under different environmental conditions and selection pressures in each continent. Today, the comparison of genetic diversity level between these two contrasted wheat germplasms may be a useful way, for both geneticists and breeders, to find new sources of variation. In this paper, 371 European and 363 Asian collections were genotyped by 38 genomic SSR and 44 EST-SSR markers. Total 865 alleles were detected, with range from 1 to 50 and a mean of 10.42. Polymorphism information content (PIC) ranged from 0 to 0.91 with an average of 0.53. Genetic diversity level in East-Asia was higher than that in Europe. European and Asian accessions were divided into two distinct sub-groups by PCO based on 83 SSR loci. The position of materials in the dendrogram was accordant with their geographical location, i.e. accessions from near geographical location were jointing into neighbours. Allele differentiation between the two continents at some loci such as Xgwm186, Xgwm257, Gpwm7433 and Gpwm7443 was very significant. This may be corresponding to the natural and breeding selection, which was supported by the marker/trait association analysis results. Chinese varieties released from 1950 to 1980 were clustered into one big group with Europeans, and far away from native landraces and varieties released before 1950. This is consistent with wheat breeding history of China. Diversity revealed by genomic SSRs was much higher than that by EST-SSRs. However, the cluster trend based on the two types of SSR was consistent. Therefore, differentiation of repetitive DNA was much rapider than functional genes in breeding selection. European germplasms can be efficiently used in Chinese wheat breeding program through backcross breeding method.
    Proteomic Study of Anther of Cytoplasmic-Nuclear Male-Sterile Line NJCMS1A in Soybean
    Scientia Agricultura Sinica. 2007, 40(12):  2679-2687 . 
    Abstract ( 1203 )   PDF (717KB) ( 1374 )   Save
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    【Objective】 The present paper was aimed at the comparative proteomic study of anther at binucleate pollen stage between NJCMS1A and its maintainer NJCMS1B in soybean. 【Method】 Two-dimensional gel electrophoresis (2-DE) technique was used to separate the protein spots and Coomassie Blue G-250 was applied to stain the gels. The PDQuest image software was applied to analyze the difference between the protein maps of anthers from NJCMS1A and NJCMS1B. Then the matrix-assisted laser-adsorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) technique was used to obtain the peptide mass fingerprinting of the differentially expressed proteins and the MASCOT software was used to search the protein database NCBInr to identify the spots interested. 【Result】 About 212 protein spots were detected within Mr18.4~116.0 kD and pH 4~7. Total 24 spots out of 212 were differentially expressed between NJCMS1A and NJCMS1B. Among these, 10 protein spots were present in the anther protein map of NJCMS1A but absent in that of NJCMS1B, and 12 protein spots present in that of NJCMS1B but absent in that of NJCMS1A, another two protein spots were up-regulated significantly in the map of NJCMS1B in comparison with that of NJCMS1A. The identified results were as follows: 10 proteins were present in NJCMS1A anther at binucleate pollen stage but absent in NJCMS1B. These were 1-aminocyclopropane-1 -carboxylate oxidase , AIG1-like protein, 20S proteasome beta 5 subunit, Oligouridylate binding protein, Cysteine proteinase, Cullin, Putative beta-amyrin synthase, Hypothetical protein MtrDRAFT_AC146570g8v1, Vacuolar H+-ATPase A subunit, Adenosine/AMP deaminase. Six proteins were absent in NJCMS1A anther but present in NJCMS1B. These were NBS-type resistance protein, putative NBS-LRR protein GS05, MADS box protein, Starch branching enzyme, ACC synthase 2, UDP-glucose pyrophosphorylase.【Conclusion】 According to the literature, the functions, especially those related to male sterility of the major differentially expressed proteins, including 1-aminocyclopropane-1-carboxylate oxidase (ACC oxidase), ACC synthase 2, cysteine proteinase, vacuolar H+-ATPase A subunit, MADS box protein, starch branching enzyme and UDP-glucose pyrophosphorylase were reviewed and discussed. It was inferred that the cytoplasmic-nuclear male-sterility of NJCMS1A might be related to energy metabolism turbulence, the programmed cell death (PCD), ethylene excessive synthesis, starch synthesis suffocation and the regulation of the flower developmental gene.
    Cloning and Sequence Analysis of Genes for Flavonoid Biosynthesis in Brassica juncea
    Scientia Agricultura Sinica. 2007, 40(12):  2688-2695 . 
    Abstract ( 1455 )   PDF (300KB) ( 1049 )   Save
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    【Objective】 The genes for flavonoid biosynthesis are to be cloned in Brassica juncea .【Method】Homology-based cloning strategy was used in this study. The primers were designed according to the sequences of homologous genes of the model plant Arabidopsis thaliana. The gene fragments were sequenced, and analyzed by BLAST.【Result】The 17 fragments were cloned and sequenced from 13 pairs of specific primers, which were confirmed to correspond to the Arabidopsis thaliana homologous genes and belong to the 13 known functional genes. The gene chs for chalcone synthase has 3 fragments different in size, while the genes pap for production of anthocyanin pigment and chi for chalcone isomerase have 2 fragments each. 【Conclusion】The homology- based cloning of the genes for flavonoid biosynthesis in Brassica juncea is viable. The cloned fragments of genes for flavonoid biosynthesis will provide the foundations for uncovering the genetic regulation of seed coat color formation in Brassica juncea.
    DNA fingerprint analysis of sesame mutantline by space mutagenesis
    Jian SUN
    Scientia Agricultura Sinica. 2007, 40(12):  2696-2701 . 
    Abstract ( 1340 )   PDF (349KB) ( 1145 )   Save
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    Abstract:【OBJECTIVE】To reveal differences of sesame space mutantlines in DNA level and discuss their molecular mechanisms which provide theory basis for crop space-flight mutation breeding.【METHOD】DNA fingerprint analysis was performed between three mutantlines and their original CK line “Yuzgi No.4” by amplified fragments length polymorphism (AFLP) technology for the first time.【RESULTS】Three mutantlines and their CK line were analysed by random selecting 30 pairs AFLP primers, 625 polymorphic bands were produced in 1176 DNA bands which were obtained in four samples, and its degree of gene polymorphism was 53.15%. DNA polymorphic bands were amplified between three mutantlines and their CK line during every primer pairs. UPGMA clustering showed that three mutantlines which were similar had biggish differences by comparing with “Yuzhi No.4”. 【CONCLUSSION】Space-flight mutagenesis could result in variation of sesame germ plasm, so space-flight mutantion breeding was an effective approach of plant breeding. AFLP was also a high efficient molecular biological method of researching plant space-flight mutagenesis.
