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Table of Content

    02 April 2011, Volume 44 Issue 7
    Karyotypes of Maize and Its Relatives—Teosinte
    YANG Xiu-yan, CAI Yi, FU Jie, TANG Qi-lin, RONG Ting-zhao
    Scientia Agricultura Sinica. 2011, 44(7):  1307-1314.  doi:10.3864/j.issn.0578-1752.2011.07.001
    Abstract ( 454 )   PDF (1093KB) ( 890 )   Save
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    【Objective】 Karyotypes from maize and teosinte of the current classification of Zea were investigated in order to further reveal the evolution and genetic relationships between species. 【Method】 The number of chromosomes in maize and teosintes was calculated by a root tip squashing method, and karyotypes of all species of Zea were analyzed. 【Result】 The results were as follows: All the materials are diploids with 2n=2x=20, except Zea perennis (2n=4x=40). The variation of karyotypes within subsection and species (subspecies) was not observed. The chromosomes of all the materials were metacentric or submetacentric. Except for Zea perennis which had two pairs of satellites, the other species (subspecies) only had one pair, and the satellite was located on the short arm. The satellite of maize was positioned on the metacentric chromosome, while the satellites of teosinte were located on the submetacentric chromosome. The karyotypes of all the taxa in Section Luxuriantes were 2A, while that of Section Zea were 2B type. 【Conclusion】 Cytogenetic evidence showed that all the materials of the genus Zea are diploids with 2n=20 chromosomes, except Zea perennis (2n=4x=40), the difference in variation of karyotypes between maize and teosinte is small, and they are congeneric. Zea perennis is not evolved from the double Zea diploperennis and they are two separate species.
    Monitoring of Rape Seed Germination and Seedling Emergence After Long-Term Storage in the National Crop Genebank of China
    CHEN Bi-yun; ZENG Chang-li;LU Xin-xiong; FU Zhong; CHEN Xiao-ling; WANG Hong-feng; ZHANG Tian-yao; WU Xiao-ming
    Scientia Agricultura Sinica. 2011, 44(7):  1315-1322.  doi:10.3864/j.issn.0578-1752.2011.07.002
    Abstract ( 339 )   PDF (551KB) ( 448 )   Save
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    【Objective】The objective was to study seed germination and seedling emergence of rape accessions stored in the National Crop Genebank of China (NCGC), and to realize the key factors on germinating ability variation of seeds including initial germination percentage level and storage-time, and to assess the effect of storage on rapeseed wild relatives, and to provide a scientific basis for monitoring seed viability and making renewal protocols of rapeseed and other crops stored in the NCGC. 【Method】 Seed germination and seedling emergence of 347 rapeseed accessions stored in the NCGC for 8-22 years were monitored. The effect of storage on stored seeds of different initial germination percentages, storage-time and germplasm-type were analyzed with Pearson Correlation, T-test and One-way ANOVA by the software SPSS 10.0.【Result】The results showed that after 8-22 years’ storage in the NCGC, more than 83.6% of the 347 monitored accessions of rape seeds maintained a germination percentage above 85%, the lowest initial viability standard for rape cultivated species seeds when put into a low-temperature genebank. The germination percentage of 29 accessions, accounting for 8.3% of the total, declined significantly from above 80% to below 70%. The germination percentage of 142 accessions, accounting for 40.9% of the total, declined significantly (α=2.5%).The ratio of significant declining (α=2.5%) of germination percentages increased along with the declining of initial germination percentage level or with the extending of storing-time of rapeseed as a whole. After above 15 years of storage, the seed germination percentage of rape accessions stored in the NCGC significantly declined. The ratio of significant declining of germination percentages of rapeseed wild relatives was remarkably higher than that of cultivated rapeseed species.【Conclusion】For the safe storage of germplasm resources, the initial germination percentages standard should be above 95% for most of the rapeseeds in the NCGC. The seeds of wild rape relatives or that being stored for above 15 years in the NCGC should be monitored intensively and arranged timely for breeding.
    Full-length cDNA Cloning and Expression Analysis of RPT4 in Anther of Kenaf (Hibiscus cannabinus L.)
    LIGang1;2;GUANHe-xin1;NIUYing3;ZHOUQiong1;ZhouRui-yang1
    Scientia Agricultura Sinica. 2011, 44(7):  1323-1330.  doi:10.3864/j.issn.0578-1752.2011.07.003
    Abstract ( 250 )   PDF (754KB) ( 447 )   Save
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    【Objective】 This study aims to clone the full-length cDNA of the corresponding gene of RPT4 that with differential expression between cytoplasmic male sterile (CMS) lines and their maintainers in kenaf (Hibiscus cannabinus L.) and to analyze its expression in anthers. 【Method】 With homology cloning approaches coupling with RACE techniques, the full-length cDNA of RPT4 was cloned from total RNA of the anthers of the maintainer line L23B in kenaf. Then the expressions of mRNA in the anthers before abortive stage, at abortive stage, and late abortive stage were analyzed by semi-quantitative RT-PCR. 【Result】 The longest 1197 bp ORF of RPT4 was detected from the cloned sequence with full-length of cDNA of 1 596 bp. The encoded peptide of 398 amino acids shares 91.93% homology with the one in Ricinus communis. It also contains conserved domain consisting of three motifs- Walker A, Walker B and arginine finger, which suggests that the domain has various important functions. RTP4 was confirmed to express in anthers of both CMS line L23A and its maintainer. The expressing level of RPT4 in the CMS line L23A was identical to that in the maintainer L23B at the tetrad stage. However, the expressing level of RPT4 in L23A was lower at the uninucleate (abortive) stage, and higher at the binucleate (late abortive) stage than that of L23B. 【Conclusion】 RPT4 is involved in the development of microspores in kenaf and may be related to CMS with complex molecular function.
