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Table of Content

    01 December 2010, Volume 43 Issue 23
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
    Cloning, Prokaryotic Expression and In vitro Functional Analysis of α-Gliadin Gene from Common Wheat
    LI Min,GAO Xiang,CHEN Qi-jiao,DONG Jian,ZHAO Wan-chun,WANG Ming-xia
    Scientia Agricultura Sinica. 2010, 43(23):  4765-4774 .  doi:10.3864/j.issn.0578-1752.2010.23.001
    Abstract ( 844 )   PDF (765KB) ( 1157 )   Save
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    【Objective】 An α-gliadin gene, with an additional cysteine residue, was cloned and expressed in E. coli system. The target protein was purified by Ni+-NTA column, and then integrated into the control flour to understand the potential quality of this α-gliadin gene. 【Method】 A DNA fragment with 1 243 bp (GenBank accession GQ891685)was cloned from Shaan 253 by primers designed according to conserved domains of known α-gliadin genes. Meanwhile, the gene expression vector pET32a-S253-Agli was constructed. Fusion protein was induced in the host strain E. coli BL21(DE3)by IPTG. In order to determine its processing quality of subunit S253-Agli, the expressed product was purified and recovered by affinity chromatography and low temperature cryodesiccation, and then integrated into the control flour utilization of 4 g Micro-doughlab. 【Result】 Sequence analysis showed that the DNA fragment of this gene contained a complete 900 bp coding region and some of regulatory elements. In the deduced amino acid sequences, an extra cysteine replacement of serine at position 6, which may form an intermolecular disulfide bond, was caused by single base conversion of C/G. The fusion proteins, induced by IPTG, were confirmed by SDS-PAGE and Western-blot and mainly existed as inclusion body. The farinograph results suggested that the purified subunit S253-Agli has negative effects on flour quality because of its reduction of main parameters, including development time and stability time, although some of farinograph parameters increased significantly, such as width of curve and mixing tolerance index.【Conclusion】 It was suggested that the potential quality of α-gliadin protein encoded by gene GQ891685 increased the elasticity but decreased the strength of wheat flours.

    Effects of Biparental Mass Selection on Two Narrow-Base Maize Populations
    LI Lu-jiang,CHEN Wen-sheng,YANG Ke-cheng,PAN Guang-tang,RONG Ting-zhao
    Scientia Agricultura Sinica. 2010, 43(23):  4775-4786 .  doi:10.3864/j.issn.0578-1752.2010.23.002
    Abstract ( 730 )   PDF (488KB) ( 564 )   Save
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    【Objective】 Two synthetic narrow-base maize populations, P3C0 and P4C0, were improved by 5 cycles of biparental mass selection, the effects on the population per se and combining ability were analyzed with the objective to make suggestions on how to raise the efficiency of improvement and utilization of synthetic populations. 【Method】 In different ecological environment, the phenotype of the populations per se were analyzed, and the combining ability were tested according to an incomplete diallel model.【Result】 Most traits of the populations per se and the GCA were improved significantly, whereas the SCA of most traits showed no significant increase over biparental mass selection. For P3C0 and its improved descendants, the mean of kernel depth and rows per ear were smallest at C0 and largest at C5. The GCA effects of them were smallest at C0, and largest at C2 and C5, respectively. The yield per plant of populations per se and its GCA effects were both smallest at C0, and largest at C4 and C2, respectively. For P4C0 and its improved descendants, the mean of kernel depth and rows per ear were smallest at C0, and largest at C5 and C4, respectively. The GCA effects of them were both smallest at C0, and largest at C4. The yield per plant of the populations per se and its GCA effects were both smallest at C0, and largest at C2 and C4, respectively. For most of the other traits per se and their GCA effects, the improved descendants were larger than their respective C0. There were different effects of improvement on different populations and traits at different cycles. The general trend showed that after cycles of biparental mass selection, some traits of populations per se and their GCA were improved simultaneously, while the improvement of population per se and the GCA did not display a synchronicity for some others. After the largest selection response to biparental mass selection was obtained, a sustained biparental mass selection would lead to a decrease in genetic gain or even a negative genetic gain. In addition, the populations retained their genetic diversity over 5 cycles of biparental mass selection with a population size of 600 plants and a selective ratio of 10%. 【Conclusion】 The improvement effect of the populations should be analyzed periodically, then adjust the improvement program according to the results. It is necessary to coordinate the relationship of the directly selected traits and the remaining traits in a narrow-base population improvement program via recurrent selection. When the major traits of population per se and GCA are improved effectively, a reciprocal recurrent selection method should be employed to improve the GCA and SCA synchronously, and then the germplasm improvement could combine with hybrid breeding.
    Mining Candidate Genes for Resistance to Soybean Cyst Nematode Based on Meta-Analysis and Domains Annotations
    CHANG Wei,HAN Ying-peng,HU Hai-bo,LI Wen-bin
    Scientia Agricultura Sinica. 2010, 43(23):  4787-4795 .  doi:10.3864/j.issn.0578-1752.2010.23.003
    Abstract ( 922 )   PDF (635KB) ( 1122 )   Save
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    【Objective】This experiment was designated to mining the Heterodera glycines Ichinohe (SCN) resistcance genes, and to analyze their expression in different cultivars and different organs of the same cultivar, so as to explore the explore of these genes in the resistance reaction. 【Method】 Software BioMercator2.1 was used to integrate SCN resistance QTLs of different derived studies onto GmComposite2003, and the consensus QTLs were obtained by Meta-Analysis. Software hmmsearch was used to mine the candidate SCN resistance genes. RT-PCR and semi-quantitative RT-PCR were conducted to clone the candidate full-length SCN resistance genes, and to investigate the expression levels of these genes. 【Result】 A total of 27consensus QTLs were obtained through Meta-Analysis, which were used for resistance gene detection by the hmmsearch. A total of 77 coding sequences (SCN R-gene), located in these 27 consensus QTLs, were identified, which could be classified into 6 classes. Among these 6 classes, the PK-LRR-TM and the PK were two main types, which accounted for about 77% of all. Four genes in the resistance genes cluster of Gm16 were successfully cloned by RT-PCR method. The semi-quantitative RT-PCR showed that Glyma16g31490.1 was specifically expressed in the SCN resistance cultivar L-10 but not in Heinong 37 (cultivar susceptible to SCN), and the expression level was higher in root than that in leaf for L-10.【Conclusion】The result of sequence analysis revealed that the cloned four genes on Gm16 has a higher homology with the other PK-LRR-TM type resistance genes. Subsequent semi-quantitative RT-PCR showed that Glyma16g31490.1 was specifically expressed among different cultivars or different organs of the same cultivar, which indicated that this gene may play a role in the SCN resistance, and also proved that this method, based on Meta-Analysis and domains annotations, is an effective tool for mining SCN resistance genes.

    TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY

    Analysis on Physiological Properties of the Heavy Panicle Type of Indica-Japonica Inter-subspecific Hybrid Rice Yongyou 6

    XU De-hai,WANG Xiao-yan,MA Rong-rong,YU Sheng-miao,ZHU Lian-feng,OUYANG You-nan,JIN Qian-yu
    Scientia Agricultura Sinica. 2010, 43(23):  4796-4804 .  doi:10.3864/j.issn.0578-1752.2010.23.004
    Abstract ( 940 )   PDF (365KB) ( 965 )   Save
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    【Objective】 This study was conducted to reveal the relationship between heavy panicle, super-high-yield and physiological properties of indica-japonica inter-subspecific hybrid rice Yongyou 6. 【Method】 A continuing experiment was conducted to evaluate the temperature and light response characteristic, source-translocation-sink characteristic and other physiological properties with the heavy type of indica-japonica inter-subspecific hybrid rice variety Yongyou 6, the light panicle type of conventional late japonica rice variety Xiushui 63, and the middle panicle type of late indica hybrid rice variety, Shanyou 63 during 2003-2008. 【Result】 The results showed that compared to conventional late japonica rice Xiushui 63 (light panicle type, CK1) and late indica hybrid rice Shanyou 63 (middle panicle type, CK2), the heavy panicle type of indica-japonica inter-subspecific bybrid rice Yongyou 6 have many outstanding physiological properties as follows: (1) Strong source that characterized with larger LAI, longer functional period of leaf, higher chlorophyll content of leaf, higher photosynthetic rate of functional leaves, higher specific leaf weight and grain-leaf ratio; (2) Efficient flow that characterized with higher output, output rate and translocation rate of dry matter in single stem and sheath of rice; (3) Greater sink that characterized with increased gross spikelet number, effective spikelet number per unit area, higher yield capacity and heavier single panicle weight (about 5 g); (4) Stronger root system that characterized with developed secondary roots, more roots, higher root activity and higher root/shoot ratio which enhanced the lodging resistance and yield. 【Conclusion】 In order to increase the yield of new indica-japonica inter-subspecific hybrid rice combinations, the breeders have to cooperate with researchers of relevant subjects at the early stage during the parents selection, especially hybrid F1 selection, to evaluate the source-translocation-sink characteristic and root/shoot ratio of parents and new combinations.

    Effects of Phosphorus Placement Depth on Yield and Nutrient Uptake of Summer Maize
    ZHAO Ya-li,YANG Chun-shou,WANG Qun,LIU Tian-xue,LI Chao-hai
    Scientia Agricultura Sinica. 2010, 43(23):  4805-4813 .  doi:10.3864/j.issn.0578-1752.2010.23.005
    Abstract ( 806 )   PDF (375KB) ( 1019 )   Save
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    【Objective】 The effects of phosphorus placement depth on grain yield and nutrient uptake of summer maize were studied. 【Method】 Pot experiments and a field experiment were carried out to determine the effects of different phosphorus placement depths (T5: 5 cm, T15: 15 cm, and T5/15: 5/15 cm) on grain yield and nutrient uptake absorption and distribution of summer maize. 【Result】The grain yield and total nutrient uptake decreased in the order of T15>T5/15>T5>CK (i.e. the control treatment receiving no phosphorus). Application of phosphorus increased grain yield by 8.5%-20.0% when compared with the no phosphorus control treatment. The grain yield in the treatment of T15 was 5.9%-10.6% higher than that in treatments T5 and T5/15, the N, P and K uptake in treatment T15 was 6.9%-14.7%, 7.5%-17.1%, and 5.0%-13.4% higher than those in treatments T5 and T5/15, respectively, whereas the N, P, and K transferring rate in treatment T15 was 10.4%-17.3%, 8.4%-12.9%, and 12.9%-19.6% lower than the other two phosphorus placement treatments, respectively. The P agronomic efficiency (PAE) and P apparent utilization efficiency (PAUE) in treatment T15 were 55.8%-88.0% and 40.4%-181.4% higher than the other two phosphorus placement treatments, respectively. 【Conclusion】 Consequently, phosphorus application significantly increased the yield of summer maize. Placing all phosphorus at one deep depth resulted in better crop performance compared with splitting phosphorus at two shallow depths. Deeper placement of phosphorus is better than shallower phosphorus placement. The best phosphorus effects can be produced in maize production when all phosphorus is placed at the soil depth of 15 cm.

    Chlorogenic Acid Contents in Shoot-Tips of Different Vegetable-Use Sweetpotato Varieties and Their DPPH-Scavenging Capacities

    FU Yu-fan,YANG Chun-xian,ZHAO Ya-te,ZHAO Wen-ting,LIU Xiao-qiang,ZENG Ling-jiang,LIAO Zhi-hua,ZHANG Qi-tang
    Scientia Agricultura Sinica. 2010, 43(23):  4814-4822 .  doi:10.3864/j.issn.0578-1752.2010.23.006
    Abstract ( 870 )   PDF (291KB) ( 748 )   Save
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    【Objective】 Sweetpotato vine is composed of 3 parts, namely leaf, petiole and stem. It has received more and more attentions from the researchers, consumers, and are popular in vegetable market because sweetpotato vine is an excellent source of antioxidative polyphenolics which have anthocyanins and phenolic acids such as chlorogenic acid, and is superior in this regard to other commercial vegetables. So, the differences in chlorogenic acid contents in shoot-tips among varieties, parts and topping times of vegetable-use sweetpotato and their DPPH-scavenging capacities were studied in present paper. 【Method】 The contents and DPPH-scavenging capacities of chlorogenic acid in leaves, petioles and stems of shoot tips of 3 vegetable-use sweetpotato varieties Guangcaishu No.2, Pushu 53 and Fushu 7-6 at 6 topping times after transplanting were determined and the correlationship between the chlorogenic acid content and its DPPH-scavenging capacity was analyzed. 【Result】 The order of 3 varieties about their average chlorogenic acid contents in shoot tips during 6 topping times was Guangcaishu No.2 (0.2920%fb)>Pushu 53 (0.2750%fb)>Fushu 7-6(0.1638%fb), and the order of 3 parts of shoot tips was leaf (0.3539%fb)>stem (0.1444%fb)>petioles (0.1173%fb) and the average chlorogenic acid content in leaves was 2.70 times the average of chlorogenic acid contents in petioles and stems. The average chlorogenic acid contents during the former 3 topping times in shoot tips of Guangcaishu No.2, Pushu 53 and Fushu 7-6 were 2.22, 2.68 and 2.41 times those during the latter 3 topping times, respectively. And the average chlorogenic acid contents during the former 3 topping times in leaf, petiole and stem of shoot tips were 2.49, 2.53 and 2.20 times those during the latter 3 topping times, respectively. The above differences in chlorogenic acid content were all significant. The significant variations of chlorogenic acid contents among varieties, parts and topping times were derived partly from the variety, and the effect of part, topping time and their interactions were also significant. 73.64% of chlorogenic acid in shoot tips was distributed in leaves, 11.96% in petioles and 14.41% in stems. The order of average DPPH-scavenging capacities of shoot tips of the 3 varieties during 6 topping times was Guangcaishu No.2 (34.99%)>Pushu 53 (31.05%)>Fushu 7-6 (18.83%), and the order of 3 parts was leaf (32.52%)>stem (23.64%)>petioles (17.91%). The average DPPH-scavenging capacities during the former 3 topping times in shoot tips, leaf, stem and petiole were 1.91, 2.02, 1.69 and 1.99 times those during the latter 3 topping times, respectively. The DPPH-scavenging capacities of shoot tips, leaf, stem and petiole were all significant positively correlated with their chlorogenic acid contents. 【Conclusion】 There were significant differences in chlorogenic acid contents among different varieties, parts and topping times of vegetable-use sweetpotato and these differences had significant effects on the shoot tips DPPH-scavenging capacities. The behavior of chlorogenic acid content variation should be taken into account in the breeding, cultivation and industrialization of vegetable-use sweetpotato.
    PLANT PROTECTION

