中文摘要：

通过比对新城疫病毒强、弱毒株F基因序列，根据其在FO裂解位点的差异以及F基因保守序列设计合成NDv-V-probe和NDV-L-probe探针组和NDV-F、NDV-R引物组，以基因Ⅶ型NA-1株和基因Ⅱ型LaSota疫苗株病毒RNA作为定量检测的标准品，建立检测方法。对所建立的标准曲线进行分析，相关系数R。均为0．997，线性关系良好。通过计算变异系数Cv／％分别为0．034％和0．027％，均小于1％，说明稳定性良好。对禽类常见病毒IBV、H9亚型AIV检测未发现有交叉反应，特异性好、重复性佳。结果表明：成功建立了新城疫病毒强、弱毒双重荧光定量RT—PCR的检测方法，实现了从分子水平上快速鉴别强、弱毒力的新城疫病毒，也可快速区分野毒感染动物和疫苗接种动物，减少不必要的经济损失。

英文摘要：

In this study,we compared velogenic NDV F gene sequence with that of lentogenic,and then designed probes and primers according to the differences in the F0 cleavage site and the con- served sequences of F gene. NDV-F ＆ NDV-R were selected as the best primer sets and NDV-V- probe ＆ NDV-L-probe were selected as the best probe sets after screening groups of probes and primers, the genotype Ⅶ Newcastle disease virus NA-1 strain and the vaccine strain LaSota virus RNA were respectively treated as standard for the development of a duplex fluorescence quantita- tive RT-PCR detection method. The correlation coefficient R2 of the established standard was 0. 997,with a good linear relationship,and the coefficient of variation （CV/%） were 0. 034%0 and 0. 027% respectively,which were less than 1%,indicating a good stability. Avian virus IBV, H9- AIV were not found cross-reactivity, indicating its good specificity and repeatability. Taken to- gether,NDV velogenic and lentogenic strains can be distinguished rapidly using a duplex fluores- cence quantitative RT-PCR detection system, meanwhile, the detection system allows a strategy of differentiating infected from vaccinated animals,which could reduce unnecessary economic losses.