    Construction and Analysis of Roots Suppression Subtraction Hybridization cDNA Library After Tobacco Topping
    QI Yuan-cheng; MA Lei; WANG Fei-fei; LIU Wei-qun;
    Scientia Agricultura Sinica. 2011, 44(7):  1331-1337.  doi:10.3864/j.issn.0578-1752.2011.07.004
    Abstract ( 254 )   PDF (630KB) ( 299 )   Save
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    【Objective】 This study was carried out to construct suppression subtractive hybridization(SSH) library of tobacco roots after topping and to search some candidate genes involved in regulation of nicotine biosynthesis. 【Method】 An sSSH library was constructed using cDNA from control tobacco plants as driver and those from topped tobacco plants as tester. The positive clones were selected and further screened by reverse-northern blotting, and significantly differently expressed clones were sequenced and analyzed by bioinformatics. 【Result】 The SSH library was constructed successfully. The insert size of positive clones was 200-1 000 bp confirmed by PCR. After reverse-northern blotting further screening, 560 significantly differently expressed clones among 850 positive clones were acquired, sequenced and 273 high quality expressed sequence tags (ESTs) were acquired. The results of nucleotide blast homological analysis indicated that these ESTs mainly involved in alkaloid biosynthesis (4%), plant hormone metabolism (3%), signaling/transcription (18%), stress/defense (32%), protein metabolism (9%), carbon metabolism (6%), other metabolism (15%) and function unknown (13%). The RT-PCR result of NTAT84 and NTAT71 indicated that their transcription amount increased after tobacco topping. 【Conclusion】 The SSH library of tobacco roots after topping were well constructed, and thus a basis for screening candidate genes involved in regulation of nicotine biosynthesis has been established by the information generated in this study.
    Applications and Prospects of Surface Modeling Method in Digital Plant
    WEN Wei-liang, GUO Xin-yu, LU Sheng-lian, XIAO Bo-xiang, ZHAO Chun-jiang
    Scientia Agricultura Sinica. 2011, 44(7):  1338-1345.  doi:10.3864/j.issn.0578-1752.2011.07.005
    Abstract ( 305 )   PDF (710KB) ( 417 )   Save
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    Surface modeling methods have been widely used in 3D plant modeling. In this paper, the progress for plant surface modeling in recent years was reviewed. The key approaches used in plant surface modeling were classified by parametric surface modeling, implicit surface modeling, etc. The respective advantages of plant modeling corresponding to different approaches were analyzed. Some methods that could be considered in plant surface modeling in polygon based mesh modeling method were discussed as well. Finally, the combination between surface modeling method and the research of digital plant were prospected.
    Technological Characteristics and Quantitative Analysis of Conservation Tillage in Paddy Field of Southern China —A Case Study in Double Cropping Rice Regions of Hunan Province
    LI Yuan-yuan; CHEN Yuan-quan; YANG Guang-li ; XIAO Xiao-ping ; TANG Wen-guang ; TANG Hai-ming ; SUI Peng; GAO Wang-sheng
    Scientia Agricultura Sinica. 2011, 44(7):  1346-1357.  doi:10.3864/j.issn.0578-1752.2011.07.006
    Abstract ( 298 )   PDF (352KB) ( 239 )   Save
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    【Objective】 Five conservation tillage patterns in double cropping-rice regions of Hunan were analyzed in order to find the advantages and disadvantages of them. 【Method】 Based on the five principles (less soil disturbance, less bareness, less pollution, higher soil stores, higher economic benefits), a set of indexes were built to analyze the characters of the five conservation tillage patterns contrasted with double cropping rice winter fallow (CK) . 【Result】 The main results showed that the conservation degree value of double rice-potato was the highest (reached 20.1), the double rice-ryegrass and double rice-rape reached 17.5 and 16.0, respectively. The conservation degree value of double rice-milk vetch was 10.5. The lowest values was 3.4 which was no-tillage double cropping rice pattern. 【Conclusion】 The results demonstrated that the conservation degree value of double rice-potato was the highest and adapt to the regions have surplus labor forces cause of it obtained the highest economic benefits, soil savings and labor consumption. The conservation degree value of double rice-ryegrass had the same efficient as double rice-rape and both had low labor consumption and high economic benefits. The conservation degree value of double rice-milk vetch was very high for it had the lowest pollution of pesticides and fertilizers to the environment. The no-tillage double cropping rice owned the lowest labor consumption, though its conservation degree value was the lowest, it showed its positive effects and can be popularized in the regions lack of labor forces.
    Monitoring Main Growth Status Parameters at Jointing Stage in Winter Wheat Based on Landsat TM Images
    TAN Chang-wei; WANG Ji-hua; ZHU Xin-kai; WANG Yan; WANG Jun-chan; TONG Lu; GUO Wen-shan
    Scientia Agricultura Sinica. 2011, 44(7):  1358-1366.  doi:10.3864/j.issn.0578-1752.2011.07.007
    Abstract ( 297 )   PDF (905KB) ( 687 )   Save
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    【Objective】As the growth status of winter wheat has an important effects on grain quality, the mechanism of monitoring winter wheat growth status using remote sensing technology should be further strengthened, thus the growing information could be provided for field production management in wheat growth season.【Method】The experiment was carried out in Jiangsu province in wheat growth season during 2007-2009 to monitor the main growth status parameters at jointing stage with landsat TM images. In the experiment, 431 points have been acquired to determin the main growth status paramenters. The satellite remote sensing data were used to monitor winter wheat growth status. The relationships between the main growth status parameters, grain quality and yield parameters at jointing stage, and between main growth status parameters and satellite remote sensing variables were analyzed. Through comparing the correlation between different remote sensing variables and main growth status parameters, some variables were chosed. The quantitative relationship models were established to monitor SPAD, biomass, LAI and LNC in winter wheat using remote sensing spectral variables derived from landsat TM images,and then the established models were evaluated by coefficient of determination (R2) and root mean square error (RMSE).【Result】At wheat jointing stage, it was feasible to monitor wheat SPAD, biomass, LAI and LNC by using the satellite remote sensing variables of B5, NDVI, DSW5 and B2, respectively. After the precision of the monitoring models tested by using independent datasets in 2007 and 2008, the models could be utilized to accurately monitor the main growth status parameters in winter wheat. Based on the monitoring models, the thematic maps were producted to monitor SPAD, biomass, LAI and LNC under different grades at jointing stage with remote sensing, so as to realize the spatial quantization expression of monitored main growth status parameters.【Conclusion】The results have provided timely agricultural information for the agronomists, agricultural sector decision makers and field managers, and is convenient to make field management measures in time.
