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    28 June 2006, Volume 13 Issue 2 Previous Issue    Next Issue

    Research Paper
    Short Communication
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    Research Paper
    Transgenic Expression of the Recombinant Phytase in Rice (Oryza sativa)
    LIU Qiao-quan,﹟, LI Qian-feng,﹟, JIANG Li, ZHANG Da-jiang, WANG Hong-mei, GU Ming-hong, YAO Quan-hong
    2006, 13(2): 79-84 . 
    Abstract ( )   PDF (173KB) ( )  
    In most of the cereal crop, phytic acid is the main storage form of phosphorus, which can decrease the bioavailability of phosphate. Transgenic expression of phytase is regarded as an efficient way to release phosphate from phytate in transgenic plants. In this study, a plant expression vector, containing the recombinant phytase gene driven by the maize ubiquitin (Ubi) promoter was constructed and introduced into an elite rice variety via Agrobacterium-mediated transformation. During the experiment, a total of 15 independent transgenic rice lines were regenerated. The results of PCR and Southern blot indicated that the target gene was integrated into the genome of transgenic rice plants. Moreover, the RT-PCR analysis of total RNAs extracted from the immature seeds of several transgenic lines showed that the recombinant phytase gene could be normally expressed. The inorganic phosphorus content, both in the mature seeds and the leaf was significantly higher in the transgenic plants than in the untransformed wild type.
    Genetic Diversity of Seed Storage Proteins in Different Ecotype Varieties of japonica Rice and Its Application
    JIN Wei-dong , LI Na , HONG De-lin
    2006, 13(2): 85-92 . 
    Abstract ( )   PDF (130KB) ( )  
    One hundred and fifteen varieties (including cultivars and lines) with different ecotypes in japonica rice (Oryza sativa L.) were analyzed for endosperm storage proteins by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to estimate their genetic diversity for the purpose of genetic improving and variety identification. Nineteen types of profile were identified according to 1) presence/absence of 65 kDa bands, 2) staining intensity of 70, 60, 57, 37-39, 22-23, 13 and 10 kDa bands, 3) migration velocity of 35 kDa (α-4) and 4) band number at 57 kDa location. An unweighted-pair group average method with arithmetic mean (UPGMA) dendrogram based on the cluster analysis of genetic similarity of the protein bands showed a small genetic variation among the tested materials, with the similarity coefficients varying between 0.75 and 1.00. Three distinct groups were identified from the cluster analysis of the rice varieties studied at the similarity coefficient level of 0.894. The first group included eight varieties with high amylose content, the second group contained fifteen varieties with high protein content, and the third group had the remaining ninety-two varieties, which accounted for 80% of the total materials. Clear relationship between ecotypes distinguished by maturity and groups revealed by cluster analysis was not found in this study. Only the group of high amylose linked with medium-maturity medium japonica ecotype. The bands of 70 kDa and 65 kDa can be used as protein markers to identify F1 seed purity of japonica hybrid rice Liuyanyou 422.
    QTL Mapping of Low Temperature on Germination rate of Rice
    CHEN Liang, LOU Qiao-jun, SUN Zong-xiu, XING Yong-zhong, YU Xin-qiao, LUO Li-jun,
    2006, 13(2): 93-98 . 
    Abstract ( )   PDF (82KB) ( )  
    To investigate the low temperature on germination capacity (LTG) a double haploid rice (DH) population with 198 lines derived from anther culture of F1 hybrid with indica line Zhenshan 97B and a perennial japonica line AAV002863 was used to construct a linkage map with 140 SSR markers. The germination rate in Zhenshan 97B and AAV002863 was 79.7% and 30.1%, while in DH population it ranged from 0 to 100% at 15℃ after 6 days. Quantitative trait loci (QTLs) controlling low temperature germinability were identified on chromosomes 3 and 10. The percentage of observed phenotypic variance attributed to qLTG-3 and qLTG-10 was 12.6% and 12.9%, respectively. Allele from Zhenshan 97B increased the LTG at qLTG-3 region, while allele from AAV002863 increased the LTG at qLTG-10 region. One pair of epistatic interaction was detected between loci on chromosomes 3 and 10. The main-effect of QTL on chromosome 10 was also involved in epistatic interaction.
    Developmental Analysis of Genetic Behavior of Brown Rice Width in indica-japonica Hybrids
    ZHANG Xiao-ming , SHI Chun-hai , YE Shen-hai , QI Yong-bin
    2006, 13(2): 99-105 . 