    TILLAGE & CULTIVATION·PHYSIOLOGY & ECOLOGY
    Developing trend, basic principles and research orientation of conservation tillage
    Scientia Agricultura Sinica. 2007, 40(12):  2702-2708 . 
    Abstract ( 1375 )   PDF (242KB) ( 1348 )   Save
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    Based on the analysis of characteristic and development trends of conservation tillage in the world, the concept of conservation tillage (CT) was defined as an integrative technology system, which will reduce soil erosion and protect ecological environment in agricultural system. The key technologies of CT include the technology of minimum tillage and no-tillage, the technology of micro-topographical alteration and the technology of surface coverage. The principles of CT are to achieve “lower soil disturbances”, “less bareness”, “less pollution”, “moderate moisture”, “moderate roughness” and to maintain sustainable productivity of farmland. According to the concept and principles of CT, the research orientations and the key technologies suited for different regions in China of CT were put forward to build a China characteristic CT system.
    Spectral character of cotton single leaf infected with verticillium wilt and severity level of disease estimation
    Bin CHEN Ke-Ru WANG Fang-Yong WANG Hai-Zhen TAN Guo-Qing LIU Jiang-Lu CHENG
    Scientia Agricultura Sinica. 2007, 40(12):  2709-2715 . 
    Abstract ( 1211 )   PDF (428KB) ( 1438 )   Save
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    【Objective】In order to elucidated characteristics of spectrum of cotton leaf infected with verticillium wilt and estimated its severity level (SL)to provide theoretic foundation for further monitoring cotton verticillium wilt at large scale using airborne and airspace remote sensing. 【Method】 The spectrum reflectance of cotton single leaf infected with verticillium wilt was measured in cotton disease garden and cotton field in different growth phase, meanwhile, SL of single leaf infected with verticillium wilt was investigated. The methods of first derivative spectral were used estimate accurately disease of cotton with Verticillium wilt when compared with the reflectance spectrum of different single leaf infected of verticillium wilt. 【Result】The results indicated that Spectral characteristic of cotton leaf infected with verticillium wilt had better regularity with the increase of SL in different periods and varieties. Spectral reflectance increased significantly at visible light region (400~700nm) and near-infrared region (700~1300nm) with the increase of the SL ,and specially signification at blue- violet to red regions(525~680nm) when SL got 25%, cotton leaf of verticillium wilt could be used as a watershed and diagnosed index in early time. There were evident different characteristics of first derivative spectra in these disease leave, it changed significantly in red edge ranges(680~780nm) in different disease level, derivative spectra of red edge swing decreased, and red edge position equal moved to the blue. The thesis indicated that 434~724nm and 909~1600nm were selected out as sensitive bands region to SL of single leaf. Some inversion models for estimating cotton leaf diseased level of verticillium wilt all reached the best significantly level.【Conclusion】The results suggested that different characteristics of spectrum of cotton leaf infected with verticillium wilt were obvious. The model in which the first derivative spectra at 723nm could invert accurately the cotton leaf SL., and it may be used to forecasting the position of cotton leaf infected with verticillium wilt in quantitatively.
    Study on adaptation and introduction possiablity of winter rapeseed in dried and cold areas in Northwest China
    Scientia Agricultura Sinica. 2007, 40(12):  2716-2726 . 
    Abstract ( 1535 )   PDF (402KB) ( 1110 )   Save
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    Abstract:【Objective】The studies were conducted for studying on feasibility of expanding winter rapeseed northwards into dry,cold regions in Northwest China and screening of the winter type rapeseeds cultivars adaped to this area.【Method】Field experiments were carried out in 2001-2006 at 10 locations in northwest China’s Gansu Province where latitude ranged 35°30’-39°46’N, elevation ranged 1477-2300 m, precipitation ranged 92.0-630 mm, and annual average temperature ranged 5.9-8.7 oC.【Result】The 40 Brassica napus cultivars or breeding lines tested did not survive the local winter. All the 15 B. rapa materials tested, all of which were native of northwest China, had >70% overwintering rates at most locations. At Jiuquan, the northernmost location , only the ultra winter-hardy lines MXW-1 and DQW-1 survived the winter. The B. rapa winter rapeseed had desirable agronomic characteristics and outyielded spring rapeseed and flax. Its early maturity maximized the multiple crop index and increased unit land cash return. 【Conclusion】As a winter cover crop, it may eliminate a dust source that furnishes the damaging sand storms in northern China. It is not only possible but also beneficial economically, environmentally and ecologically to grow winter rapeseed in the dried and cold regions in northwest China.
    Low molecular weight organic acids in rhizosphere and their effects on cadmium accumulation in two cultivars of amaranth
    Scientia Agricultura Sinica. 2007, 40(12):  2727-2733 . 
    Abstract ( 1541 )   PDF (488KB) ( 1203 )   Save
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    【Objective】 To examine whether low- molecular weight organic acids (LMWOAs) in root exudates of amaranth play a role in Cd hyperaccumulation, we compared the amounts and composition of LMWOAs collected from two cultivars of amaranth,Zibeixian ,a low Cd accumulator,and Tianxingmi,a high Cd accumulator. 【Method】 Plants were grown hydroponically and three treatment (Cd 0、1 and 2.5 mg/L ) were later imposed for 1 wk before collection of LMWOAs. 【Result】 With the increase of solution Cd concentration, the biomass and its components of Zibeixian decreased dramatically, while those of Tianxingmi remained stable. In all treatment, total amount of LMWOAs in rhizosphere of Tianxingmi were significantly higher than that in Zibeixian,and the content of LMWOAs in two cultivars followed the same tendency, i.e. citric>malic>acetic>propinonic>butyric, and citric acid and malic acid predominated the composition of LMWOAs. The percent distribution of total LMWOAs of Zibeixian was very similar to Tianxingmi. With the increase of solution Cd supply, the content of LMWOAs in rhizosphere increased dramatically for both two cultivars, and the increment of LMWOAs of Tianxingmi was found to be greatly higher than that of Zibeixian. 【Conclusion】Therefore, Cd accumulation in amaranth was highly related to the total amount of LMWOAs in rhizosphere,and the differential increment of LMWOAs in the rhizosphere induced by Cd exposure may played an important role for Cd bioaccumulation by the high and low Cd accumulating cultivars of amaranth.