    Effects of Temperature and Moisture on Sporulation of Diplocarpon mali on Overwintered Apple Leaves
    GAO Yue-e, LI Bao-hua, DONG Xiang-li, WANG Cai-xia, LI Gui-fang, LI Bao-du
    Scientia Agricultura Sinica. 2011, 44(7):  1367-1374.  doi:10.3864/j.issn.0578-1752.2011.07.008
    Abstract ( 373 )   PDF (711KB) ( 487 )   Save
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    【Objective】Leaf brown spot is a main disease causing defoliation of apple tree in early season. Information about sporulation condition and dynamic of the fungus on overwintered leaves is prerequisite for determining primary infection season and primary inoculum quantity, which are helpful for effectivecontrol of the disease. 【Method】Effects of temperature and moisture on sporulation of Diplocarpon mali on overwintered apple leaves were tested under controlled environments in 2009 and 2010.【Result】Results showed that the overwintered fungus produced pseudoconidia at temperature ranging from 0 to 30℃ with an optimum at 15.5℃. Being wetted or in high relative humidity environment was necessary for overwintered fungus to produce pseudoconidia. After being wetted or putting into environment with relative humidity over 97%, the fungus formed abundant pseudoconidia within 6 h. When incubated at 15 or 20℃ for more than 36 h, the overwintered fungus in wetted leaves, sampled in early March, produced few apothecium. The observed frequency of apothecium in the inspected stromas was 0.34%. However, the frequency rose to 5.4% on overwintered leaves sampled in late May, and 27% overwintered leaves borne apothecium.【Conclusion】 In spring, when the average diurnal temperature rises to or above 5℃, 5 mm rainfall would wet the overwintered leaves and stimulate the fungus to produce abundant pseudoconidia within 6 h. When the average diurnal temperature rises to 15℃, 24 hours’ rainfall would stimulate the formation of apothecium and ascospores. The two kinds of spores are pathogenic to apple leaves and provide abundant inocula for the disease primary infection.
    Gene Knockout Vector Construction and Function Assay of FvST12 in Fusarium verticillioides
    ZHANG Yue-ping1, QU Hua-xiang2
    Scientia Agricultura Sinica. 2011, 44(7):  1375-1383.  doi:10.3864/j.issn.0578-1752.2011.07.009
    Abstract ( 322 )   PDF (1103KB) ( 508 )   Save
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    【Objective】The objective of this study is to identify and analyze the STE12 homolog transcription factor gene in Fusarium verticillioides. 【Method】 The F. oxysporum Fost12 transcription factor was used as a target sequence to search its homolog by BlastP in F. verticillioides genome sequence. FVEG_05267.3, a predicted gene in F. verticillioides, was identified and it showed 98% similarity to Fost12. It was called FvST12 in this study. Based on the Double-Joint PCR, the knockout vector was constructed and null knockout mutants were generated through fungal protoplast transformation. The gene knockout mutants were confirmed by PCR and Southern blot. Furthermore, the function of the gene in F. verticillioides was systematically characterized 【Result】Compared with the wild type, Fvst12 mutant has normal growth rate, condiation, colony morphology, and stress responses (osmotic and oxidative stress) tested in this study. However, the mutant reduced the virulence on maize ear and stalk. 【Conclusion】The transcription factor FvST12 is an important virulence factor but it isn’t involved in the vegetative growth, conidiation, osmotic and oxidative stress responses in F. verticillioides.
    Construction, Expression, Purification and Insecticidal Activity Analysis of Cry3A Mutant with α-Chymotrypsin Site
    LIU Jing-guo, ZHAO Xiao-meng, YANG Ai-zhen, SHI Guang-lu
    Scientia Agricultura Sinica. 2011, 44(7):  1384-1389.  doi:10.3864/j.issn.0578-1752.2011.07.010
    Abstract ( 255 )   PDF (706KB) ( 369 )   Save
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    【Objective】The objective of this study is to construct a Cry3A mutant containing a α-chymotrypsin site, and to enhance its insecticidal activity. 【Method】 The Cry3Am was constructed by overlap PCR and the Cry3Am protein was purified. Tenebrio molitor were fed with Cry3Am and rolled oats to evaluate the toxicity of Cry3Am. 【Result】 The Cry3Am with a α- chymotrypsin site at the linker between α3 and α4 of Cry3A domain I was constructed successfully. In vitro digestion result showed that Cry3Am was easier to be digested to 55 kD fragment than Cry3A. In vivo bioassay result indicated that the toxicity of Cry3Am against T. molitor was two times stronger than that of Cry3A. 【Conclusion】 The insertion of α-chymotrypsin site resulted in the Cry3Am digested easily by α-chymotrypsin to 55 kD fragment, and enhanced the toxicity of Cry3Am to T. molitor.
    Nitrification of Main Soils in China and Its Relationship with Soil Properties
    BAOJun-dan;SHIMei;ZHANGMei-ting;LIANGDong-li;WUXiong-ping
    Scientia Agricultura Sinica. 2011, 44(7):  1390-1398.  doi:10.3864/j.issn.0578-1752.2011.07.011
    Abstract ( 353 )   PDF (752KB) ( 552 )   Save
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    【Objective】The correlation between nitrification characteristics and soil properties of thirteen main soil types in China were studied to lay a theoretical basis for the nitrogen management and environmental protection. 【Method】The changes of nitrate and ammonium contents in soil with time were determined during the process of nitrification under urea rate 0.2 g N·kg-1, moisture content 60% WHC, and temperature 25℃ in the laboratory incubation condition. The equation, NtNO=SNO /[1+EXP (a-bt)], was used to express the accumulation of nitrate with time. The maximal soil nitrification rate Kmax and nitrification time t0 were derived from the equation and used to characterize quantitatively the nitrification process in different soils. 【Result】Among tested soils, Kmax of Cumulic cinnamon soil was the highest, Loess soil was the next, and the lowest was Lateritic soil. The paddy soil had the biggest t0 , brown soil and moisture soil were the next, savanna red soil and Yuguan soil had the smallest t0. Soil Kmax had a pronounced positive correlation with soil CaCO3 contents and soil pH (P<0.05),but t0 was negatively correlated with soil pH(P<0.05). Through path analysis the calcium carbonate content was the major factor influencing Kmax, and pH affects Kmax through the indirect effects of other factors. With respect to direct effect in the path analysis, soil organic matter and total nitrogen content of soil had the most significant influence on Kmax.【Conclusion】Soil pH is the major influencing factor on t0, and soil CEC, amorphous iron and calcium carbonate content are the next, while the urea active, soil organic matter content, total nitrogen content and clay content have the least influence on t0.
