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    研究报告
    The Finds and Morphological Study of Carbonized Rice in the Neolithic Site at Jiahu in Wuyang County, Henan Provinc
    Chen Baozhang,Wang Xiangkun,Zhang Juzhong
    1995, 9(3): 129-134 . 
    Abstract ( )   PDF (456KB) ( )  
    Through diffusing-sieving, a lot of carbonized caryopses of rice were found in the samples which were collected from the Neolithic site at Jiahu in Wuyang County, Henan Province (33°37' N, 133°40'E). Morphological study indicates that the major part of ancient rice at Jiahu is cultivated keng (japonica) or approaching keng(L/W is 1. 88-2. 48), and the minority is cultivated hsien (indica) or approaching hsien (L/W is 2. 50-3. 00). The range of Calibrated radiocarbon ages of the cultured ruins in this site is 8942~7868 a BP. This find of Jiahu carbonized caryopses of rice is not only the earliest evidence of cultivated rice in Yellow Rivers and Huaihe Rivers, but also one of the earliest data in the world by now. It is no doubt of great significance for study of origin of rice in China even in the world. Based on analysing of ancient cultural ecology and agricultural origin mechanism, the authors also discuss why Jiahu ancestors began planting rice earlier, and deduce that the Huaihe Rivers may be one of the cradle centers of Chinese cultivated rice owing to this area had edge effects of ancient climatic and ancient cultural transit tion.
    RFLP-based Analysis of the Origin and differentiation of Oryza sativa L.
    Zhuang Jieyun,Qian Huirong,Lin Hongxuan,Lu Jun,Cheng Shihua,Ying Cunshan,Luo Lijun,Zhu Xudong,Dong Fenggao,Min Shaokai,Sun Zongxiu,Zheng Kangle
    1995, 9(3): 135-140 . 
    Abstract ( )   PDF (327KB) ( )  
    RFLPs among 14 accessions of O. rufipogon from five provinces of China and 19 Asian cultivated varieties from 8 countries were assayed with 20 DNA probes. Seventeen probes distributed on 10 chromosomes detected polymorphisms with 67 polymorphic fragments in combination with single enzyme. Cluster analysis revealed clear classification of O. rufipogon, indica and japonica. Genetic distances between the three groups were similar, indicating that indica and japonica might be differentiated from ancient Asian wild rice almost simultaneously. In addition, none of the accessions of O. rufipogon showed obvious tendency towards indica or japonica.
    Characterization of Dwarf Isogenic Lines of indica Rice
    Zhu Lihong,Xie Chongqing,Wang Haoxi,Teng Youren,Xu Qin,Dai Jian
    1995, 9(3): 141-148 . 
    Abstract ( )   PDF (574KB) ( )  
    Two sets of dwarf isogenic lines of indica rice have been developed by crossing eleven dwarf and semidwarf varieties or lines respectively with two tall cultivars, Mianhuatiao and Nanjing 6, and backcrossing forfive generations to the tall cultivars. Pleiotropical effects of dwarf genes on twenty two kinds of characters pertaining to plant height, leaf pattern, and yielding capabilities were studied. Results indicated that multiple effects of dwarf genes were apparent on such traits as plant height, length of four internodes above ground, length of panicle,length and width of upper three leaves, leaf angle of boot leaf and second leaf counting from the top. Differenceswere observed between sd-1 and nonallelic dwarf genes. Most charalters between isogenic lines and correspondingvarieties or lines were found to be significantly different also. The tentative cause of variation not due topleiotropism were discussed.
    Genetic Effect Analysis on Pigment Content in Pericarp of Black Rice Grain
    Zhang Mingwei,Peng Zhongming,Xu Yunqi
    1995, 9(3): 149-155 . 