    PLANT PROTECTION
    Dynamic Development of Aphelenchoides besseyi on Rice Plant by Artificial Inoculations in Greenhouse
    Scientia Agricultura Sinica. 2007, 40(12):  2734-2740 . 
    Abstract ( 1468 )   PDF (324KB) ( 1404 )   Save
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    【OBJECTIVE】 In order to investigate the relationship between Aphelenchoides besseyi and the symptom of small grains and erect panicles, which was an important rice disease in jiangsu province. 【METHOD】Greenhouse experiments were designed by inoculating different numbers of Aphelenchoides besseyi on seedling bud and vagina of two Oryza sativa cultivars Zhendao No.2 and Wuyunjing No.7. The effect of small grains and erect panicles to rice growth was revealed through observing the disease development, seed expansion stages, the number of nematodes loaded in grains and nematode mortality caused by Aphelenchoides besseyi. 【RESULTS】The height, length and the numbers of spikelets of unhealthy panicles of Zhendao No.2 were decreased 6.7%, 16.4%, 13.5% respectively compared to healthy one. The distribution of nematode reproduction on rice was demonstrated that the percentage of infested seed and the number of nematode loaded were highest in normal expansion seeds with well developed endosperm, while lowest in empty seeds. The mortality of nematodes on grain was declined as the number of nematode loaded was rising, retaining lower level in plump seeds. 【CONCLUSION】Results indicated that Aphelenchoides besseyi was the pathogen of small grains and erect panicles. Wuyunjing No.7 just manifested small grains and erect panicles without the symptom of white-tip leaves. This phenomenon showed that the symptom of small grains and erect panicles was the new symptom of disease caused by Aphelenchoides besseyi on rice.
    Dot-blot hybridization for detection of five cucurbits viruses
    Scientia Agricultura Sinica. 2007, 40(12):  2741-2746 . 
    Abstract ( 1370 )   PDF (431KB) ( 1043 )   Save
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    Dot-blot hybridization was developed to detect 5 viruses infecting cucurbitaceous crops:Zuccini yellow mosaic virus(ZYMV),Watermelon mosaic virus(WMV), Cucumber mosaic virus(CMV),Papaya ringspot virus- watermelon strain(PRSV-W)and Squash mosaic virus(SqMV), and to provide a good alternative for detection of infected seeds in cucurbitaceous crops and for routine detection of 5 viruses in epidemiological and transgenic research.【Method】Using the clones of coat protein gene of five viruses, digoxigenin- labelled cDNA probes were synthesized by PCR with the specific primers designed according to the nucleotide sequences of the coat gene of the five viruses. The probes were applied in dot-blot hybridization to detect ZYMV、WMV、CMV、PRSV-W and SqMV in simple extraction of infected leaves.【Result】The sensitivity for detection of the simple extraction of infected leaves by ZYMV、WMV、CMV、PRSV-W and SqMV was 160、160、320、160、320 times respectively.【Conclusion】The digoxigenin-labelled probes prepared by PCR could be used for accurate and rapid identification of 5 viruses infecting cucurbitaceous crops in the growth stage with good stablities, sensitivities and specificness.
    Studies on the Mechanism of Epi-rotenone Enantiomorphs
    Scientia Agricultura Sinica. 2007, 40(12):  2747-2752 . 
    Abstract ( 1331 )   PDF (324KB) ( 1037 )   Save
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    【Objective】Study on mechanism of epi-rotenone enantiomorphs, (+)-5’β-epi-rotenone, (-)-5’α- epi-rotenone on insects. 【Method】The symptoms of Bombyx mori, treated with 5’β-epi-rotenone, 5’α- epi-rotenone were different, suggested that mechanism of epi-rotenone enantiomorphs maybe different from that of rotenone. The effects of epi-rotenone enantiomorphs on Na+,K+-ATPase , succinate dehydrogenase , AChE and bovine heart mitochondrial respiratory complex Ⅰwere measured. 【Results】The results indicated that epi-rotenone enantiomorphs had inhibiting effect on the Na+,K+-ATPase in the head of Bombyx mori, but it was found that only 5’α-epi-rotenone had activated effect on Na+,K+-ATPase in the midgut. Epi-rotenone enantiomorphs had activated effect on the activity of succinate dehydrogenase, the difference between 5’β-epi-rotenone and Blank were not significant, but that of 5’α-epi-rotenone and Blank were significant. Epi-rotenone enantiomorphs were no influence on the activity of AChE. Inhibiting effect on mitochondrial respiratory complex Ⅰ with IC50 value of 5’β-epi-rotenone, 5’α-epi-rotenone were 7.81mg/L、54.14mg/L, respectively. 【Conclusion】The differences of poison symptoms and inhibiting effect on enzymes indicated that mechanism of 5’β-epi-rotenone was the same with rotenone, but 5’α- epi-rotenone acted on Na+,K+-ATPase in the midgut and succinate dehydrogenase, besides on mitochondrial respiratory complex Ⅰ.
    Preparation of Chlorpyrifos Microcapsules and Its Controlled Realease Characteristics
    Scientia Agricultura Sinica. 2007, 40(12):  2753-2758 . 
    Abstract ( 1112 )   PDF (783KB) ( 1447 )   Save
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    【Objective】The controlled-release formulation of chlorpyrifos microcapsule encapsulated with UF-resin,and its controlled-realease kinetics were studied for optimizing the bioefficacy of chlorpyrifos.【Method】The effects of emulsifier, dispersant, and sodium chloride on encapsulation of microcapsule were investigated by biology photography microscope and photon correlation spectroscopy (PCS),and the controlled-realease characteristics were studied by gas chromatography.【Result】In the optimal foumulation, the mass weights of Styrene Maleic Anhydride(SMA)as emulsifier and Sodium Polyacrylate(PAAS)as dispersant were 2.5% and 2.0% respectively. And adding sodium chloride of mass weight of 0.4% could improve appearence of microcapsule. The mean diameter of microcapsules was about 10µm,and had good surface shape. The investigation of chlorpyrifos release behavior from microcapsules showed that in early 5 days it was coincided with First-level reaction,its equation was Ln(1- Q) =-0.0835t + 4.5102(R2 =0.9820).The release kinetics in 5-42days was coincided with Zero-level reaction,and followed the equation of Q = 1.6443t + 33.996(R2 =0.9927).【Conclusion】Chlorpyrifos microcapsules of UF-resin displayed good controlled-realease characteristics and satisfied the necessary prerequisites for prolonging control period.