    Nitrogen Use Efficiency of Wheat as Affected by Long-Term Fertilization in the Typical Soil of China
    YAN Hong-yuan; DUAN Ying-hua; XU Ming-gang; WU Li-shu
    Scientia Agricultura Sinica. 2011, 44(7):  1399-1407.  doi:10.3864/j.issn.0578-1752.2011.07.012
    Abstract ( 305 )   PDF (745KB) ( 353 )   Save
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    【Objective】The study was conducted to investigate the effect of long-term fertilization on nitrogen use efficiency (NUE) of wheat in various soil types of China, aiming to provide scientific references for establishing appropriate fertilization mode and improving NUE. 【Method】 The NUE of wheat were examined in three treatments: chemical N fertilization (N), combined chemical fertilization (NPK), and combined chemical fertilization with manure (NPKM) in four typical soils (Aqui-cinnamon soil, AC; Fluvo-aquic soil, FA; Cumuli cinnamon soil, CC; and Red soil, RS) of China. 【Result】 The NUE declined in the N treatments at all sites, with annual decreasing rate of 0.61%-2.32%. The averaged NUE was 6.5%-14.4% in the N treatments during the entire experiment periods. NUE in NPK treatments was significantly higher than that in N treatments, with averaged value of 20.5%-78.5%. Nitrogen use efficiency increase over time under long-term NPK fertilization at most sites. However, the NUE of NPK treatment showed a clearly decreasing trend in the red soil. Compared to the NPK fertilization, manure fertilization resulted in more stable NUE especially in the red soil where the averaged NUE value was 15.9% higher in the NPKM fertilization than in the NPK treatment. In addition, soil nitrogen, phosphorus, and potassium were lost under N fertilization but increased under NPK fertilization. The results indicated that balanced fertilization was beneficial to the improvement of NUE of wheat. 【Conclusion】 Long-term fertilization with single N can result in a decrease NUE of wheat. The continuous manure fertilization could not only keep well capacity of sustainable soil nitrogen supply, but also prevent soil acidification in south China.
    Characteristics of Absorption, Distribution and Utilization of 15N-Urea Applied in Different Depths in Gala (Malus hupehensis)
    LI Hong-bo, GE Shun-feng, JIANG Yuan-mao, PENG Fu-tian, WEI Shao-chong, FANG Xiang-ji
    Scientia Agricultura Sinica. 2011, 44(7):  1408-1414.  doi:10.3864/j.issn.0578-1752.2011.07.013
    Abstract ( 241 )   PDF (593KB) ( 400 )   Save
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    【Objective】The aim of the study is to provide a theoretical basis for the appropriate depth of fertilizer application for apple under field conditions.【Method】 The isotope 15N-urea trials were carried out in field conditions with three different fertilizer application depth treatments.【Result】The difference of Ndff was significant in different organs among different fertilizer application depth treatments,and the 0 cm and 40 cm treatments were obviously lower than 20 cm treatment. At the full-bloom stage, the Ndff was the highest in fine roots, and then in thick roots. During the shoot rapid-growing and fruit rapid-expanding stages, the Ndff of new organs was higher than that of the storage organs. The Ndff of fruit was the highest at fruit maturity stage. After harvest, the Ndff of storage organs was higher and the new organs were in low level. The distribution ratio of 15N was different in various organs at different phonological stages, but there was no significant difference among three treatments. With the process of growth, the ratio of 15N utilization of apple trees in different treatments increased gradually and reached the highest after harvest, and the treatment of fertilizer in 20 cm was generally higher than that in 0 cm and in 40 cm treatments. 【Conclusion】 Fertilizer application in 20 cm can enhance the absorption and ability to transfer N to apple tree,and also can increase the nitrogen use efficiency.
    Effects of Inter-Row Planting Grasses on Variations and Relationships of Soil Organic Matter and Soil Nutrients in Pear Orchard
    HUO Ying, ZHANG Jie, WANG Mei-chao, YAO Yun-cong
    Scientia Agricultura Sinica. 2011, 44(7):  1415-1424.  doi:10.3864/j.issn.0578-1752.2011.07.014
    Abstract ( 293 )   PDF (821KB) ( 410 )   Save
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    【Objective】 The purpose of this paper is to discuss the effects of inter-row planting grass (grazing) on soil organic matter and mineral elements in pear orchard. 【Method】 In 20-year-old ‘Golden Pear’ [Pyrus pyrifolia (Burm.f.). Cv. Nakai] orchard, in Daxing District, Beijing, three treatments were set up: inter-row planting ryegrass (Lolium perenne), white clover (Trifolium repens) and control for the clean tillage (CK). At the third and forth year after successive planting, the difference of soil organic matter and mineral elements content between different soil layers were measured and the relationships between soil organic matter and soil nutrients content were analyzed. 【Result】 Inter-row planting with L. perenne and T. repens could increase organic matter and organic C content in soil and regulate the carbon-nitrogen ratio. The total N, P and K, available P, K and Zn content, also alkaline hydrolytic nitrogen were improved significantly both in surface layer (0-20 cm) and the subsurface layer (20-40 cm) in the two patterns. Inter-row planting with L. perenne could benefit the ratio of C/N, and enhance the content of total N, available N, P, K and Mn, Mg. While inter-row planting T. repens could improve the content of total N and K, available Fe and Zn well. The content of most elements in plot of inter-row planting with the same grass for four years were enhanced compared with those of three years. Significant relationships were found between the soil organic matter and most of the soil mineral elements, and different inter-row planting plots had different correlation. In plot of inter-row planted with T. repens, the micro-elements had obvious role in regulating soil organic matter. While in plot of inter-row planting with L. perenne, the macro-elements had better role in enhancing soil organic matter. 【Conclusion】 When inter-row planting with L. perenne and T. repens in pear orchard with sandy soil, both soil organic matter and mineral elements content in both surface and subsurface layers were increased to different degrees, the nutrients supply ability also improved. Inter-row planting with L. perenne and T. repens for successive years had different roles in the relationship between soil organic mater and soil nutrients, the effects of inter-row planting with T. repens for successive years were much better.
    Genetic Analysis of Resistant to Powdery Mildew with Mixed Model of Major Gene Plus Polygene in Wild Melon Material ‘Yuntian-930’
    XIAN Feng; ZHANG Yong; MA Jian-xiang; ZHANG Xian; YANG Jian-qiang
    Scientia Agricultura Sinica. 2011, 44(7):  1425-1433.  doi:10.3864/j.issn.0578-1752.2011.07.015
    Abstract ( 300 )   PDF (814KB) ( 543 )   Save
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    【Objective】 The inheritance law of powdery mildew resistance in wild melon material ‘Yuntian-930’ was studied for utilizing this resistance material and providing a theoretical basis for selecting resistance gene in melon breeding. 【Method】 Six populations (P1, P2, F1, B1, B2 and F2) derived from the cross of ‘Yuntian-930’× ‘Hualaishi’ with the highest resistant germplasm ‘Yuntian-930’ and the highest susceptible germplasm ‘Hualaishi’ were used to study the inheritance of powdery mildew resistance by the mixed major-gene plus polygene inheritance mode with joint analysis method of multiple generations. 【Result】The result showed that the inheritance of powdery mildew resistance of wild melon‘Yuntian-930’fitted two pairs of additive-dominance-epitasis major genes plus additive-dominant-epitasis polygene model (E-0 model). In 2008, the major genes heritability of B1, B2 and F2 were estimated to be 73.31%, 69.15% and 97.61%, respectively, the polygene heritability to be 18.83%, 25.86% and 0, and the ratios of the environmental variance to phenotype variance were 2.39%-7.86% in the plastic greenhouse. In 2009, the major genes heritability of B1, B2 and F2 were estimated to be 62.98%, 58.58% and 90.89% respectively, the polygene heritability to be 28.93%, 31.47% and 3.22%, and the ratios of the environmental variance to phenotype variance were 5.89%-9.94% in the greenhouse. 【Conclusion】 The powdery mildew resistance of wild melon ‘Yuntian-930’ was controlled by two pairs of additive-dominance-epitasis major genes plus additive-dominant-epitasis polygene, and also affected by environment. In the resistance breeding program, the selection efficiency to major gene of the F2 is the highest.