    Endophytic Bacterial Diversity Analysis of Huanglongbing Pathogen-Infected Citrus Phloem Tissue in Guangxi

    WANG Ai-hua,YIN You-ping,XIONG Hong-li,LI Yan-fang,LI Jia,XIAN Jia-xu,WANG Zhong-kang
    Scientia Agricultura Sinica. 2010, 43(23):  4823-4833 .  doi:10.3864/j.issn.0578-1752.2010.23.007
    Abstract ( 849 )   PDF (384KB) ( 1178 )   Save
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    【Objective】 The endophytic bacterial diversity in the Huanglongbing pathogen-infected and healthy citrus phloem tissue in Guangxi were investigated in order to decipher the interactions of Huanglongbing pathogen with companion microbe. 【Method】Both classical morphological, physiological, chemotaxonomic characteristics methodology and 16S rRNA, and PCR-RFLP analysis methods were applied. 【Result】 By the traditional isolation and identification and 16S rDNA amplificons methods, 10 genera of bacteria were identified from 21 culturable bacterial populations. The sequences aligned with NCBI GenBank database and showed that they belonged to 10 different genera of bacterium. The dominant bacterial population in healthy citrus belonged to Bacillus sp., Pseudomonas sp., and Kocuria sp.. While in phloem tissue of infected citrus plant over ten years were Bacillus sp., Pseudomonas sp., Kocuria halotolerans, and Microbacterium sp.. By the PCR-RFLP methods, two 16S rDNA clone libraries of endophytic bacteria were constructed and 29 restriction endonuclease types were detected, 10 genera of bacteria and 11 genera of uncultured bacteria were identified. The dominant bacterium population in libraries belonged to Dyella sp., Pseudomonas sp., Serratia sp. and uncultured bacterium. The density and species of endophytic bacteria were observed in remarkable difference compared disease tree to healthy one. 【Conclusion】 By traditional cultivation and 16S rDNA sequencing, PCR-RFLP analysis, the diversity of population and species of endophytic bacteria mainly in citrus phloem tissue has difference among infected and healthy citrus plant, while those dominant bacterial populations if related to Huanglongbing pathogen is currently still under investigation.

    Identification of Oxya-Specific SCAR Molecular Marker
    ZHANG Jian-zhen,LI Da-qi,LI Tao,MA En-bo,GUO Ya-ping
    Scientia Agricultura Sinica. 2010, 43(23):  4834-4839 .  doi:10.3864/j.issn.0578-1752.2010.23.008
    Abstract ( 782 )   PDF (441KB) ( 663 )   Save
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    【Objective】 Oxya-specific molecular marker was studied in order to provide a rapid and effective molecular identification method. 【Method】 Oxya-specific RAPD band was screened out from lots of RAPD-PCR results, the specific band was cloned and sequenced, a pair of primer was designed based on homologue region after sequence alignment. PCR was performed by using designed specific primers, genomic DNA from different Oxya species and other Acridoidea species were used as template. 【Result】 A clear and reproductive band about 650 bp amplified from random primer S823 was present in different Oxya species. Sequence analysis showed high nucleotide homology (92.3%-96.6%) among three Oxya species, each sequence determined consisted of 651-667 nucleotides, with G+C content >15% and repetitive A or T regions. Sequence characterized amplified region (SCAR) primers for specific PCR were developed, an expected specific band (550 bp) was obtained by using SCAR primers in seven species of Oxya examined but absent in Pseudoxya diminuta and other Acridoidea species. 【Conclusion】 Oxya-specific SCAR molecular marker was identified, and SCAR primers can be used for rapid identification of Oxya species.

    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Comprehensive Evaluation of Soil Quality in Different Productive Paddy Soils in Typical Double-Rice Cropping Regions of Hunan Province
    XIE Jian,ZHENG Sheng-xian,YANG Zeng-ping,NIE Jun,LIAO Yu-lin,WU Xiao-dan,XIANG Yan-wen
    Scientia Agricultura Sinica. 2010, 43(23):  4840-4851 .  doi:10.3864/j.issn.0578-1752.2010.23.009
    Abstract ( 804 )   PDF (334KB) ( 673 )   Save
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    【Objective】 A non-linear assessment model was used to quantify the changes of paddy soils with different productivities and provide a scientific basis for sustainable use of paddy soil in double-rice growing area. 【Method】 This study was conducted in important double-rice producing areas. A comprehensive method for evaluating soil quality was adopted. Soil quality was evaluated according to four major soil functions, i. e., resistance to physical degradation, nutrient supply and storage, resistance to biochemical degradation and conservation of crop productivity. Every soil function and individual soil indicator was weighted on the basis of the expert opinion panel and statistical tools such as factor analysis,then soil property values measured under different productive paddy soil were transformed into unitless scores (between 0 and 1) using non-linear score equation. The non-linear assessment model based on soil function could comprehensively evaluate the soil quality, which can be directly reflected by this method. 【Result】 Results showed that high yield paddy soils in eight experimental areas have physical, chemical and biochemical qualities. The middle yield paddy soil has good physical and biochemical qualities, but poor chemical qualities. The physical, chemical and biochemical qualities in low yield paddy soils were all poor, which mainly reflected low organic matter, nutrient supply and storage ability. 【Conclusion】 Overall soil quality of high yield paddy soil was good, which did not create obstacles to double rice growth. The main factor affecting middle yield paddy soil was unbalance of soil nutrient supply in the soil. The overall soil quality of low yield paddy soil was poor, input of increasing organic matter and inorganic nutrient is required for improvement of the overall soil quality in this type of paddy soil.

