中文摘要：

从华南地区疑似传染性支气管炎的病料中,分离到6株传染性支气管炎病毒并对这些分离株进行鸡胚矮小化试验、新城疫病毒干扰试验、血凝特性试验、鸡胚气管环感染试验、S1基因的克隆测序与序列分析。结果表明,各分离株均对鸡胚有明显的致矮小化作用;对新城疫病毒有明显的干扰作用;无直接血凝性,经10g/L胰酶处理后,可凝集鸡的红细胞;对鸡胚气管环有明显的感染致病变作用;利用RT-PCR方法,成功扩增出分离株的S1基因,与参考株S1基因序列比对,其中1株（GD-09II）属于Mass型,剩下5株与LX4型亲缘关系较近。

英文摘要：

Six field strains of infectious bronchitis virus were isolated from suspected flocks from different time and different regions of South China,and characterized by a series of systematic identification assays respectively,such as virus pathological lesions to chicken embryoes,interfering with the propagation of Newcastle disease virus,hemagglutination activity,infection of tracheal organ cultures,clone and sequence analysis of S1 gene.The results showed that six isolates could dwarf with chicken embryos,the propagation of Newcastle disease virus strain was seriously interfered by the 6 isolates respectively,no direct hemagglutination activity was found,but it can agglutinate chicken red blood cells after treatment with 1% trypsin,the infection and cytopathic effect to tracheal organ cultures were obvious.The specific fragments of S1gene of the 6 isolates were amplified by RT-PCR,compared with S1 gene of reference strains,one of the six strains（GD-09II） was Mass type,and the rest were close to LX4 type.