    Genetic Diversity of Juglans regia L. Cultivars Revealed by AFLP Analysis
    WANGHong-xia1;ZHAOShu-gang2;GAOYi3;ZHANGZhi-hua1;XUANLi-chun4
    Scientia Agricultura Sinica. 2011, 44(7):  1434-1442.  doi:10.3864/j.issn.0578-1752.2011.07.016
    Abstract ( 241 )   PDF (886KB) ( 484 )   Save
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    【Objective】The genetic diversity and phylogenetic relationship of walnut cultivars were discussed at the molecular level, thus providing a scientific basis for more effective protection and use of these resources.【Method】The genetic diversity and relationship of 131 Juglans regia L. cultivars were analyzed by AFLP (amplified fragment length polymorphism) -silver staining protocol. The specific bands were counted and analyzed by NTSYSpc2.11a software. 【Result】 AFLP fingerprinting of 131 Juglans regia L. cultivars with twenty pairs of EcoRⅠ/MseⅠ primers revealed a total number of 1 643 unambiguous bands, of which 1 512 ones were polymorphic and 82.15 polymorphic bands were detected by each pair of primer on average. The polymorphism frequency was 92.03%. This result showed the abundant diversities of enzyme digestion sites among Juglans regia L. cultivars. As analyzed by NTSYSpc2.11a, the similarity coefficient of 131 Juglans regia L. cultivars ranged from 0.637 to 0.928. These Juglans regia L. cultivars were divided into eight groups by UPGMA (unweighted pair group method with arithmetic aver age) based on similarity coefficient. The genetic relationship of 131 Juglans regia L. cultivars was analyzed according to the similarity coefficient. 【Conclusion】 There are rich genetic diversity and complex genetic background in walnut germplasms, but it is difficult to distinguish distinctly the precocious walnut and serotinous walnut by cluster analysis.
    QTL Analysis for Tubular Floret Number and Flower Center Diameter of Chrysanthemum
    ZHANG Fei; CHEN Fa-di; FANG Wei-min; CHEN Su-mei; ZHANG Xian-yan; YIN Dong-mei
    Scientia Agricultura Sinica. 2011, 44(7):  1443-1450.  doi:10.3864/j.issn.0578-1752.2011.07.017
    Abstract ( 254 )   PDF (606KB) ( 396 )   Save
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    【Objective】The purpose of this study is to detect main-effect QTL controlling tubular floret number and flower center diameter and provide some reference for molecular marker-assisted breeding of inflorescence traits in chrysanthemum.【Method】In this study, tubular floret number and flower center diameter of chrysanthemum were evaluated in 2008 and 2009, and QTL analysis was undertaken for the two traits based on the two-year phenotypic data in 142 F1 mapping population derived from a cross between chrysanthemum cultivars ‘Yuhualuoying’ and ‘Aoyunhanxiao’ and their SRAP-based genetic linkage maps.【Result】 The two traits of tubular floret number and flower center diameter showed continuous variation and significantly correlated with each other with Pearson correlation coefficient of 0.37 (P<0.01). The QTL analysis indicated that 2 for tubular floret number and 7 for center floret number QTL were detected based on the two-year phenotypic data. These QTL scattered on 6 linkage groups, including Y1, Y2 and Y3 of ‘Yuhualuoying’ map, and A5, A13 and A19 of ‘Aoyunhanxiao’ map, with a LOD value ranging from 2.50 to 4.18 and a contribution ratio to the phenotypic variation of 6.17%-19.95% for each QTL. TfnE1Y21 and TfnE2Y21 controlling tubular floret number as well as FcdE1Y1 and FcdE2Y1 controlling flower center diameter which were mapped in the same marker interval on the linkage groups of Y21 and Y1 in 2008 and 2009 should be the same QTL and were less affected by environment, respectively. The other QTL detected in either 2008 or 2009 were remarkably affected by environment. 【Conclusion】A total of 9 QTL were mapped for tubular floret number and flower center diameter and the major QTL little affected by environment would be of great significance for the future study of molecular marker assisted breeding program in chrysanthemum.
    Identification of Geographical Origins of Wheat with Discriminant Analysis by Near Infrared Spectroscopy
    ZHAO Hai-yan, GUO Bo-li, WEI Yi-min, ZHANG Bo, SUN Shu-min, YAN Jun-hui, ZHANG Lei
    Scientia Agricultura Sinica. 2011, 44(7):  1451-1456.  doi:10.3864/j.issn.0578-1752.2011.07.018
    Abstract ( 291 )   PDF (600KB) ( 579 )   Save
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    【Objective】 A new method was developed for identification of the geographical origins of wheat with discriminant analysis by near infrared reflectance spectroscopy (NIRS). 【Method】A total of 240 wheat kernel samples collected in 2007-2008 and 2008-2009 from Hebei, Henan, Shandong and Shaanxi provinces of China were analyzed by NIRS. After normalization, first derivative and multiplicative scattering correction (MSC) pre-treatment of wheat kernel spectral data, discriminant partial least squares analysis (DPLS) was applied to classify the geographical origins of these samples. 【Result】 There were 87.5% and 91.7% of wheat kernel samples collected in 2007-2008 and 2008-2009 were correctly classified respectively, the total correct classification of 48.3% was achieved by DPLS models developed using the samples collected in 2007-2008 harvest period to predict the geographical origin of the samples collected in 2008-2009 harvest period, and 82.5% were correctly classified by DPLS models developed using 2/3 of the total sample set to test the remaining 1/3 of the samples. 【Conclusion】There are significant differences among near infrared spectra of wheat from different origins which are influenced mainly by the varieties and annual changes, and the stability of DPLS models developed has to be improved further.