    Effects of Long-Term Fertilization on Assimilated Carbon Content and Distribution Proportion of Maize in Fluvio-Aquic Soil
    MIAO Hui-tian,ZHANG Wen-ju,Lü Jia-long,HUANG Shao-min,XU Ming-gang
    Scientia Agricultura Sinica. 2010, 43(23):  4852-4861 .  doi:10.3864/j.issn.0578-1752.2010.23.010
    Abstract ( 887 )   PDF (363KB) ( 882 )   Save
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    【Objective】 Study on the assimilated carbon accumulation and distribution of maize under various fertilizer applications in fluvio-aquic soil, can not only provide a scientific basis for rational fertilization practices for increasing crop yield, but it also has important significance to the study of global carbon cycling. 【Method】 Based on a long-term experiment, samplings from various organs of maize were taken at maturity stage to measure the biomass yield under various fertilization applications. Organic carbon content, carbon assimilate distribution proportion, and C/N ratio of maize and its various organs under different fertilization conditions were also analyzed. 【Result】 The results showed that the averaged carbon content in maize was about 464 g?kg-1 under the long term combined application of fertilizers and organic manure (NPKM, 1.5NPKM). It was 3% higher than the applications of N and PK treatments. The carbon content of maize kernel was obviously improved in the NK treatment, which was about 3% higher than the control treatment. In all treatments, the distribution proportion of assimilated carbon biomass in stem and leaf of maize was about 57% in PK treatment, which was 73% higher than that of the N treatment. The distribution proportion of assimilated carbon biomass in crop stubble in the PK treatment was also the highest (about 7%). The distribution proportion of assimilated carbon biomass in maize grain under the PK treatment was the lowest (30%). The C/N ratio in maize stem and leaf, cob, and crop stubble was the highest in PK treatment whereas it was the lowest under the 1.5NPKM treatment. The C/N ratio in stem and leaf, cob, and crop stubble in PK treatment was 121%, 105% and 120% higher than that in the 1.5NPKM treatment, respectively. In all fertilization treatments, the fixed carbon content in whole maize was the highest in NPKM treatment in above-ground parts of maize, and that was the highest in NPK balanced fertilization treatment in under-ground parts of maize. The fixed carbon content of maize in the above-ground part in NPKM treatment was about 7.2 t?hm-2 higher than that of the control treatment, NPK balanced fertilization treatment was 0.3 t?hm-2 higher than that of the control treatment for the under-ground part of maize. 【Conclusion】 The combined NPK fertilization and organic-inorganic fertilization significantly enhanced the carbon biomass of crop. These balanced fertilizations improved the distribution proportion of assimilated carbon in grain and cob, and then reduced the distribution proportion of assimilated carbon and the C/N ratio in stem and leaf, and crop stubble. These changes in distribution proportion of assimilated carbon and the C/N ratio by the balanced fertilization were helpful for the decomposition and transformation of returned straw and crop stubble into the soil. It indicates that balanced fertilization is a sustainable and environment-friendly management practice and has great significance for soil fertility and soil carbon sequestration.

    Effects of Spraying Chemical Regulator Dimethylpiperidinium Choride and Ethephon on Plant Ammonia Volatilization in Cotton of Xinjiang

    TANG Guang-mu,XU Wan-li,GE Chun-hui,MA Hai-gang,SUN Ning-chuan

    Scientia Agricultura Sinica. 2010, 43(23):  4862-4870 .  doi:10.3864/j.issn.0578-1752.2010.23.011
    Abstract ( 853 )   PDF (404KB) ( 953 )   Save
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    【Objective】The aims of the study were to determine the effects of chemical regulator of dimethylpiperidinium choride (DPC) and ethephon on plant ammonia volatilization in cotton of Xinjiang, and to reveal the mechanism on plant nitrogen nutrition.【Method】Ammonia volatilization from the cotton plants, indexes of soluble proteins (SP), activities of enzymes related to nitrogenous metabolism and stomatal characteristics were measured after the cotton plants sprayed with chemical regulators of DPC and ethephon in enclosure growth chamber.【Result】At the flowering and boll setting stages of cotton, average ammonia volatilization of cotton plants was reduced by 28.80% and 35.15% with the spraying of DPC at 1 g?L-1 and 1.5 g?L-1. There was a positive relationship between the ammonia volatilization and either the SP or area of stomata (P<0.05), and a negative correlation between ammonia volatilization and nitrate reductase (NR) activity, glutamine synthesis (GS) activity (P<0.05). The average ammonia volatilization of cotton plants with spraying of ethephon at 1.5 mL?L-1 and 2.5 mL?L-1 increased by 47.30% and 37.40% compared with no spraying control. A negative correlation was observed between ammonia volatilization and SP, NR activity, GS activity (P<0.05), whereas a positive relationship was observed between the ammonia volatilization and area of stomata (P<0.05). 【Conclusion】 Spraying of DPC reduced ammonia volatilization from cotton plants, which was mainly due to more photosynthetic transfer to reproductive organ from nutritional organs, reduced soluble protein content in leaves, enhanced NR and GS activities, and reduced the area of leaf stomata, which inhibited ammonia volatilization of cotton plants. Spraying of ethephon resulted in accelerating the plant senescence and the protein degradation, inhibiting the NR and GS activities, enlarging the area of leaf stomata, which promoted the ammonia volatilization of cotton plants.

    HORTICULTURE

    Transmission of n+1 Gametes and Obtaining of Two Bisomic Addition Lines of Flowering Chinese Cabbage-Chinese Kale

    CHEN Xue-ping,SHEN Er-qiao,ZHANG Cheng-he,LI Xiao-feng,XUAN Shu-xin,SHEN Shu-xing
    Scientia Agricultura Sinica. 2010, 43(23):  4871-4876 .  doi:10.3864/j.issn.0578-1752.2010.23.012
    Abstract ( 813 )   PDF (295KB) ( 758 )   Save
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    【Objective】 Transmission of the n+1 gametes of flowering Chinese cabbage-Chinese kale monosomic alien addition lines was studied in order to lay a basis for application of the gene localization and genetic improvement. 【Method】 The frequencies of n+1 gamete formation in different monosomic addition lines were assessed by a rate of PMCs with 10/10/11/11 segregation at anaphase Ⅱ. The transmission rates were determined by examining the chromosome number of plants derived from the populations of the different monosomic addition lines crossed with the flowering Chinese cabbage, respectively. The bisomic addition lines were selected from the selfing populations of the monosomic addition lines. 【Result】 The frequencies of n+1 male gamete formation in different monosomic addition lines were 36.85%-45.15%. The transmission frequencies of the monosomic addition lines varied from 7.14% to 14.81% for male gametes and from 19.07% to 36.51% for female gametes. There were no obvious associations of the n+1 gamete transmission rates with the n+1 gamete formation rates, chromosome size, pollen amount and pollen viability. Two different bisomic addition lines of the flowering Chinese cabbage-Chinese kale were identified from the selfing populations of the monosomic addition lines. 【Conclusion】 The extra chromosome of the flowering Chinese cabbage-Chinese kale monosomic addition lines can be transmitted by both female gametes and male gametes, but the transmission rates varied with the different monosomic addition lines, and the bisomic addition lines can be obtained from the selfing progeny of the monosomic addition lines.