    Abstract ( )   PDF (427KB) ( )  
    Experiments on genetic effect of pigment content in pericarp of black rice grain were conducted with 6 combinations from 3 black pericarp rice varieties with different pigment contents and one non-pigmental variety. Genetic studies indicated that the means of pigment content in F2 generations of 6 crosses were usually within the range of mid-parent, the frequencies of pigment content in pericarp was controlled by quantitative inheritance. On the other hand, a 7 ×7 diallel cross of 6 black pericarp rice cultivars and 1 non-pigmental rice cultivar was made, genetic analysis was conducted by Hayman's model. The results were as follows: the inheritance of pigment content could be described by an additive-dominance model, the alleles for high pigment content were dominant to those for low pigment content, the deep black pericarp was expressed as dominant trait over light black one, and black pericarp was dominant to non-pigmental one, in other words, least number of dominant gene was 2, and the average dominance was within the range of incomplete dominance, the action direction of all dominant locies was consistent, and the heritabilities in broad sence and narrow one were high. In accordance with the results, the problems related to the breeding of rice varieties with deep black pericarp or high pigment content in pericarp and high nutrient qualities were also discussed.
    Establishment of Transformation System and Genomic DNA Library of Magnaporthe grisea with Cosmid Vector
    Lu Guodong,Huang Danian,Tao Quanzhou,Yang Wei,Xie Lianhui
    1995, 9(3): 156-160 . 
    Abstract ( )   PDF (511KB) ( )  
    A new cosmid vector pSVhygB containing hygromycin B resistance gene and bacterlophage λcos site was constructed. Using the pSVhygB the genomic DNA library of Magnaporthe grisea was constructed. It showed that pSVhygB can stably transform M. grisea with frequency 15 transformants per microgram DNA and electroporation could not improved the transformation efficiency. There approximately had 10,000 recombinant clones in our genomic DNA library, more than that of the requirement for M. grisea.
    Protoplast Culture and Plant Regeneration in Wild Oryza Species with Promotion by Nurse Cell Liquid and Suitable Proliferation Media
    Xiang Youbin,Dong Yanjun
    1995, 9(3): 161-166 . 
    Abstract ( )   PDF (437KB) ( )  
    The protoplasts of three Oryza species (O. rufipogon, O. glumaepatula and O. latifolia) were successfully cultured by using agarose-bead method in simplified protoplast culture medium (SPCM) with or without the nurse cell liquid through cell suspensions from mature embryos. Two of them (O. rufipogon, O. glumaepatula) regenerated green plantlets from protoplast-derived calli. The nurse cell liquid covering agarose-bead protoplasts could promote cell division and significantly increase the frequency of cell division (33.2%) and colony formation (19.0%). The hardening for protoplast-derived calli on the suitable proliferation media greatly benefited green plantlet regeneration. In the course of callus hardening, L3 medium showed the highest efficiency (32.1%) in the formation of embryogenic calli and embryo-like structure, thus resulting in producing moregreen plants.
    Study on Anther Culture Ability of different Ecotypes of O. rufipogon Griff
    Pang Hanhua,Tang Shengxiang
    1995, 9(3): 167-171 . 
    Abstract ( )   PDF (191KB) ( )  
    Thirty-seven entries of O. rufipogon from China including three ecotypes named as stolon, slope and erectness were studied on anther culture ability. The result indicated that there existed a obvious differences in anther culture ability in the tested entries, in which the callus induction rate ranged in 0-9.1%, and green plantlet differentiation in 0-32.1%. Pollen green seedlings were obtained in 31 of the 37 entries. The anther culture ability in order was as follows: cultivated rice>interspecific hybrids>erectness ecotype>slope ecotype>stolon ecotype. Different media showed different efficiency of anther culture to the tested ecotypes. However, improved N6-1 medium was the best one suitable to all three ecotypes of O. rufiporgon, which could lead to apparent increase in the efficiency of anther culture.
    研究简讯
    Fusarium moniliforme var. zhejiangense Wang et H.K.Chen, A New Pathogen of Bakanae Disease of Rice
    Ye Qiming
    1995, 9(3): 172-172 . 
    Abstract ( )   PDF (63KB) ( )  
    研究报告
    Effects of Overcast and Raining on Flowering, Fertilizing and Seed Setting of Early Rice
    Zhang Yuzhu,Zhang Guihe,Zhu Guoqi,Deng Qiyun,Zhan Qingcai
    1995, 9(3): 173-178 . 