    Characteristics of ATP-CP System Status in Postmortem Muscle and Their Associations with Pork Quality Traits
    MEN Xiao-ming; DENG Bo; XU Zi-wei ; LIU Min-hua; QI Ke-ke
    Scientia Agricultura Sinica. 2011, 44(7):  1457-1465.  doi:10.3864/j.issn.0578-1752.2011.07.019
    Abstract ( 321 )   PDF (741KB) ( 548 )   Save
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    【Objective】To study the role of ATP-CP system in postmortem muscle on the formation of pork quality, this research investigated the effects of pig breeds and muscle types on ATP-CP status and their possible associations with pork quality traits. 【Method】 Longissimus dorsi (L.D.) and psoas major (P.M.) of Jinhua pure breed (JH), Zhongbai pure breed (ZB), Duroc ×Zhongbai (DZ) cross and Duroc × (Yorkshire×Landrace) (DYL) cross were sampled, and ATP-CP status (including the concentration of ADP, ATP, creatine and creatine phosphate and creatine kinase, ATPase activities) and meat quality traits (including pH45min, pH24h, shear force (SF), water-holding capacity (WHC),total protein solubility (TPS), sarcoplasmic protein solubility (SPS) and myofibril protein solubility (MPS)) were measured. The reaction process and the potentiality of ATP-CP pathway were described as M=([ATP]+[Cr]) /([ADP]+[CP]) and N=(CK+ATPase)×M, respectively. One-way ANOVA and Duncan’s test were employed to analyze the difference among different pig breeds. Independent T- test was used to analyze the difference between L.D. and P.M. 【Result】P.M. exhibited a higher CK activity, pH24h, TPS, MPS, M-value, N-value (P<0.05) and a lower pH45min, Δ pH, SF, WHC, SPS than L.D. (P<0.05), the activities of CK and ATPase activities in both L.D. and P.M. muscles, M-value and N-value in L.D. muscle but not P.M. muscle declined according to the order of JH→ZB→DZ→DYL, pH45min and ΔpH in both muscles increased according to the above order. A negative correlation between M-value and pH45min (r=-0.811, P<0.01) or Δ pH (r=-0.908,P<0.01) or between N-value andΔpH (r=-0.711, P<0.01) or pH45min (r=-0.385,P<0.05), a positive correlation between N-value and pH24h (r =0.876, P<0.01) were found in L.D. muscle. 【Conclusion】 The results indicated that ATP-CP reaction process (M) and potentiality (N) were both increased in the order of DYL→DZ→ZB→JH in L.D. muscle, reversely in P.M. muscle. In JH pigs, ATP-CP reaction process (M) and potentiality (N) of P.M. muscle are both lower than the ones of L.D. muscle, which is reverse in other pigs. And ATP-CP pathway is associated with the postmortem pH, and can alleviate the decline of pH in 24 h after slaughtering and its relationships to other meat quality traits were also found and need further to be studied.
    Genetic Variation in CAPN1 Gene and Its Association with Carcass Traits in Chinese Cattle
    WU Xiu-xiang; SHI Xue-kui; WU Hai-tao; MAO Yong-jiang; YANG Zhang-ping;LI Jun-ya; GAO Hui-jiang
    Scientia Agricultura Sinica. 2011, 44(7):  1466-1473.  doi:10.3864/j.issn.0578-1752.2011.07.020
    Abstract ( 248 )   PDF (765KB) ( 329 )   Save
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    【Objective】To explore the distribution of Calpain 1 gene (CAPN1) in Chinese south yellow cattle populations and north beef cattle populations, and to evaluate it as a candidate molecular marker associated with beef quality. 【Method】PCR-SSCP method was used to detect the polymorphism of CAPN1 in 367 heads from four cattle populations, including Leiqiong, Yunnan highpump, BMY and Chinese Simmental. The association between SNP locus and some meat straits were analyzed by general linear model (GLM) in SPSS program. 【Result】 Three genotypes, AA, AG, GG and CC, CT, TT, were detected at site A4558G and C4684T, respectively, with G as an advantageous gene at site A4558G, and A as an advantageous gene at site C4684T. Genotypic variance had significant association with shearing force strait and marbling score strait. The cattle with GG in site A4558G had lower shearing force and marbling score than others (P<0.05), while the cattle with TT in site C4684T had lower shearing force than that of CT (P<0.05) and individuals with TT had lower former PH after rowing of acid than that of CC (P<0.05). Combined-genotype analysis indicated that the cattle with GGTT had lower shearing force than that of AACC, AGCT and AACT (P<0.05) and lower score of marbling than that of the rest (P<0.05), while the score of fat color of these cattle were higher than others. But there were no significant associations between two sites and other straits. 【Conclusion】 Site C4684T and A4558G of CAPN1 gene could be used as genetic marks for beef tenderness and marbling score traits.
    Identification and Characterization of the Alternative Splicing Variants of Rat RVLG
    HUANG Wen-qiang, DONG Zhen-zhen, XING Wan-jin
    Scientia Agricultura Sinica. 2011, 44(7):  1474-1480.  doi:10.3864/j.issn.0578-1752.2011.07.021
    Abstract ( 218 )   PDF (588KB) ( 302 )   Save
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    【Objective】The objective of the study is to confirm the two fragments of introns 7 and 8 of rat RVLG (rat vasa-like gene) pre-mRNA might be alternatively spliced in the ovary, and to further reveal the potential alternative splicing isoforms of introns 7 and 8 of RVLG pre-mRNA both in ovary and testis. In this study the existence of alternative splicing in RVLG pre-mRNA will be further confirmed and the potential alternative splicing isoforms of introns 7 and 8 of RVLG pre-mRNA both in ovary and testis will be tested. 【Method】 The cDNA template was prepared by reverse transcription of total RNA extracted from the ovaries of 5 female rats and the testes of 5 male rats. Partial coding region of 620-690 bp including the initiation codon were amplified by PCR. Fourteen independently amplified fragments, 7 each from ovary and testis, were sequenced and aligned with the genomic DNA of RVLG gene to analyze the alternative splicing pattern. 【Result】 In all the 14 sequenced cDNA, two fragments, one 45 bp and another 15 bp, were found to be involved in alternative splicing patterns. Of the 7 from ovary, 5 retained the 45 bp but lost the 15 bp, 2 retained the 15 bp but lost the 45 bp. Four from testes retained the 45 bp but lost the 15 bp, 2 retained both the 45 bp and the 15 bp, and one without the 45 bp and the 15 bp. The 45 bp was identified to locate at the 5’ end of intron 7 flanked by two GT, and the 15 bp at the 3’ end of the intron 8 flanked with two AG, granting these two fragments cryptic splice site for their alternative splicing.【Conclusion】There are multiple combinations of alternative splicing patterns of introns 7 and 8 of RVLG. The in vivo canonical splicing isoform may be the one that exon 8 with the 45 bp from intron 7, but exon 9 without the 15 bp from intron 8.