    Screening for the Agronomic Traits Regulating Fruit Oleocellosis with the Specificity Between Rootstocks and Scions of ‘Hamlin’ Sweet Orange
    ZHENG Yong-qiang,DENG Lie,HE Shao-lan,ZHOU Zhi-qin,YI Shi-lai,ZHAO Xu-yang ,WANG Liang
    Scientia Agricultura Sinica. 2010, 43(23):  4877-4885 .  doi:10.3864/j.issn.0578-1752.2010.23.013
    Abstract ( 765 )   PDF (330KB) ( 795 )   Save
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    【Objective】 The main purpose of this paper was to screen agronomic traits of the specificity to fruit oleocellosis-tolerance between rootstocks and scions of ‘Hamlin’ sweet orange (Citrus sinensis L. cv. Hamlin), and to discuss the mechanism of oleocellosis-tolerance. 【Method】 Principal component analysis (PCA) and fuzzy clustering (FC) were used to evaluate the fruit oleocellosis-tolerance of ‘Hamlin’ sweet orange on 11 rootstocks based on their oleocellosis performance under the field conditions. 【Result】 The result of PCA indicated that the rates of oleocellosis (RO) were regulated by fruit maturity factor and oleocellsis sensitivity factor (S/R ratio and leaf Ca content), and the degree of oleocellosis (DO) were regulated by the flourishing decision factors (botanical characters) and the nutritional factors controlling DO (leaf N, Mg and Cu content). Whilst, plant nutrient physiology factors (leaf P, Zn and S content) participate in the RO and DO controlling. The ‘Hamlin’ sweet orange on 11 rootstocks used in this study could be divided into 4 clusters by FC based on their Oleocellosis Value of each PC (Fi). Among those ‘Hamlin’ sweet orange on 11 rootstocks, the oleocellosis tolerance of ‘Hamlin’ sweet orange on Rangpur Lime (Citrus limonia Osbeck, RL), Pomeroy trifoliate [P. trifoliate (L.), PM], Rubidoux trifoliate [P. trifoliate (L.), RB] and Volkamer lemon (C. volkameriana Pasqual, VL) were better, however, the causes of oleocellosis-tolerance were different; 【Conclusion】 It is an effective way by PCA and FC to screen for the agronomic traits regulating RO (fruit maturity factor and deocellsis sensitivity foctor) and DO (the flourishing decision factors and plant mutritional factors) and comprehensively evaluate the oleocellosis tolerance mechanism of Hamlin’ sweet orange by PCA and FC,which help to provide a theoretical basis for comprehensive control of citrus fruit oleocellosis.

    The Dwarfing Effect of Three Pear Dwarfing Intermediate Stocks on Grafting Trees
    JIANG Shu-ling,JIA Jing-xian,WANG Fei,OU Chun-qing,WANG Zhi-gang,XUAN Li-li,CHENG Fei-fei,MA Li
    Scientia Agricultura Sinica. 2010, 43(23):  4886-4892 .  doi:10.3864/j.issn.0578-1752.2010.23.014
    Abstract ( 829 )   PDF (335KB) ( 948 )   Save
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    【Objective】 Dwarfing effects and mineral elements content of the trees grafted on three dwarfing intermediate stocks S2, 82-5 and PDR54 were comparatively studied. That provided basis for the selection of inter-stocks in pear dwarfing culture. 【Method】 Different scions were grafted on S2, 82-5, and PDR54 (each has three different lengths) as inter-stock and P. betulaefolia Bge as rootstock. The growth and other indexes of grafting trees were measured. 【Result】 All of the S2, 82-5, and PDR54 had remarkable dwarfing effect. The dwarfing effect was enhanced when the intermediate stock was longer, but not with equal proportion. The dwarfing effect reached the maximum when the length of the inlermediate stock was 10 cm. The content of mineral elements in leaves of the trees grafted on the three intermediate stock was significantly different from the control. The content of N, Ca, Mg and Fe in the leaves grafted on S2 and 82-5 all showed an increasing trend and the content of Fe increased by 66.5% and 53.6%, respectively. But the content of mineral elements decreased in some degree on PDR54. 【Conclusion】 All of the S2, 82-5, and PDR54 had remarkable dwarfing effect, and the effect from strong to weak were PDR54>82-5> S2. The effect will reach the maximum when the length of the intermediate stock is 10 cm. As the dwarfing intermediate stock, S2 and 82-5 could promote the grafting tree to absorb mineral elements, especially for Fe, but PDR54 had the contrary function, so fertilizer application is needed for improvement.

    STORAGE·FRESH-KEEPING·PROCESSING
    Rapid Detection of Listeria monocytogenes in Food by Multiple PCR
    LIU Hai-quan,ZHAO Qiang,SUN Xiao-hong,Vivian C.H. WU,PAN Ying-jie,ZHAO Yong
    Scientia Agricultura Sinica. 2010, 43(23):  4893-4900 .  doi:10.3864/j.issn.0578-1752.2010.23.015
    Abstract ( 1007 )   PDF (655KB) ( 887 )   Save
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    【Objective】 A multiple polymerase chain reaction (PCR) system was developed to detect Listeria monocytogenes (LM),the more important food born pathogens, and applied to detect LM from food samples. 【Method】 Template DNA was obtained by thermolysis broth cultured bacteria and thermolysis colony. Primers were designed according to the 16S rRNA, inlAB, iap, hly genes. The concentration of primers and annealing temperature were examined and optimized. 【Result】 The PCR products were not detected in other Listeria spp, including L. innocua, L. seeligeri, L.welshimeri, L. ivanovii, L. grayi and in Vibrio parahemolyticus, indicating that this method was highly specific for L. monocytogenes. The detection limit of the PCR assay was 102 CFU/mL of pure cell culture. The PCR assay could detect no more than 0.4 CFU/g of L. monocytogenes in the contaminated pork. 【Conclusion】 The results show that the colony PCR method is better ,the method assay is highly sensitive, specific, rapid and accurate and can be used for rapid detection of L. monocytogenes in food.