    Monitoring of Alopecurus japonicus Steud. population resistant to haloxyfop-R-methyl in oilseed rape fields
    Scientia Agricultura Sinica. 2007, 40(12):  2759-2765 . 
    Abstract ( 1348 )   PDF (348KB) ( 1231 )   Save
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    【Objective】 The objective of this study was to investigate the resistance level of Alopecurus japonicus Steud. to haloxyfop-R-methyl, which is an ACCase inhibitor belonging to aryloxyphenoxypropionates (AOPPs), and its cross-resistance level to other herbicides with the same target site. A. japonicus seeds were collected from different oilseed rape fields where haloxyfop-R-methyl had been continuously applied for different years. 【Method】 The resistance level of A. japonicus to haloxyfop-R-methyl were evaluated by seed-bioassay and whole-plant test. 【Result】 The results showed that similar results were obtained by both of methods. In these two methods, the resistance factors of A. japonicus to haloxyfop-R-methyl, which were collected from Jurong in Jiangsu province, were 61.13 and 1331.68 respectively, which demonstrated the emergence of A. japonicus population resistant to haloxyfop-R-methyl in fields. The results of cross-resistance revealed that this resistant population of A. japonicus was also resistant to other AOPPs, in which the resistance level was: fluazifop-p-butyl>quizalofop-p-ethyl>fenoxaprop-p-ethyl. However, a relative low resistance level of this resistant population to sethoxydim was observed, which was a cyclohexanedione (CHD) herbicide sharing the same target with AOPPs. And the results obtained in laboratory were agreed with the real fact in fields.
    SOIL & FERTILIZER·WATER-SAVING IRRIGATION
    Enhancing spatial prediction of soil properties using elevation
    Scientia Agricultura Sinica. 2007, 40(12):  2766-2773 . 
    Abstract ( 1441 )   PDF (496KB) ( 810 )   Save
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    Abstract: 【Objective】This paper is concerned with increasing the accuracy of the spatial predictions of soil available nutrients (Cu, Fe, Mn, K, P and Zn), pH and soil organic matter (SOM) using elevation as ancillary variable. 【Method】The techniques applied were ordinary kriging (OK), cokriging (CK) and Simple kriging with varying local means (SKlm). The root of mean square error of prediction was used as the comparison criterion to assess the performance of each prediction method. 【Result】CK resulted in the most accurate estimates for K and pH, and SKlm for P, SOM and Zn, whereas both bivariate interpolation methods could not improve the accuracy of prediction for Cu, Fe and Mn relative to OK. 【Conclusion】The results suggest that the factors be responsible for prediction methods should be examined carefully before deciding on the most appropriate method of prediction
    Advances in nitrogen loss leached by precipitation from plant canopy
    Scientia Agricultura Sinica. 2007, 40(12):  2774-2779 . 
    Abstract ( 1400 )   PDF (307KB) ( 1092 )   Save
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    Function of canopy in changing nutrient cycle and flux is one of the focuses in recent years. On a basis of comprehensively appraising published research, we analyzed the nitrogen loss leaching from plant canopy and several factors which affected it. We pointed out the disadvantages of published research and the key problems that ought to be solved: (1) the mensuration need be advanced; (2) carrying out the research on nitrogen loss leaching from canopy of field plant; (3) carrying out the research on the type of nitrogen loss if the nitrogen is leached from plant canopy; (4) the nitrogen use efficiency of different variety should be contact with the research on nitrogen leaching; (5) carrying out the mechanism research on pathway and progress of nitrogen leaching, and the factors which affected it should be contact with the research, such as the leaf area of different growth stage, stomata density, stomata conductance and apparent free space, which is beneficial to explain the mechanism of nitrogen leaching from plant canopy.
    Effect of Potassium Chloride on Lignin Metabolism and Its Relation to Resistance of Corn to Stalk Rot
    Scientia Agricultura Sinica. 2007, 40(12):  2780-2787 . 
    Abstract ( 1475 )   PDF (426KB) ( 1312 )   Save
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    【Objective】This study was to elucidate the effect of potassium chloride (KCl) on lignin metabolism in corn, and discuss the physiological mechanism of KCl suppressing corn stalk rot. 【Method】A field experiment combined with plant analysis experiment was conduct to study the changes in lignin content and activities of phenylalanine ammonia-lyase (PAL), tyrosine ammonia-lyase (TAL), peroxidase (POD) and cinnamyl alcohol dehydrogenase (CAD) in stalk pith tissue of susceptible and resistant corn cultivars before and after inoculation by Fursarium graminearum, and the effect of KCl on the above noted changes. 【Result】The results showed that original content in resistant corn(Jidan180)was lower than that of susceptible corn(Jidan327), while the induced lignin content in resistant cultivar was more than that in susceptible cultivar. And KCl application decreased the original lignin content and increased the induced lignin content. The activities of PAL and TAL in stalk pith tissue were highest at 3 d after inoculation in the resistant cultivar, but increased slowly to a peak at 5 and 7 d after inoculation in the susceptible cultivar, respectively. KCl application decrease the background levels of PAL, TAL and POD activity, while increased the activities of PAL, TAL and POD(especially the maximum activity) in stalk pith tissue of the resistant and susceptible corns following pathogen invasion. In addition, KCl application enhanced CAD activity in the resistant and susceptible corns before and after inoculation. 【Conclusion】In conclusion, KCl stimulated the rapid expression of PAL, TAL, POD and CAD activities in both resistant and susceptible corns after inoculation, increased the induced lignin content, and then enhanced the resistance of corn to stalk rot.
    Succession and Enhancement Mechanism of Ecosystem Productivity after De-farming in the Ecotone between Agriculture and Animal Husbandry of North China
    Scientia Agricultura Sinica. 2007, 40(12):  2788-2795 . 