    Abstract ( )   PDF (68KB) ( )  
    The developmental genetic behaviors of brown rice width (BRW) have been studied in indica-japonica hybrid rice (Oryza sativa L.), in which seven indica male sterile lines and five japonica restorer lines were applied, by using the developmental genetic models and corresponding statistical approaches for quantitative traits of triploid in cereal crops. The BRW of indica-japonica hybrid rice was co-determined by gene expression of triploid endosperm, cytoplasm, diploid maternal plant and their genotype × environmental interaction effects. Unconditional analysis showed that the endosperm additive and maternal additive effects were predominant for the development of BRW from early- to late-stage of the grain development, but the endosperm dominant effect together with maternal effect and cytoplasmic effect became the major factor determing the BRW at the ripening stage. Moreover, conditional analysis found that there were new onset and offset of gene expression at different developmental stages of BRW in indica-japonica hybrid rice. Maternal and cytoplasm general heritabilities and their interaction heritabilities were more important compared to other components of heritability for BRW at all the five developmental stages.
    Development and Substance Accumulation of Caryopsis in Transgenic Rice with Antisense Wx Gene
    CHEN Gang, WANG Zhong, LIU Qiao-quan, XIONG Fei, GU Yun-jie, GU Guo-jun
    2006, 13(2): 106-112 . 
    Abstract ( )   PDF (82KB) ( )  
    The development and substance accumulation of rice caryopsis were studied by using the transgenic japonica and indica rice with antisense Wx gene. The weight of caryopses in transgenic rice was lower than that in non-transgenic one, and the reduction in weight was significantly correlated to the reduction in amylose content. In caryopsis of transgenic rice, the number of endosperm cells was less than that in caryopsis of non-transgenic one, but the proliferation speed was considerably higher during the first six days after flowering (DAF). During the first nine DAF, the soluble sugar content of transgenic rice caryopsis was less than that of the non-transgenic one, but the situation was reverse after nine DAF. Moreover, the total starch content also declined with the decrease in amylose content of transgenic rice caryopsis, while the amylopectin content increased accordingly. Therefore, the composition of starch in caryopsis also changed, but it did not affect the accumulation of protein in transgenic rice caryopsis.
    Responses of Photosynthetic Functions to Low Temperature in Flag Leaves of Rice Genotypes at the Milky Stage
    WANG Jing, ZHANG Cheng-jun, CHEN Guo-xiang, WANG Ping, SHI Da-wei, LU Chuan-gen
    2006, 13(2): 113-119 . 
    Abstract ( )   PDF (66KB) ( )  
    To examine the chilling resistance of a newly developed super hybrid rice (Oryza sativa) Liangyou 122 at the different temperatures, an experiment was conducted to investigate the photosynthetic pigments contents, changes in fatty acids content of thylakoid membrane and the activities of several anti-oxidative enzymes at milky stage with traditional hybrid rice Shanyou 63 as control, by growing rice under the 25/15℃ and 25/20℃ day/night temperature. The results showed that the malondialdehyde(MDA) content and superoxide anion(O2-) were increased remarkably, while the activities of superoxide dismutase(SOD) and catalase(CAT) were obviously decreased with the duration of low temperature treatment. Moreover, the change enhanced with the increased difference between day and night temperatures. Meanwhile, the index of unsaturated fatty acid (IUFA) of both varieties also increased. As a result, the photosynthetic rate and the chlorophyll content were decreased considerably, while at beginning the carotenoids content increased and then decreased. Of all the parameters investigated, the variation range in Liangyou 122 was less than that in Shanyou 63, but the values of the former were more than the latter, which means that Liangyou 122 may be more resistant to chilling temperature at the milky stage.
    Effects of Free-air CO2 Enrichment on Root Characteristics and C:N Ratio of Rice at the Heading Stage
    CHEN Gai-ping, CHENG Lei, ZHU Jian-guo, PANG Jing, XIE Zu-bin, ZENG Qing
    2006, 13(2): 120-124 . 
    Abstract ( )   PDF (38KB) ( )  
    A hydroponics experiment was conducted to investigate the rice root growth in FACE (free-air carbon dioxide enrichment). The root biomass, root volume, ratio of root/shoot, number of adventitious roots and root diameter significantly increased under FACE conditions, while the CO2 enrichment decreased the N concentration in rice roots without any change in the C content, leading to an increase in root C:N ratio. Moreover, the elevated CO2 resulted in a remarkable decrease of root activity, expressed as per unit root dry weight, which might be responsible for decreased N concentration in roots.
    Simulation and Validation of Rice Potential Growth Process in Zhejiang
    Province of China by Utilizing WOFOST Model
    XIE Wen-xia, YAN Li-jiao, WANG Guang-huo
    2006, 13(2): 125-130 . 
