中文摘要：

本研究采用PCR-SSCP和DNA测序的方法检测了4个品种鸡（仙居鸡、白耳鸡、清远麻鸡和安卡鸡）Toll样受体4（Toll-like receptor 4,TLR4）基因第2内含子的单核苷酸多态性。结果表明,4个品种鸡TLR4基因的第2内含子上均发现了G1894C的突变,共产生了AA、AB和BB 3种基因型,4个品种鸡该位点的多态信息含量（PIC）分别为0.570、0.597、0.583和0.588,均属于高度多态性,且处于Hardy-Weinberg平衡状态（P〉0.05）;4个品种鸡G1894C多态位点的基因型在感染鸡白痢沙门氏菌阳性组和阴性组间的分布差异均不显著（P〉0.05）;G1894C多态位点在仙居鸡与白耳鸡2个品种间基因型分布差异极显著（P〈0.01）。

英文摘要：

The genetic distribution of the polymorphisms of intron 2 of TLR4 gene in four different chicken breeds including Xianju,Baier,Qingyuan,Anka chicken were tested by PCR-SSCP and DNA sequencing in this study.The results indicated that a G1894C mutation existed in four different chicken breeds.There were three genotypes of AA,AB and BB in all the breeds.The results showed that inspected locus was high diversity,the average polymorphism information content（PIC） were Xianju chicken 0.570,Baier chicken 0.597,Qingyuan chicken 0.583,and Anka chicken 0.588,respectively,and were accorded with the law of Hardy-Weinberg equilibrium.The genotypes of G1894C polymorphism locus was no significant differences between the positive and negative groups after chickens infected with Salmonella pullorum（P0.05）.Genotype distribution of G1894C polymorphism locus was highly significant difference between Xianju and Baier chicken（P0.01）,which would provide scientific basis and technological supporting for resistance-related gene analysis in future.