    Analysis of a hAT Family Transposase Gene in Bombyx mori
    SHEN Xiao-juan1, SUN Xia1, WANG Sheng-peng2, GUO Xi-jie2
    Scientia Agricultura Sinica. 2011, 44(7):  1481-1487.  doi:10.3864/j.issn.0578-1752.2011.07.022
    Abstract ( 243 )   PDF (707KB) ( 618 )   Save
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    【Objective】The objective of this study is to analyze a latent hAT transposase gene of Bombyx mori, named as BmhAT. 【Method】Sequence homology and structural domain of BmhAT were studied using bioinformatical method, the copy number of BmhAT in Bombyx mandarin and different varieties of Bombyx mori were measured by Real-time PCR, and the relative expression of BmhAT at mRNA level in different tissues of Bombyx mori was analyzed by Real-time RT-PCR.【Result】Bioinformatical analysis revealed that BmhAT had significant homology to some hAT family transposase in sequence and contains conserved domains of this family transposase. Real-time PCR results showed that BmhAT had about 3-6 copies in Bombyx mori genome. Quantitative real-time RT-PCR results indicated that the relative expression of BmhAT to actin3 reference gene in posterior silk gland and fat body was 0.4 folds and 0.6 folds, respectively.【Conclusion】BmhAT may be an active transposase gene in Bombyx mori, encoding a new hAT family transposase of Bombyx mori.
    Immunization Against Inhibin/Follistatin to Maintain Normal Semen Quality in Boars Under Summer Heat Stress
    SHI Zhen-dan, LI Ming, LIU Li, LI Min-yi, QIN Qing-ming
    Scientia Agricultura Sinica. 2011, 44(7):  1488-1494.  doi:10.3864/j.issn.0578-1752.2011.07.023
    Abstract ( 271 )   PDF (626KB) ( 291 )   Save
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    【Objective】 This study aimed to maintain semen quality and insemination capacity, which were impaired in boars adversely affected by summer heat stress, by immunization against inhibin (IHN) and follistatin (FST). 【Method】 Twenty-one boars, which exhibited semen quality problems of decreased sperm motility in summer months, were selected and equally divided into 3 groups (n=6). Immunization procedures consisted of a primary injection (i.m.) of 2 mg recombinant IHN? α-subunit protein in 2 ml mineral oil adjuvant, and two booster immunizations with 1 mg IHN protein at 21-d intervals for Group A boars. Group B boars were similarly immunized as in Group A boars, but apart from IHN immunogen, also immunized against equal amount of FST protein on each occasion. Group C served as controls that received mineral oil adjuvant on the same occasions. In the 9-wk experimental period, blood samples were collected for measurements of antibody titres, plasma concentrations of FSH and testosterone. Semen was collected every week and examined for sperm motility and density. 【Result】 Immunization against IHN and FST significantly elevated plasma anti-IHN and anti-FST antibody titres, increased FSH and testosterone concentrations, maintained semen sperm motility and sperm density, which in the control boars decreased progressively during the experiment. 【Conclusion】Immunization against IHN and FST was capable of overcoming the adverse impact of heat stress, thus to increase FSH and testosterone secretions, and to maintain boar semen motility, density and reproductivity in hot summer months.
    Effect of CaM on Expression of Inducible Hsp70 in MEF
    ZHANG Xia; CAO Rong-feng; CONG Xia; LI Jin-bo; SUN Qi; GAO Shan-song; TIAN Wen-ru
    Scientia Agricultura Sinica. 2011, 44(7):  1495-1501.  doi:10.3864/j.issn.0578-1752.2011.07.024
    Abstract ( 277 )   PDF (595KB) ( 324 )   Save
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    【Objective】The objectives of this study were to reveal whether or not the calmodulin (CaM) gene participates in HSP70 gene expression in the mouse fetal fibroblasts and to definite their participating conditions. 【Method】 The 12.5-day mouse embryo of pregnancy was taken to culture its fibroblasts (MEF). The fibroblasts were divided into control group and heat shock group randomly. The heat shock group was further divided into groups of Ⅰ(39℃ for 0.5 h), Ⅱ(39℃ for 1 h), Ⅲ(39℃ for 1.5 h), Ⅳ(41℃ for 0.5 h), Ⅴ(41℃ for 1 h) and Ⅵ(41℃ for 1.5 h) , respectively, while the control group was treated at 37℃. Three replicates were performed for each group. The optimum heat stress group was then selected. Calmodulin antagonist W7 was applied to both the selected and control group with different concentrations (25, 50, and 100 mmol·L-1) in parallel. Both expressions of Hsp70 and CaM mRNA were detected by using the method of RT-PCR. 【Result】 The expressions of Hsp70 mRNA in both 39℃ and 41℃ groups were significantly higher than that of the control group (P<0.05). However, the expression of Hsp70 mRNA in the group treated at 39℃ for 1h was significantly higher compared with other groups (P<0.01). The expressions of CaM mRNA in the groups treated both at 39℃ for 0.5 h and 39℃ for 1 h were significantly higher than that in other groups (P<0.01). There was no difference in CaM mRNA expression in the group treated at 41℃ compared with the control group (P>0.05). The expressions of Hsp70 mRNA in the groups of 37℃ and 39℃ for 1 h treated with 100 mmol·L-1 W7 were significantly lower than that in corresponding control group (P<0.01). 【Conclusion】 There is a positive correlation between Hsp70 and CaM gene expression under moderate heat shock and the treatment at 39℃ for 1 h induced both Hsp70 and CaM gene expressions. The CaM gene participates in HSP70 gene expression.