    Abstract ( )   PDF (64KB) ( )  
    A crop growth model of WOFOST was calibrated and validated through rice field experiments from 2001 to 2004 in Jinhua
    and Hangzhou, Zhejiang Province. For late rice variety Xiushui 11 and hybrid Xieyou 46, the model was calibrated to obtain parameter
    values using the experimental data of years 2001 and 2002, then the parameters were validated by the data obtained during 2003.
    For single hybrid rice Liangyoupeijiu, the data recorded in 2004 and 2003 were used for calibration and validation, respectively. The
    main focus of the study was as follows: the WOFOST model is good in simulating rice potential growth in Zhejiang and can be used to
    analyze the process of rice growth and yield potential. The potential yield obtained from the WOFOST model was about 8100 kg/ ha
    for late rice and 9300 kg/ ha for single rice. The current average yield in Jinhua is only about 78% (late rice) and 70% (single rice) of
    their potential yield. The results of the simulation also showed that the current practice of management at the middle and late growth
    stages of rice should be reexamined and improved to reach optimal rice growth.
    Effect of Establishment Methods and Weed Management Practices on Some Growth Attributes of Rice
    Mohammad Safdar BALOCH,*, Inayat Ullah AWAN, Gul HASSAN, Abdul Aziz KHAKWANI
    2006, 13(2): 131-140 . 
    Abstract ( )   PDF (66KB) ( )  
    Studies were carried out for two years to evaluate the effect of methods of sowing and weed control practices on the productivity of transplanted and direct wet-seeded rice in Dera Ismail Khan, NWFP, Pakistan. The experiment was laid out in a randomized complete block design with a split plot arrangement. The planting techniques viz. transplanting and direct seeding were maintained in main plots while weed control practices included the use of granular herbicide Sunstar 15WG (ethoxy sulfuron), Machete 60EC (butachlor), conventional hand weeding, and the weedy check (control) were assigned to the sub-plots. Data were recorded on weed parameters like weed density and dry weed biomass 60 and 90 days after sowing (DAS); agronomic parameters including plant population, number of panicles and paddy yield and physiological parameters like leaf area index and net assimilation rate 45 and 90 DAS. The planting methods and weed management significantly influenced most of the parameters studied. The data revealed that the paddy yield and its components were significantly higher in the transplanted method than that in direct-seeded method, while the weed density and biomass were lower in the transplanted plots than the direct-seeded plots. Among weed management tools, the maximum paddy yield was obtained in hand weeding, closely followed by herbicide application Machete 60EC during both cropping seasons.
    Characterization and Identification of Two Opportunistic Human Bacterial Pathogens in Rice
    LUO Yuan-chan, XIE Guan-lin, ZHANG Li-xin, AN Gilmyong, FANG Yuan, LUO Jin-yan, HAO Xiao-juan, ZHAO Si-feng
    2006, 13(2): 141-145 . 
    Abstract ( )   PDF (49KB) ( )  
    Burkholderia cepacia (Bc) and Pseudomonas aeruginosa (Pa) are both biocontrol agents in agriculture and opportunistic human pathogens in hospitals. Effective management and utilization practice is needed to understand their characteristics and distribution in rice. During the last decade, the two opportunistic human pathogens were detected in 631 samples of rice seed and 117 samples of rice plant in plain, highland and mountainous rice growing areas of China. Bc and Pa were primarily differentiated by common bacteriological characteristics and pathogenic tests and then identified into species by Biolog and FAME tests. However, the genotypes of Bc still could not be distinguished. It has been noted that the Bc and Pa mainly existed in rice root with the highest distribution frequency in plain areas ( 6.1% and 16.1%) and lowest in the mountainous areas (1.0% and 7.8%).
    Short Communication
    Repellent Activity of Extracts of Wild Rice Species against Panonychus citri and Aphis citricola in Associated with Esterase Isoenzyme in Insests
    WAN Shu-qing, LIU Xiang-fa, FENG Guo-zhong, PAN Da-jian
    2006, 13(2): 146-148 . 
    Abstract ( )   PDF (47KB) ( )  
    Six species of wild rice with different ecophenotypes including Oryza grandiglumis (E6-1, E6-3 / 6-4), O. minuta (E13-9, E13-13), O. officinalis (E15-8, E15-13), O. punctata (E16-1, E16-3, E16-13), O. granulata (E7-4), and O. latifolia (101392, E9-1, E9-10) were extracted with methnol and the repellent activity of the extracts against the two insects Aphis citricola and Panonychus citri were studied. The extracts of O. officinalis E15-8 showed higher repellent rate to the two insects than those of the other species. The repellent rates of the extracts of E15-8 to P. citri and A. citricola were 83.26% and 87.86% at 5×104 µg/mL in 24 h and 87.95% and 82.43% in 48 h, respectively. The extracts of O. officinalis E15-8 had the effect of inhibition to the esterase of the two insects.