    Abstract ( 1077 )   PDF (283KB) ( 857 )   Save
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    Abstract: 【Objective】The succession and enhancement mechanism of the ecosystem productivity with the characteristics as de-farming in the ecotone between agriculture and animal husbandry of North China was discussed, in order to offer a way or technical basis for maintaining the permanent impetus of ecological recovery and economy development of the region. 【Method】Cases study in combining with theoretical analysis was adopted. 【Result】 In the regioin, after de-farming the biomass productivity of de-farming subsystem decreased by 38.4%~72.3% as compared with that of farming subsystem in the ecosystem, the main function of de-farming ecosystem should be focused on social resource-environment productivity, it caused the ideally beneficial recycling that was “de-farming-planting grass-raising animals-grain money” difficult to be realized. With the de-farming subsystem differentiation, the natural and social resources in the farming subsystem were accumulated, it laid basis for starting to upgrade the new characteristic of economic productivity. Case study showed that the system economic productivity was increased by 8.85~13.35 times due to re-coupling of the de-farming subsystem and farming subsystem, as well as coupling of crop production in the combined subsystems where existed the created microhabitat differentiation of water and fertilization that were the main concepts of the differentiation in the same field. 【Conclusion】 Structure rebuilding and opening operation of the de-farming ecosystem, playing the advantage of complementary co-operative production among different regions under conditions of the market economy, and rebuilding opening agricultural production structure were the important mechanism to enhance the system productivity in the ecotone between agronomy and animal husbandry of North China.
    Research on the Value of Soil and Fertilization Conservation in loess plateau in northern shaanxi pronvice
    Scientia Agricultura Sinica. 2007, 40(12):  2796-2803 . 
    Abstract ( 1555 )   PDF (486KB) ( 1068 )   Save
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    [Objective] Soil erosion is caused by mankind's survival increasingly scarce land resources degradation. To quantitatively calculate the value of the Soil and Fertilization Conservation,the paper provide the scientific decision-making for the sustained use of land for regional socio-economic development and ecological environment. [Method] Supported by “3S” technology , this paper brought for ththe landuse change in Loess Plateau in northern Shaanxi, from 1978 to 2000 , then studied the distribution rules of soil erosion under different landuse pattern quantificationally by Universal Soi Erosion Equation during that period, and emphasized the impact of changes of landuse patternon soil erosion. So, using market price, opportunity cost and alternative project, the value of vegetation’s soil conservation is calculated on its role in conserving soil fertility, reducing land abandon and reducing sediment accumulation.[Results] From the entire time, maintain the soil for the growth of 94.18%, nearly doubled from 1978 to 2000. The value of Soil and Fertilization Conservation in the Loess Plateau in northern Shaanxi province is 18.503 billion in1978;the value in 1990 an increase of nearly 800 million yuan than in 1978;the valure in 1990 is an increase of 241.4 million yuan than that is in 2000. [Conclusion] The value of the Soil and Fertilization Conservation in the loess plateau in northern shaanxi province trend from increasing to decreasing in 1978~2000 years, this feature is basically identical with the natural environment. If three different types of landscape areas, the results are : mountains in southern zone> sandstorm transitional zone in northern >Central loess hills area. But from 1978 to 2000 the average amount of soil map can see that The average amount significantly larger areas southward, it is mainly the weather conditions in recent years has had close relations.
    HORTICULTURE
    The photosynthetic heterosis and its underlying mechanisms of an inter-subspecific hybrid between Brassica campestris ssp. chinensis and B. campestris ssp. rapifera
    Jiashu CAO
    Scientia Agricultura Sinica. 2007, 40(12):  2804-2810 . 
    Abstract ( 1188 )   PDF (411KB) ( 889 )   Save
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    To investigate whether hybrid of Brassica crops has heterosis in photosynthetic capacity and reveal the mechanisms involved. The reciprocal inter-subspecific hybrids between Brassica campestris ssp. chinensis ‘Aijiaohuang’ and B. campestris ssp. rapifera ‘Baimanjing’, and their parents were used to determine several photosynthetic processes by simultaneous measurement of leaf gas exchange and chlorophyll fluorescence parameters. Results showed that the net CO2 assimilation rates (Pn) of hybrids were significantly higher than their parents throughout the experiment, leading to a strong heterosis in photosynthesis. Hybrids also increased stomatal conductance (Gs) but had no influence on intercellular CO2 concentration (Ci) and stomatal limitation (l). The concentrations of total chlorophyll in the hybrids are between their parents resulting in a weak heterosis. Hybrids significantly increased the quantum yield of PSII electron transport (ΦPSII) which were accompanied by a similar increase in photochemical quenching (qP). Additionally, hybrids also had evident heterosis in the maximum carboxylation rate of Rubisco (Vcmax) and the capacity for ribulose-1,5-bisphosphate regeneration (Jmax), and the values were close to the high value parent ‘Aijiaohuang’ except for the significant higher Vcmax of the direct cross between ‘Aijiaohuang’ and ‘Baimanjing’.
    Interaction between Cryptococcus laurentii, Monilinia fructicola and sweet cherry fruit at 25 and 1°C
    Scientia Agricultura Sinica. 2007, 40(12):  2811-2820 . 
    Abstract ( 1429 )   PDF (587KB) ( 1144 )   Save
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    The present study is mainly to investigate the antagonist-pathogen-host interactions in wounds of sweet cherry fruit. Antagonistic yeast Cryptococcus laurentii could significantly reduce the brown rot of sweet cherry fruit, caused by Monilinia fructicola, at 25 and 1°C. Populations of the yeast increased faster in the presence of pathogen at first, but then rapidly induced. In fruits inoculated with M. fructicola alone or combined with C. laurentii, an induction of lipid peroxidation and activities of antioxidant enzymes such as SOD, CAT, and POD was observed. Isoenzyme pattern of PPO changed greatly after the symptoms developed and new PPO isoforms were induced. By contrast, the induction of lipid peroxidation and activities of antioxidant enzymes such as SOD, CAT, and POD was weak and no significant change was found in PPO isoenzyms.
    Infrared Spectroscopy Study on the Crystal Structure of Modified Starch
    Scientia Agricultura Sinica. 2007, 40(12):  2821-2826 . 
    Abstract ( 1097 )   PDF (419KB) ( 1642 )   Save
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    【Objective】The objective of this paper is to characterize the aggregation state structure of modified starch using the infrared spectrometry.【Method】For the 1300–800 cm-1 region, the FTIR spectra of modified starch were deconvoluted Voigt-type equations for all found peaks. The areas of deconvoluted peaks at approx. 1047, 1022 and 980 cm-1 were obtained and the surface ratio of 980/1022, 980/1047, (980+1047)/1022 and 980/(1022+1047) cm-1 were analyzed for the effect of modification on the starch crystalline structure. Then the result was compared with that of X-ray diffractometry.【Result】The results indicated that acetification induced a decrease of starch crystallinity and the crystal structure changed from A-type to V-type, but the cross-linking of POCl3 had little effect on the starch crystal structure.【Conclusion】The results suggest that the infrared spectrometry can characterize the chain structure of modified starch as well as the aggregation state structure for the agreement of the results of the X-ray diffractometry.