    Abstract ( )   PDF (394KB) ( )  
    The performance of flowering, fertilizing and seed-setting of 491 varieties of early rice was evaluated under the artificial simulation condition of overcast and raining, and so did adaptability of 39 varieties in the condition of natural overcast and raining during heading and flowering stages. The results indicate that rates of flowering, fertilizing and seed-setting reduced obviously in the condition of overcast and raining. Raining makes mainly flowering rate and fertilizing rate drop in a great extent, shading causes degradation of glume and increase of unfilled grains. The difference is significant among the tested varieties under the same conditions. The cleistogamic type rice varieties are better adaptable to overcast sky and raining.
    Selection Index for Screening Physiological Nitrogen Use Efficiency in Rice (in English)
    Wu Ping,Tao Qinnan
    1995, 9(3): 179-184 . 
    Abstract ( )   PDF (124KB) ( )  
    Physiological nitrogen use efficiency defined as efficiency in transferring nitrogen from terminal parts for grain production was used in this study. Selection index, in terms of higher expected response to selection for grain yield per unit total nitrogen absorbed (G/Nt) and the genotypic ability to transfer N from terminal parts for grain production, was investigated using an F2 population in a pot experiment. G/Nt, G and HI were significantly and negatively correlated with straw N concentration (SN%) and straw N content (SN) genetically. Three selection indices were established with the components of HI, G, SN% and SN. Path coefficient analysis indicates that the direct effects of the components of HI, G, SN% or SN were higher than the indirect effects in the selection indices. The expected responses on G/Nt to selection based on the developed selection indices were higher than or similar with that based on G/Nt alone. The selection indices composed of HI and SN% or based on G, SN% and SN could be used for screening G/Nt according to the higher expected response to selection and close correlationship with G/Nt. These selection indices are more clear in term of efficiency in N transportation from terminal parts for grain production.
    研究简报
    Studies on the Forecasting Models of Brown Planthopper, Nilaparvata lugens (Stal), in Zhejiang
    Coorperative Research Group for the Forecasting Model of Brown Planthopper in Zhejiang
    1995, 9(3): 185-188 . 
    Abstract ( )   PDF (173KB) ( )  
    Used the historical data over 15 years from five cities/counties, a group of forecasting models was established by means of stepwise regression. The models could forecast both emergent quantity and degree of the main endangering generation of brown planthopper (BPH) on late-season rice. Through eight-year forecasting and verifying, 73 models were chosen from 469 ones. These models, a complete group of forecasting models, could be used as long, middle and short term forecasting. The accurate rate of forecast was 93.98% for the whole, and 87.5%, 95.83 % and 100% for either. This forecasting method suited to more than 400 thousand ha paddy-field covered 23 cities/counties in Zhejiang. The middle and long term model could forecast 25 days and 55 days earlier than conventional forecasting method, respectively.
    The Isolation and Genetic Identification of a Semidwarf Gene from an indica Rice Variety Aitaiyin 2
    Liang Guohua,Pan Xuebiao,Gu Minghong,Ji Chaoqiu
    1995, 9(3): 189-192 . 
    Abstract ( )   PDF (268KB) ( )  
    In order to discover new semidwarf genes which can be used in breeding program in indica rice, a dwarf variety Aitaiyin 2, was crossed with a tall native cultivar Naming 6. The segregation of the F1 generation appeared to be 9 tall:6 semidwarf:1 dwarf, which meant two semidwarf genes were involved. While Aitaiyin 2 was also crossed with two semidwarf varieties, Nanjing 11 with sd-1 and Xingui'ai with sd-g, the segregation of the F2 generation in the former cross was 3 semidwarf:1 dwarf and that in the latter cross was 27 tall:27 semidwarf:9 dwarf:1 extra dwarf. This indicated that there were two semidwarf genes in Aitaiyin 2, one of them was allelic to sd-1 and the other was a new semidwarf gene which was nonallelic to both sd-1 and sd-g. This new semidwarf gene was named sd-t(t).