    ANIMAL SCIENCE·RESOURCE INSECT
    Cloning, Imprinting Status and Tissue Expression Analysis of Porcine COPG2 and MEST Genes
    LI Shun,JIANG Cao-de,SHI Ping,DONG Ran-ran,WEI Jin,TIAN Jia-wei
    Scientia Agricultura Sinica. 2010, 43(23):  4901-4909 .  doi:10.3864/j.issn.0578-1752.2010.23.016
    Abstract ( 741 )   PDF (561KB) ( 602 )   Save
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    【Objective】 In order to find more novel candidate imprinted genes in pigs and assess their conservation among mammalian species and provide the basic molecular biology information and molecular markers for procine molecular genetics and breeding, comparative biology method was used to study porcine COPG2 and MEST genes. 【Method】 The porcine COPG2 and MEST genes from the one-month-old F1 hybrid pigs, between Rongchang and Landrace were cloned and sequenced, and then its molecular features were analyzed. Mapping of the porcine COPG2 and MEST genes to porcine chromosome were made with the IMpRH panel. Through the direct sequencing of the RT-PCR products, the imprinting status of both genes in 11 different tissues of one-month-old F1 heterozygotes were analyzed. The mRNA distribution of the porcine COPG2 and MEST genes in 11 different tissues (heart, stomach, skeletal muscle, kidney, lung, liver, small intestine, bladder, tongue, spleen and fat) were examined by real-time PCR. 【Result】 Two sequences with the full-length of 2 817 bp for COPG2 gene and 2 219 bp for MEST gene were cloned. COPG2 and MEST contain coding sequence of 2 616 bp and 981 bp, encoding proteins of 871 and 326 amino acid residues, respectively. By the IMpRH panel, porcine COPG2 and MEST genes were assigned to porcine chromosome 18, and closely linked with CL365941 with the LOD of 14.32 and 8.5, respectively. Imprinting analysis demonstrated that COPG2 was biallelically expressed in 11 tissues examined and MEST was paternally expressed in heart, stomach, skeletal muscle, kidney, lung, bladder, tongue and fat, while biallelically expressed in liver, small intestine and spleen. Real-time PCR results showed that the expression level of porcine COPG2 and MEST were significantly different among tissues of one-month-old pig (P<0.01). Both the COPG2 and MEST genes showed the highest expression levels in the kidney than all of the other tissues. 【Conclusion】 The sequence of COPG2 is conservative, but the imprinting status is not conservative among mammalian species. For MEST, both the sequence and imprinting status are conservative, and MEST has tissue specific expression in pigs. In addition, the results of mapping and imprinting status of MEST and COPG2 confirm the novel imprinted domain on porcine chromosome 18.
    Study on Lactation Curve Models of Chinese Holstein for the Second Parity

    LUO Qing-yao,XIONG Ben-hai,MA Yi,PANG Zhi-hong1,DENG Wen
    Scientia Agricultura Sinica. 2010, 43(23):  4910-4916 .  doi:10.3864/j.issn.0578-1752.2010.23.017
    Abstract ( 800 )   PDF (266KB) ( 926 )   Save
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    【Objective】 An experiment was made in order to precisely predict nutrient requirements of individual dairy cattle and study lactating characteristics of milk compositions. 【Method】 Two hundred and eighty-nine dairy cows were divided into 7 groups from 6 000 kg to 10 000 kg with an interval of 1 000 kg according to 305-day milk yield in the second parity. The adjusted month-milk-yields were fitted using 3 equations (Wood, Gompertz and Dijkstra equations). Twenty-one sets of lactation curve models for different milk yield ranges were obtained by SAS nonlinear parameter estimation and mean square error (MSE) analysis and lactation feature indices of each yield range including initial yield (y0), time to peak yield (tm), peak yield (ym) and relative rate of decline at the point halfway between peak yield and the end of lactation (r(th)) were revealed by model parameters. 【Result】 Analyses of the model parameters and feature indices showed that the above three mathematic equations are all able to describe lactation characteristics of Chinese Holstein dairy cows among different milk yield ranges for the second parity well,but their characteristics were different: a,b and c from Wood and Gompertz model changed regularly with the average yield (Yavg) of yield ranges (except for model 14 ); Y0 estimated by Gompertz was the best by means of regularity while Y0 of Wood had limitations, that of Dijkstra was different widely and could not reflect practical situations. Results of tm estimated by Wood was better than that of the other models which the variation was big in the lowest and highest yield ranges. Values of ym and r(th) of 3 models were highly consistent. 【Conclusion】 Above lactation curve models for different lactation ranges could provide reference for the accurate prediction of nutrient requirements and precise feeding for dairy cattle.

    Detection of Genetic Co-Adaptability of Chinese Local Sheep Breeds and Comparison with Their Closely Related Species-Goat
    SUN Wei,CHANG Hong,YANG Zhang-ping,MA Yue-hui,GUAN Wei-jun,CHU Ming-xing,TSUNODA Ken-ji,WU Wen-zhong,CHEN Ling,QIAN Jian-gong
    Scientia Agricultura Sinica. 2010, 43(23):  4917-4927 .  doi:10.3864/j.issn.0578-1752.2010.23.018
    Abstract ( 795 )   PDF (344KB) ( 504 )   Save
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    【Objective】The objective of this study was to find the proper model of combined loci in analysis of genetic co-adaptability, and add the data of genetic co-adaptability theory on evolution mechanism difference of genetic co-adaptability among breeds or between closely related species-goat.【Method】Tan sheep, small-tailed Han sheep, Hu sheep, Tong sheep and Wadi sheep were regarded as the research objects and their closely related species-goat was served as the reference object, and 9 structural loci with different polymorphism were selected. 【Result】 The dominant-dominant model was not proper to be used in genetic co-adaptability analysis. The co-dominant-dominant model the co-dominant-co-dominant model could be used in genetic co-adaptability analysis. The principles of classic neutral gene genetic disequilibrium could explain most genetic disequilibrium between loci, but the principles could not fit for Tf locus with too many rare alleles, because it could not provide a rational explanation or the explanation was inconsistent. The differences in the coefficients of genetic co-adaptability, genetic disequilibrium and link disequilibrium between sheep and goat (among species) and breeds (within groups) decided by different loci combinations. 【Conclusion】 Genetic co-adaptability do not exist in the loci combination of dominant-dominant, but it may exist in the loci combination of co-dominant-dominant and co-dominant-co-dominant. Due to different origins, there is a large difference in genetic co-adaptability between sheep and goat, while the different breeds of sheep species with the same origin have a consistent tendency in genetic co-adaptability. This is the first time, that the regression equations of coefficients of genetic co-adaptability and genetic disequilibrium in different models were obtained, which will be helpful for research on function mechanism and calculation of genetic co-adaptability.