    Effect of Nitric Oxide treatment on ethanol metabolism and relative appearance quality of Dong Jujube during Storage
    Scientia Agricultura Sinica. 2007, 40(12):  2827-2834 . 
    Abstract ( 1193 )   PDF (477KB) ( 807 )   Save
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    【Objective】This paper investigated effect of nitric oxide(NO) treatment on ethanol metabolism and relative appearance quality of Dong Jujube during storage. The action mechanisms of browning and softening are explored so as to provide theoretical base for storage of Dong Jujube.【Method】Dong Jujube fruit were fumigated with different concentrations of nitric oxide gas (10、20、30 µL·L-1) under the non-oxygen environment. The changes of correlative parameters with appearance quality, the contents of pyruvate, ethanol, acetaldehyde, and the activities of alcohol dehydrogenase (ADH) and lactate dehydrogenase (LDH) were all investigated.【Result】The contents of pyruvate, ethanol, and acetaldehyde were obviously reduced, and the content peak of pyruvate was delayed by 20 µL·L-1 NO treatment. The activities of ADH and LDH were also inhibited significantly. However, the fermentation and softening of Dong jujube fruit was promoted by 30 µL·L-1 NO treatment during storage. 【Conclusion】This study indicates that 20 µL·L-1 NO treatment may mitigate the injury of ethanol on Dong Jujube and availably control the fruit browning and softening during storage.
    Advances of the researches on the factors affecting meat tenderness and techniques for beef tenderization
    Scientia Agricultura Sinica. 2007, 40(12):  2835-2841 . 
    Abstract ( 1089 )   PDF (374KB) ( 1375 )   Save
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    As one of the key components of meat quality, tenderness has been the focus of meat sciences for years. This review discussed the possible physical and chemical mechanisms underling myofibrils and connective tissue on meat tenderness. The updates of techniques for beef tenderization were also introduced.
    ANIMAL SCIENCE·VETERINARY SCIENCERE·SOURCE INSECT
    Determination of the Geographical Origin of Beef Using Multi-element Analysis
    Scientia Agricultura Sinica. 2007, 40(12):  2842-2847 . 
    Abstract ( 1246 )   PDF (295KB) ( 1655 )   Save
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    【Objective】To investigate the feasibility of multi-element analysis in determination of the geographical origin of beef in China, and preliminarily screen the effective tracers for beef origin assessment. 【Method】Contents of such elements as Na、Mg、Al、K、Ca、V、Mn、Fe、Co、Ni、Cu、Zn、Ga、As、Se、Sr、Zr、Mo、Sn、Sb、Ba、Pb were determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in 61 de-fatted beef samples, which originated from Jilin, Guizhou, Ningxia, and Hebei province. The data was analyzed by analysis of variance (ANOVA), principal component analysis (PCA), cluster analysis (CA) and discriminant analysis (DA). 【Results】The contents of Mn、Fe、Co、Zn、Ga、As、Se、Sr、Ba and Pb were the highest in the samples from Hebei province, the content of Ni was the highest in those from Jijin province, while the contents of K、Mo and Sb were the highest in those from Guizhou province, and those of Na and Ca were the highest in those from Ningxia province. The samples of de-fatted beef were classified into catalogs by PCA and CA, which was consistent to the geographical origin. Contents of five elements of Se、Sr、Fe、Ni and Zn were selected by DA and suggested as better tracers for beef origin assessment, by which, a 100% correct classification was achieved for samples from Jinlin, Guizhou and Hebei province, a 91% correct classification for samples from Ningxia province, and 98.4% correct classification for all samples from four different regions. 【Conclusion】It is feasible to determine the geographical origin of beef by the technology of multi-element analysis.
    Growth Hormone-Releasing Peptide-2 may accelerate Growgh Hormone Release of the Swine Pituitary Cells in vitro
    Scientia Agricultura Sinica. 2007, 40(12):  2848-2852 . 
    Abstract ( 1372 )   PDF (318KB) ( 1081 )   Save
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    Swine pituitary cells were isolated from three-day new born piglet and incubated with DMEM medium in the plating culture method. These cells were treated with GHRP-2 with different concentrations, 0, 10-5, 10-6, 10-7, 10-8 and 10-9 mol/L, for 2 hours.respectively. The results showed that GHRP-2 of 10-5, 10-6, 10-7, 10-8 and 10-9 mol/L all could stimulate the pituitary cells incubated in vitro to excrete GH (P儸 0.05), and the difference among the groups was not significant (P>0.05). Furthermore the swine pituitary cells were treated with GHRP-2 of 10-6 mol/L for 5 to 180 minutes, which showed that GH value were up to peak within 10 to 20 minute. On the other hand, the swine pituitary cells were treated with GHRP-2 of 10-6 mol/L for six times in succession, each time for one hour. The results demonstrated that GHRP-2 could accelerate the release of GH in the first three times, however, the secretion was restrained after the fourth time and the negative influence increased by more treat time. But the identity of the configuration and density of swine pituitary cells observed in microscopes indicated that the succession treated with GHRP-2 could desensitize the swine pituitary cells.
    Research on relationship between beef marbling standard and fatty acid composition of longissimus dorsi
    Scientia Agricultura Sinica. 2007, 40(12):  2853-2860 . 
    Abstract ( 1202 )   PDF (268KB) ( 929 )   Save
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    Thirty six beef longissimus dorsi from bulls of Chinese Yellow Cattle with marbling grade of 2, 3, and 4 were used to determine fatty acids changes with different intramuscular fat content. The results obtained show a great variability in the content of water and intramuscular fat and the percentages of fatty acids. Water content and intramuscular fat content (IMF) correlated with beef marbling. In intramuscular fat and subcutaneous fat as well, 18:1cis-9, which is one of the monounsaturated fatty acids (MUFA), was the main fatty acid, followed by two saturated fatty acids (SFA), 16:0 and 18:0. The percentage of polyunsaturated fatty acids (PUFA) was relatively lower. Percentages of 16:0, 18:0 and SFA did not correlate with IMF, which showed that percentage of 16:0, 18:0 and SFA in beef longissimus dorsi were absolutely the same with subcutaneous fat. Percentages of 18:1cis-9, MUFA and ratio of M/S were positively correlated with IMF, with beef marbling increased from Grade 4 to Grade 2, percentages of 18:1cis-9 and MUFA and the ratio of M/S increased. However, percentages of 18:2cis-9,12, PUFA and n-6PUFA and the ratio of P/S, n-6/n-3 were negatively correlated with IMF, and with beef marbling increased, percentages of 18:2cis-9,11, PUFA, n-6PUFA and the ratio of P/S, n-6/n-3 decreased significantly. Composition of n-3PUFA in subcutaneous fat was lower significantly than that of beef intramuscular fat.