    Short-Term Fluctuations and Risk Evaluation of Vegetables Market Price in China
    LI Gan-qiong1, XU Shi-wei1, SUN Yi-guo2, LI Zhe-min1
    Scientia Agricultura Sinica. 2011, 44(7):  1502-1511.  doi:10.3864/j.issn.0578-1752.2011.07.025
    Abstract ( 325 )   PDF (1039KB) ( 502 )   Save
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    【Objective】 Taking the monthly wholesale prices of 11 kinds of vegetables in China as the object of study, the intensity and pattern of short term fluctuation of varieties of vegetables were compared and analyzed, the yield distribution of vegetables market was estimated, and the market risk of short term fluctuation was evaluated. 【Method】 The study mainly adopted three methods of variation coefficient, hierarchical cluster and kernel density estimation to analyze short term fluctuation and yield distribution of vegetables market. 【Result】 The results are as follows: the descending order of fluctuating intensity of vegetables is eggplant, green pepper, hot pepper, garlic, cucumber, bean, spinach, rape, tomatoes, celery and cabbage. There are three patterns of short term fluctuation which are distinct wave peak and trough pattern, narrow and compact wave pattern and fluctuating cluster pattern. The yield distribution of vegetables market is asymmetric and the probability of rising of vegetables market price is higher than that of falling. The risk of spinach market price is the greatest and its probability of the rising and falling range over 30% reaches 40.48%. Following behind spinach is eggplant. The risk of garlic market price is the smallest and its probability of the rising and falling range over 30% is only 1.82%. 【Conclusion】 The overall risk of vegetables market price is high under the condition of market economy. A majority of varieties of vegetables market price are often seen ups and downs. However, the occurrence of great fluctuation of garlic market price is a small probability event. If it happened there was a reason to judge for abnormal fluctuations.
    Determination of the Content of Solanine in Potato Tuber in Yunnan
    HUANG Hong-ping, GUO Hua-chun, WANG Qiong, SHEN Ci-zhuan, ZHOU Chen
    Scientia Agricultura Sinica. 2011, 44(7):  1512-1518.  doi:10.3864/j.issn.0578-1752.2011.07.026
    Abstract ( 471 )   PDF (605KB) ( 468 )   Save
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    【Objective】 The varieties of potato in Yunnan and the solanine content in mechanical damaged potato, green potato, germinating potato, worm eaten potato and local midew potato were determined in a study to provide a theoretical basis for food safety. 【Method】 Crude solanine was extracted with ultrasonic solvent pairs extraction method. HPLC was used to determine solanine contents of 131 varieties of potato in Yunnan. 【Result】The solanine content of main cultivar in Yunnan was no more than 10 mg·(100 g)-1 FW. Only 3.12% of the old varieties were over the safe value. But the solanine content of 12.12% of varieties were over the safe value, even the highest content in some of them reached 48.59 mg·(100 g)-1 FW. Just in 30.30% the varieties, the content was in 10 to 20 mg·(100 g)-1 FW. The solanine content of mechanical damaged potato, green potato, germinating potato and local midew potato increased. 【Conclusion】 The main and local varieties of potato in Yunnan province have lower solanine content, while the solanine content in new varieties is higher than the safe level. This might be related to the genetic background. With the introduction and utilization of the potato genetic resources, the solanine content of new varieties must be as one of the quality indicators to ensure the food safety of the table potato.
    Effect of No-Tillage and Direct Sowing Density on Growth, Nutrient Uptake and Yield of Rapeseed (Brassica napus L.)
    SU Wei; LU Jian-wei; ZHOU Guang-sheng; LI Xiao-kun; HAN Zi-hang; LEI Hai-xia
    Scientia Agricultura Sinica. 2011, 44(7):  1519-1526.  doi:10.3864/j.issn.0578-1752.2011.07.027
    Abstract ( 411 )   PDF (622KB) ( 664 )   Save
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    【Objective】Understanding of the restrictive factors that can reduce rapeseed (Brassica napus L.) yield and the reasonable direct sowing density of later sown rapeseed is the key for optimizing rapeseed cultivation and management under the condition of no-tillage.【Method】 A field experiment was conducted to study the differences in condition of soil compaction and weed growth between no-tillage and conventional tillage and the effect of tillage methods on rapeseed growth, nutrients uptake and yield. At the same time the effect of different direct sowing densities on growth and nutrients utilization of rapeseed were also studied. 【Result】 The soil bulk density of no-tillage was significantly higher than conventional tillage. In the whole growth period of rapeseed, the soil bulk density of no-tillage was 0.11 g·cm-3 higher than conventional tillage, averagely. Compared with conventional tillage treatment, no-tillage was in favor of weed development, the N, P, K nutrient rates absorbed by weeds in no-tillage treatment were, respectively, 1.9, 2.4 and 2.5 times as that of conventional treatment. Compared with conventional tillage treatment, dry matter accumulation rates and N, P, K uptake rates of rapeseed of no-tillage treatment decreased averagely by 18.2%, 17.1%, 16.4% and 20.2% in the whole growth period, respectively, the yield of no-tillage treatment decreased by 10.7%, and the difference was significant. The result of direct sowing density experiment showed that compared with low sowing density treatment, total weed amount and dry matter rates of weeds of high sowing density treatment decreased by 40.5% and 56.4%, respectively; while dry matter accumulation rates and N, P, K uptake rates of rapeseed of high sowing density increased averagely by 55.3%, 46.7%, 53.6% and 50.2% in the whole growth period, respectively, and the yield of high sowing density increased by 43.1%.【Conclusion】It is concluded that under the condition of no-tillage, soil compaction and too many weeds are two serious problems, which led to decrease of rapeseed yield. Increasing direct sowing density of rapeseed under the condition of no-tillage is a very effective method to increase yield when direct sowing date is later, while in this experiment the most reasonable direct sowing density was 6×105 plant/hm2.
    The Rate of Seed Contamination and Transmission of Cucumber green mottle mosaic virus in Watermelon and Melon
    WU Hui-jie; QIN Bi-xia; CHEN Hong-yun; PENG Bin;CAI Jian-he; GU Qin-sheng
    Scientia Agricultura Sinica. 2011, 44(7):  1527-1532.  doi:10.3864/j.issn.0578-1752.2011.07.028
    Abstract ( 659 )   PDF (551KB) ( 748 )   Save
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    【Objective】The objective of this study is to strengthen detection of seeds which carry virus, and to prevent the spread and prevalence of Cucumber green mottle mosaic virus (CGMMV). 【Method】 The rate of contamination and seed-to-seedling transmission of CGMMV in watermelon and melon were evaluated by DAS-ELISA. The seeds detected in the study were harvested from fruits of infected watermelon and melon plants by inoculation in insect-proof plastic house. 【Result】 The results showed that the contamination rate and seed-to-seedling transmission rate of CGMMV in watermelon were 100% and 2.25%, respectively, by testing 250 seeds and 623 seedlings. The contamination rate and seed-to-seedling transmission rate of melon was 93.85% and 2.83%, respectively, by analyzing 130 melon seeds and 2 050 melon seedlings. In the mixtures of CGMMV infected/ healthy seeds or leaves, the sensitivity was successfully detected at ratios of 1/1 000 and 1/10 000, respectively. 【Conclusion】The contamination rate was higher than the seed-to-seedling transmission rate, which showed that the virus distributes mainly in the seed coat. The sensitivity detection indicated that DAS-ELISA could be used to detect a large number of the seeds.