    VETERINARY SCIENCE

    Cloning and Expression of Yak Copper, Zinc-Superoxide Dismutase in E.coli

    XU Ya-ou,YUAN Zhong,MAO De-cai,MAO Liang,ZHENG Yu-cai
    Scientia Agricultura Sinica. 2010, 43(23):  4928-4935 .  doi:10.3864/j.issn.0578-1752.2010.23.019
    Abstract ( 777 )   PDF (807KB) ( 623 )   Save
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    【Objective】 Due to the medical superoxide dismutase (SOD) source is restricted from animals and plants, establishment of the prokaryotic expressing system of yak Cu, Zn-SODpET22b(+)-E. coli BI21(DE3) by genetic engineering method is a basis for recombinant SOD protein of clinical injection. 【Method】 Yak Cu, Zn-SOD gene was amplified using reverse transcription-polymerase chain reaction (RT-PCR). The PCR product was inserted into the vector pET22b(+) to construct plasmid Cu, Zn-SOD/ pET22b(+), then the plasmid expressed in E. coli BL21 (DE3) cell that induced by IPTG. The expression product and it's activity were tested by the method of SDS-PAGE, native PAGE (enzyme active stain) electrophoresis and pyrogallol (1,2,3-trihydroxybenzene) self oxidation. The level of expression protein was determined by Brad Ford. 【Result】 The length of ORF of yak Cu, Zn-SOD was 456 bp encoding 152 amino acids peptides. The nucleotide sequence and amino acids sequence of Cu, Zn-SOD similarities between yak and bovine were 99.6% and 98.7%, respectively. The activity ratio of the protein crude extract of recombinant Cu, Zn-SOD was 35U?mg-1. The concentration of the recombinant Cu, Zn-SOD is 0.2772 (mg?mL-1). 【Conclusion】 The prokaryotic expression vector for yak Cu, Zn-SOD/pET22b(+) was constructed successfully and it expresses in Escherichia coli stably and highly. The recombinant product was obtained and the product has higher biological activity.

    Polymorphism of LYZ Gene and Its Association with Mastitis Trait in Chinese Holstein

    CHEN Ren-jin,YANG Zhang-ping,MAO Yong-jiang,CHEN Ying,CHANG Ling-ling,WU Hai-tao,JI De-jun,LI Yun-long,ZHANG Ya-qin
    Scientia Agricultura Sinica. 2010, 43(23):  4936-4941 .  doi:10.3864/j.issn.0578-1752.2010.23.020
    Abstract ( 936 )   PDF (425KB) ( 650 )   Save
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    【Objective】 The polymorphism of coding region of LYZ gene and its correlation with somatic cell score (SCS) and 305 d milk yield in Chinese Holstein were analyzed for the purpose of providing molecular markers in the marker-assisted selections (MAS) to accelerate the disease-resistant breeding progress in Chinese Holstein .【Method】 The polymorphism of LYZ gene was detected by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique in 610 Chinese Holstein cattle from 30 bull families. The associations between polymorphic sites of LYZ gene and SCS and 305 d milk yield were analyzed by the least square mean analysis. 【Result】 The 115(T>G)mutation site was found in the exon1, and the mutation resulted in an amino acid change of Arg→Leu, for the polymorphic site, three genotypes (TT, TG and GG) were found in 610 Chinese Holstein by PCR-SSCP,and the frequency of TT, TG and GG genotypes was 0.270, 0.508 and 0.222, respectively. Chi-square tested showed Chinese Holstein was not in Hardy-Weinberg equilibrium at the site. Least square mean of SCS for GG genotype was highly and significantly lower than that for TT (P<0.01), and significantly lower than TG genotype (P<0.05). Least square mean of 305 d milk yield for GG genotype was greatly and significantly higher than that for TT (P<0.01), and significantly higher than TG genotype (P<0.05).【Conclusion】 GG genotype at 115(T>G)site had a great genetic effect on SCS and 305 d milk yield in Chinese Holstein, which can be used as a candidate marker for mastitis resistance selection in dairy cattle.

    AGRICULTURAL ECONOMY
    Design of Products for Rice Agro-Meteorological Index Insurance: A Case in Zhejiang Province
    WU Li-hong,LOU Wei-ping ,YAO Yi-ping,MAO Yu-ding,SU Gao-Li
    Scientia Agricultura Sinica. 2010, 43(23):  4942-4950 .  doi:10.3864/j.issn.0578-1752.2010.23.021
    Abstract ( 858 )   PDF (488KB) ( 1575 )   Save
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    【Objective】 Products for agro-meteorological index of rice crop insurance were designed to provide technical support for sustainable development of policy-guided agricultural insurance. 【Method】 By means of the correlations between the reduction of rice production and weather factors as well as atmosphere circulation index, a model of reduction of rice output was established. Using meteorological data, the probability of risk in rice reduction at different levels was calculated through beta, and the rates and premiums of insurance were determined. Synthesizing the advantages of products and weather index insurance, the insurance products would be designed. 【Result】 Calculating the risk rates of rice yield reduction, the deducible amount was 7.5% in the 18 coastal counties of Taizhou, Zhoushan and Ningbo, 5.0% in 16 counties such as Lanxi and 2.5% in 34 counties in Jiaxing. According to the calculus of probability and the model of rice yield loss, the plan and the contracts of rice agro-meteorological index insurance products were designed. 【Conclusion】 Agro-meteorological index crop insurance is an innovation meeting the requirements of insurance operations in China. Using the techniques of rice production forecast, determining the damages by means of real meteorological data, the shortages such as low efficiency, high costs and low accuracy would be cut greatly in agricultural insurance operations. It is good to reduce the anti-selection and promote the constant development of agriculture insurance.

    The Short-Term Market Price Transmission Mechanism of Egg Industry Chain in China
    LI Zhe-min,XU Shi-wei,DONG Xiao-xia,LI Gan-qiong,LIU Hong,WANG Yu-ting
    Scientia Agricultura Sinica. 2010, 43(23):  4951-4962 .  doi:10.3864/j.issn.0578-1752.2010.23.022
    Abstract ( 848 )   PDF (436KB) ( 819 )   Save
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    【Objective】 Price transmission in egg industry chain involves the steps of production, circulation and consumption. In order to early warn and reduce the short-term market price fluctuations of egg products, the transmission relations and transmission mechanism between the prices were analyzed at the angle of the whole industry chain which is composed of the upstream, midstream and downstream. 【Method】 It was the first time for the study on the short-term market price transmission mechanism in egg industry chain in China. The price transmissions of egg industry chain were analyzed with co-integration test and vector error correction model (VEC). What’s more, the transmission mechanism between prices was determined by variance decomposition and Granger-causality test model. 【Result】 The co-integration test results showed that the co-integration relationship between prices existed in the egg industry chain. Changes of 1% in DYCJJG, PHSL and PFJG would cause the changes of 0.23%, -0.09% and 1.04% in LSGJ, respectively. The egg price fluctuation in short term was restricted by the long-term equilibrium relationship of the price system in egg industry. With a negative error correction coefficient, it was consistent with reverse correction mechanism, meanwhile, the intensity of correction was up to 17%. Accompanied by a certain period of delay, the transmission between the prices in egg industry was not fast smoothly. There was 1 month lag when downstream LSJG transmitted to upstream PHSL, PHSL transmitted to midstream PFJG, upstream DYCJJG transmitted to PHSL, LSJG transmitted to DYCJJG, DYCJJG transmitted to PFJG and LSJG transmitted to PFJG. 【Conclusion】 There was a long-term equilibrium relationship between the prices in egg industry, which restricted the price fluctuation in short term, in this way, deviation between the prices would be reduced automatically and an equilibrium of prices emerged. The changes in the price of upstream products would cause the changes in the prices of midstream and downstream products. That the price transmission in egg industry was not fast smoothly means that, some measures made by some departments of the government are needed in order to ensure the smooth of market price transmission in egg industry chain in China, improve the efficiency of price conduction.