    Study on Microstructure and Ultrastructure of spleen and 5-HT Distribution in spleen of Ostrich Chick
    Scientia Agricultura Sinica. 2007, 40(12):  2861-2868 . 
    Abstract ( 1381 )   PDF (1084KB) ( 1781 )   Save
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    Construction of DNA Vaccines for Haemonchus contortus and the Protective Effects in Goats
    YAN Ruo-feng
    Scientia Agricultura Sinica. 2007, 40(12):  2869-2875 . 
    Abstract ( 1330 )   PDF (394KB) ( 1022 )   Save
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    Abstract: 【Objective】To construct DNA vaccines for Haemonchus contortus (H. contortus), and test the protective effects in goats. 【Method】Three gene fragments encoding parts of H. contortus H11, named as H11-1, H11-2 and H11-3, were insert into pcDNA4/His Max C, respectively. And the recombinants were identified by double restriction enzyme digestion and sequence analysis. Lambs were immunized with DNA vaccines about 28 and 14 days before challenged by 10000 H. contortus L3. The expressions of vaccines in goat were tested by RT-PCR and Western blotting. And the IgG stimulated by the vaccines were checked by ELISA. After challenged with L3, EPG (eggs per gram feces), L3 hatched from eggs and worm burdens of lambs were counted, respectively. 【Result】 Transcriptions and translations of the vaccines in goat muscles were conformed at 7 days post primary immunization and 1 week after boosting. And the serum anti-H11 antibodies could be inspected by ELISA about 10 days after first immunization. After challenged with L3, it was found that EPG, percents of L3 hatched from eggs and worm burdens of lambs, immunized with H11 DNA vaccines were reduced 58.75%, 72.57% and 68.25% respectively, compared with the goats administered with pcDNA4/His Max C. 【Conclusion】 The results showed us that the recombinant plasmids carry H11 gene could protect lambs from the infection of H. contortus effectively.
    Construction of Gene Targeting Vector of Tetrahymena Thermophila and Its Transformation in the Parasite
    Scientia Agricultura Sinica. 2007, 40(12):  2876-2881 . 
    Abstract ( 1083 )   PDF (543KB) ( 1383 )   Save
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    【OBJECTIVE】 The aim is to construct a gene targetting vector suitable to Tetrahymena thermophila and integrate it into the genome of T. thermophila. The characteristics of transformants were analyzed. 【METHOD】 A gene targetting vector was constructed, in which existed a neo (neomycin) gene fragment encoding paromomycin resistance used as the selected marker, as well as the 5’ and 3’ untranslated region of histone H4-I gene flanking the neo gene in the insert.The 5’ flanking region had the initiation codon ATG, and the 3’ flanking region initiated with the termination codon TGA of H4-I gene. This vector was transformed into T. thermophila by electroporation and integrated into the genome of Tetrahymena by homologous recombination. The integration of neo gene had been identified through the paromomycin selection and PCR amplification. Morphology of the transformants was investigated under optical and scanning electron microscope. [RESULTS] A gene targetting vector suitable to Tetrahymena thermophila was successfully constructed. The growing speed of the resistant cells was faster than that of the original ones, and the sizes of formers were only 1/20~1/30 of the latters. The surface of resistant cells became smooth, while a large amount of cilia were discovered on the outer surface of the original ones. 【CONCLUSION】A transformation vector suitable to Tetrahymena were constructed. The neo gene in this vector was integrated into the genome of cells by homologous recombination. The study will be helpful for developing a high efficient expression system and investigating heterologous gene expression.
    The inhibitory effects of the corresponding dsRNA of gp64 gene on the replication and multiplication of BmNPV
    Scientia Agricultura Sinica. 2007, 40(12):  2882-2887 . 
    Abstract ( 1414 )   PDF (314KB) ( 1041 )   Save
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    【Objective】To investigate the inhibitory effects of the different corresponding dsRNAs of gene gp64 on the replication and multiplication of Bombyx mori nuclear polyhedrosis virus(BmNPV).【Method】DsRNA are synthesized in vitro .Using the methods of measuring virus titer and real-time fluorescent quantitative RT-PCR, we test the interference effect of the different target domain, or length of gp64 gene.【Result】The maximum inhibitory effect of the three dsRNAs fragments (about 400bp) show no obvious difference (the maximum distinction of virus titer TCID50 is about 3.50).The inhibitory effect of dsRNA with about 100bp length is equal to those of with about 400bp length. At different period of RNA interference, the expression level of gp64 mRNA are downregulated (P<0.01). At 48 hpt, the expression amount of gp64 mRNA is about 1/300 of the control .【Conclusion】The six dsRNAs studied can inhibit the expression of viral gene and the multiplication of BmNPV. The best target site of RNAi is located at 1390~1499 in gp64 ORF.
    RESEARCH NOTES
    Effects of Wx protein Lacking on Starch Physiochemical Properties and Noodle Quality
    Scientia Agricultura Sinica. 2007, 40(12):  2888-2894 . 
    Abstract ( 1303 )   PDF (318KB) ( 1203 )   Save
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    The contents of enzyme and amylose, affected by Wx protein deficiencies significantly, were increased correspondingly with Wx protein number. In contrary, flour swelling power and starch pasting peak viscosity decreased, while noodle quality was not consistent with Wx protein lacking. Most starch physiochemical properties of waxy cultivars were lower significantly than that of other types. Different Wx subunit influenced starch physiochemical properties and noodle quality differently, and the Wx-B1 subunit lacking had greatest effect on amylose synthesis, then the Wx-D1 subunit lacking, and the Wx-A1 lacking least. The cultivar null in Wx-B1 subunit, with lowest amlose content and highest flour swelling power and peak viscosity, scored highest in noodle quality among three types with each subunit lacking. Conduced from the cultivars with different Wx protein composition, noodle score was not linear correlated to amylose content, flour swelling power and peak viscosity, especially for amylose content. Therefore, the cultivar suitable to make noodle should be confined in reasonable amylose content, and both flour swelling power and peak viscosity and noodle score increased with the decrease of amylose content between the confine, as well as noodle quality, while noodle score decreased beyond the confine.
