Canine coronavirus(CCoV),a member of the genus Alphocoronavirus,is an enveloped,single-stranded positive-sense RNA virus that responsible for gastroenteritis in dogs.In this study,two CCoV isolates were successfully p...Canine coronavirus(CCoV),a member of the genus Alphocoronavirus,is an enveloped,single-stranded positive-sense RNA virus that responsible for gastroenteritis in dogs.In this study,two CCoV isolates were successfully propagated from 53 CCoV-positive clinical specimens by serial passaging in A-72 cells.These two strains,CCoV JS1706 and CCoV JS1712,caused cytopathic effects in A-72 cells.The sizes of virus plaque formed by them differed in early passages.Electron microscopy revealed a large quantity of typical coronavirus particles with 80-120 nm in diameter in cell culture media and cytoplasm of infected cells,in which they appeared as inclusion bodies.RT-PCR analysis of 5 gene indicated that these two isolates were belonged to CCoV lla subtype.Homology of RdRp,S,M and N proteins between the two strains were 100,99.6,99.2 and 100.0%,respectively,whereas they were 99.4-100%,83.1-95.2%,88.5-99.2% and 91.9-99.7%identity compared to CCoV II reference strains.Phylogenetic analysis of RdRp,S,M and N protein showed that they were closely related to CCoV II strains.These two subtype lla isolates will be useful for evaluating the pathogenesis and evolution of CCoV and for developing diagnostic reagents and vaccines.展开更多
The effects of different nitrogen application rate on the physical characteristics and anatomic structure of rice stems were investigated with rice cultivars Guangliangyou 1128 （with high resistance） and Zhunliangyo...The effects of different nitrogen application rate on the physical characteristics and anatomic structure of rice stems were investigated with rice cultivars Guangliangyou 1128 （with high resistance） and Zhunliangyou 527 （with low resistance） as materials. The results showed that, firstly, plant height, gravity center height and basal internode length of the 2 rice cultivars increased with the increase of nitrogen application rate, while wall thickness and internode filling degree decreased. The breaking-resistance strength per stem and thrust-resistance strength of plants declined with the increase of nitrogen application rate. Secondly, as nitrogen input increased, the number of vascular bundles and the area of vascular bundles increased between the 2 rice cultivars. Thirdly, with the increase of nitrogen application rate, the stem section area of Guangliangyou 1128, which had strong lodging resistance, gradually increased, while that of Zhunliangyou 527 increased firstly and then decreased. The maximum application amount of nitrogen was 240 kg/hm 2. Nitrogen fertilizer mainly affected the relative gravity center height, stem wall thickness and internode filling degree of the 2 cultivars, thereby reducing the basal stem breaking resistance and plant thrust-resistance strength.展开更多
基金This work was supported by the Open Project Program of Jiangsu Key Laboratory of Zoonosis(No.1604,No.1804)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Canine coronavirus(CCoV),a member of the genus Alphocoronavirus,is an enveloped,single-stranded positive-sense RNA virus that responsible for gastroenteritis in dogs.In this study,two CCoV isolates were successfully propagated from 53 CCoV-positive clinical specimens by serial passaging in A-72 cells.These two strains,CCoV JS1706 and CCoV JS1712,caused cytopathic effects in A-72 cells.The sizes of virus plaque formed by them differed in early passages.Electron microscopy revealed a large quantity of typical coronavirus particles with 80-120 nm in diameter in cell culture media and cytoplasm of infected cells,in which they appeared as inclusion bodies.RT-PCR analysis of 5 gene indicated that these two isolates were belonged to CCoV lla subtype.Homology of RdRp,S,M and N proteins between the two strains were 100,99.6,99.2 and 100.0%,respectively,whereas they were 99.4-100%,83.1-95.2%,88.5-99.2% and 91.9-99.7%identity compared to CCoV II reference strains.Phylogenetic analysis of RdRp,S,M and N protein showed that they were closely related to CCoV II strains.These two subtype lla isolates will be useful for evaluating the pathogenesis and evolution of CCoV and for developing diagnostic reagents and vaccines.
基金Supported by the National Key R&D Program of China during the 13th Five-Year(2016YFD030010803)the Project for the Key(Preponderant)Discipline of Crop Science(Yangtze University)of Hubei Provincethe Training Program of Innovation for Undergraduates of Hubei Province(201810489059)
文摘The effects of different nitrogen application rate on the physical characteristics and anatomic structure of rice stems were investigated with rice cultivars Guangliangyou 1128 （with high resistance） and Zhunliangyou 527 （with low resistance） as materials. The results showed that, firstly, plant height, gravity center height and basal internode length of the 2 rice cultivars increased with the increase of nitrogen application rate, while wall thickness and internode filling degree decreased. The breaking-resistance strength per stem and thrust-resistance strength of plants declined with the increase of nitrogen application rate. Secondly, as nitrogen input increased, the number of vascular bundles and the area of vascular bundles increased between the 2 rice cultivars. Thirdly, with the increase of nitrogen application rate, the stem section area of Guangliangyou 1128, which had strong lodging resistance, gradually increased, while that of Zhunliangyou 527 increased firstly and then decreased. The maximum application amount of nitrogen was 240 kg/hm 2. Nitrogen fertilizer mainly affected the relative gravity center height, stem wall thickness and internode filling degree of the 2 cultivars, thereby reducing the basal stem breaking resistance and plant thrust-resistance strength.