    RESEARCH NOTES
    Research on Establishment of a Highly Frequent and Efficient Regeneration System of Sorghum bicolor
    LIU Xuan-yu,LIU Shu-jun,SONG Song-quan
    Scientia Agricultura Sinica. 2010, 43(23):  4963-4969 .  doi:10.3864/j.issn.0578-1752.2010.23.023
    Abstract ( 801 )   PDF (366KB) ( 792 )   Save
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    【Objective】 The objective of this research was to establish a highly frequent and efficient regeneration system of sweet sorghum (Sorghum bicolor L. Moench), a kind of energy plants, so as to make preparation for genetic transformation.【Method】 The shoot apical meristems of sweet sorghum Keller were used as explants to investigate the effect of seedling age, phytohormone combinations and their ratios on the direct induction process of multiple shoots. Whether this regeneration pathway is less genotype-dependent in sweet sorghum, and whether the optimal culture method obtained above could be extended to other two genotypes, M-81E and Italian, were studied. 【Result】 It was easier to obtain a high meristem enlargement percentage using the shoot apical meristem from 3-day-old sterile seedlings as the explants. The optimal phytohormone combinations for multiple shoot induction of sweet sorghum were 4.0 mg?L-1 6-benzylaminopurine + 0.5 mg?L-1 2,4-dichlorophenoxyacetic acid + 0.5 mg?L-1 thidiazuron, in which 91% of multiple shoot induction could be achieved. Naphthaleneacetic acid at 0.5 mg?L-1 markedly increased rooting rate of multiple shoots. One explant with shoot meristem could be induced to produce above 100 multiple shoots, and finally 30–40 regenerated plants were produced through a directly-induced multiple shoot pathway. M-81E and Italian had a similar induction percentage and efficiency of multiple shoots as Keller. 【Conclusion】 A highly frequent and efficient regeneration system of sweet sorghum was successfully established, which has a sustainable explant supply, less genotype-dependence and good genetic stability.

    Degradation Dynamics of Cry1Ab Insecticidal Protein Within Transgenic Bacillus thuringiensis Corn Root Debris and Rhizosphere Soil in Field

    XING Zhen-juan,WANG Zhen-ying,HE Kang-lai,BAI Shu-xiong
    Scientia Agricultura Sinica. 2010, 43(23):  4970-4976 .  doi:10.3864/j.issn.0578-1752.2010.23.024
    Abstract ( 752 )   PDF (309KB) ( 759 )   Save
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    【Objective】 The field degradation dynamics of Cry1Ab insecticidal protein in transgenic Bacillus thuringiensis corn in the root debris and rhizosphere soil of corn of events MON810 and Bt11 at harvest stage were investigated and compared. 【Method】 The levels of Cry1Ab protein expression in root debris and rhizosphere soil of the two transgenic Bt corns of events MON810 and Bt11were quantified by using enzyme-linked immunosorbent essay (ELISA). 【Result】 It was showed that the Cry1Ab toxin in Bt corn root debris and rhizosphere soil were gradually degraded. The content of Cry1Ab insecticidal protein in corn root debris of MON810 was higher than that of Bt11, the degradation speed was slower compared with that of Bt11. The Cry1Ab insecticidal protein in root debris could not degrade completely in 8 months after harvest. No Cry1Ab insecticidal protein was detected in root debris of Bt11 in 7 months after harvest. Degradation of Cry1Ab insecticidal protein in rhizosphere soil of event MON810 was slower than that of event Bt11, no Cry1Ab insecticidal protein was detected in the rhizosphere soil of events MON810 and Bt11 in 8 months and 7 months after harvest, respectively. 【Conclusion】 The Cry1Ab insecticidal protein could not degrade completely, and some residues still remain in root debris and rhizosphere soil of events MON810 and Bt11 in the emerging stage of the spring crops in following year in field where the MON810 and Bt11 were planted.

    Spatial Variability of Soil Enzyme Activity in Pear Orchard Under Clean and Sod Cultivation Models
    XU Ling-fei,HAN Qing-fang,WU Zhong-ying,WEI Peng,YANG Bao-ping,NIE Jun-feng
    Scientia Agricultura Sinica. 2010, 43(23):  4977-4982 .  doi:10.3864/j.issn.0578-1752.2010.23.025
    Abstract ( 726 )   PDF (272KB) ( 871 )   Save
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    【Objective】 The objective of this study was to investigate spatial variabilities of soil catalase, invertase, and alkaline phosphatase activities of pear orchard under clean and sod cultivation management systems. 【Method】 With the soil of pear (cv. Dangshansu on P. betulaefolia Bge. rootstock) orchard under clean and sod cultivation models as test materials, the experiment was conducted to evaluate spatial variability of soil catalase, invertase, and alkaline phosphatase activities in between rows and different soil layers (0-60 cm). 【Result】 Each enzyme activity showed difference in between rows of the same soil layer in pear orchard with clean and sod cultivation management systems. Variability of soil enzyme activity was found in the horizontal direction. Soil enzyme activities were also different in vertical soil layers under two culture models. Invertase activity in 0-20 cm soil layer was higher than those in 20-40 and 40-60 cm soil layers in between rows. Catalase activities in 0-20 and 20- 40 cm of soil layers were higher than that in 40-60 cm soil layer between rows. Alkaline phosphatase activity in 20-40 cm soil layer was lower than those in 0-20 and 40-60 cm soil layers in between rows. The activities of three enzymes of sod cover were higher than the performance of clean cultivation in the three soil layers, except that invertase activity of sod cover was lower as compared to that of clean cultivation in 40-60 cm soil layer. Sod cultivation model significantly improved soil alkaline phosphatase, invertase, and catalase activities of pear orchard, and the three enzyme activities increased by 22.94%, 4.75%, and 21.12% compared to clean cultivation, respectively. 【Conclusion】 In clean and sod cultivation models, the three enzyme activities exhibited spatial variabilities, and sod cover increased these enzyme activities than clean cultivation.