    Using Derived Varieties of Nongken 58 to Study Yield and Morphological Characters Development of Late Japonica Rice in Zhejiang Province
    Qian Qian
    Scientia Agricultura Sinica. 2007, 40(12):  2903-2909 . 
    Abstract ( 1519 )   PDF (347KB) ( 1079 )   Save
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    In order to study the development of yield and morphological characteristics of late japonica rice in Zhejiang province, late japonica variety Nongken 58 and its 18 derived varieties were grown at China national research institute farm in Zhejiang province during 2003 and 2004. The results were as follows: (1) the yield of late japonica rice in Zhejiang province increased greatly in 1960 s’, the varieties released at this stage could be divided as large panicle number and numerous grain type or panicle number type, the yield of late japonica rice after 1970s’ increased slowly, most of the varieties released at this stage were large panicle number and numerous grain type. (2) In plant morphological characters, compared to the former varieties (released before 1985), the latter varieties (released between 1985-1995) had short flag leaf length, small leaf original angle, longer third leaf length and wide flag and third leaf width; in stem and panicle characters, the plant height, internode length of the latter varieties were shorter than that of the former varieties, but in term of stem density, sheath weight and grain density per panicle, the latter varieties were larger than the former varieties. (3)Correlate analysis show there were significant negative correlations between length of the upper 2 leaves, original angle, leaf curvature, length of the upper 2 internodes and grain yield, positive correlations exist between 3rd leaf length, leaves width, biomass yield, seed setting rate and yield.
    Changes of Carotenoid Content in Pulp of Different Loquat Types during Fruit Coloring
    Scientia Agricultura Sinica. 2007, 40(12):  2910-2914 . 
    Abstract ( 1090 )   PDF (327KB) ( 1192 )   Save
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    【Objective】The study aimed at the reason of color difference between two pulp types by investigating the changes of their carotenoid component amounts during fruit coloring.【Method】 Carotenoid components in cultivars of Daohongpao and Qingzhong that belong to two different Loquat pulp types were extract, purified and determined using HPLC since the start of fruit coloring, 【Result】The results were as follows: Lutein content of pulp decreased rapidly at first and then slowly, however, the amounts of the other 4 carotenoid compositions increased gradually, and went up quickly 7-14 days before maturation. 【Conclusion】 Carotene content, especially β-carotene content, was the major carotenoid component affecting pulp color levels between the two cultivars of ‘Daohongpao’ and ‘Qingzhong’ .
    Structural Analysis of the Introns in Cucumber CSHSP70 Gene
    Scientia Agricultura Sinica. 2007, 40(12):  2915-2919 . 
    Abstract ( 1336 )   PDF (273KB) ( 886 )   Save
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    【Objective】Introns widely exist in the DNA region of non-encoding proteins and it could effectually regulate the gene expression in the eukaryote. The objective of this paper is to study the number and structure of the introns of the chloroplastic stroma HSP70 (CSHSP70) gene in the cucumber. 【Method】Primers were designed according to the cDNA sequence from cucumber CSHSP70 gene and cucumber CSHSP70 gene was cloned from gDNA with polymerase chain reaction (PCR) technique. The existence of introns was proven by reverse transcription polymerase chain reaction (RT-PCR) technique. 【Result】After sequencing the three fragments cloned from cucumber CSHSP70 gene, a 4056bp cucumber CSHSP70 gene with seven introns was obtained. Analysis of those introns indicated that they are rich in A•T, have similar structure of promoter and core structure of the HSE. Comparative analysis of the CSHSP70 sequence in cucumber, melon and luffa indicated its nature of conservative among those cucurbit crops. 【Result】The results obtained in this study are useful in revealing the introns function of the cucumber CSHSP70 gene and understanding the molecular mechanism of heat injury and heat tolerance.
    Study on methods for preparing acellular matrices of sheep carotids
    Scientia Agricultura Sinica. 2007, 40(12):  2920-2925 . 
    Abstract ( 1303 )   PDF (382KB) ( 1115 )   Save
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    Abstract: 【Aim】 To test the feasibility of preparing acellular matrices of sheep carotids with enzyme-eradicator method, explore a new method, prepare good acellular matrices of sheep carotids, and provide scaffolds for constructing tissue-engineering blood vessels. 【Method】 Repeated freezing-thaw ─ 1%Triton X-100 + PMSF method and 0.25% trypsin ─ 1%Triton X-100 method were used for preparing acellular matrices of sheep carotids. The Specimens were observed with eyes, optical microscope and scanning electron microscope, measured for mechanic properties and compared.【Result】The repeated freezing-thaw ─ 1%Triton X-100 + PMSF method not only entirely removed the cells of samples and maintained the normal structure of matrix fibre in samples, but also the acellular matrices prepared with it maintain good shape and mechanical properties. Though the 0.25% trypsin ─ 1%Triton X-100 method entirely removed the cells of samples, but the acellular matrices prepared with it did not maintain shape and strain, with dent. 【Conclusion】 Compared with the 0.25% trypsin ─ 1%Triton X-100 method, the repeated freezing-thaw ─ 1%Triton X-100 + PMSF method is a better and new method for preparing acellular matrices of sheep carotids
    The Comparison of SSR, AFLP and RAPD Markers for Genetic Analysis of Domestic Silkworm
    Scientia Agricultura Sinica. 2007, 40(12):  2926-2930 . 
    Abstract ( 1492 )   PDF (265KB) ( 1162 )   Save
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    【Objective】It can provide the reference for selecting appropriate marker system for germplasm resource research through the studies of its suitable domain respectively of RAPD, AFLP and SSR marker systems in domestic silkworm (Bombyx mori) genetics research. 【Method】 RAPD, AFLP and SSR were used to study the genetic diversity index of 15 B.mori strains. And the three marker systems were compared. 【Result】 The results indicated that SSR presented the highest expected heterozygosity (0.40). While the lowest values of expected hererozygosity were obtained from AFLPs, which nevertheless obtained the highest marker index (MI, 15.60) and value of assay efficiency (Ai, 74.75). 【Conclusion】SSRs had higher information content than RAPD and AFLP, so it is adapted to genetic analysis of germplasm. AFLP had higher assay efficiency, i.e. it can assay more DNA bands in one PCR amplification, so it is suitable for identification and protection of germplasm and construction of genetic linkage map.