运用模型分类法分析9个地方鸡品种间遗传结构和亲缘关系

Analysis of Genetic Structure and Relationship among Nine Chinese Indigenous Chicken Breeds by Using Model-based Cluster Method

以16个中度或高度多态性微卫星标记,运用基于模型分类法的Structure程序推断9个地方鸡品种群体遗传结构,构建聚类图分析相互间亲缘关系,并鉴定群体中迁移个体和具有复杂遗传基础个体的分布。结果表明:Structure程序在预先未标明品种起源的条件下准确推断出9个地方鸡种群体所属类别,揭示按照体型外貌、地理分布等为依据划分的9个地方鸡品种类型,也真实反映了其在遗传上的差异。Structure聚类图在K=2时将9个地方鸡种分为轻体型的鸡种(包括茶花鸡、藏鸡、仙居鸡、固始鸡和白耳鸡)和重体型的鸡种(包括大骨鸡、北京油鸡、鹿苑鸡和萧山鸡)两个类别;K=4、5、6时北京油鸡、固始鸡、大骨鸡分离出来形成独立类群;仙居鸡与白耳鸡在K=6、萧山鸡与鹿苑鸡在K=7、藏鸡与茶花鸡在K=8时仍聚在同一类别中,这与9个地方鸡种的地理分布及形成历史相吻合。9个地方鸡品种群体中均有具有复杂遗传基础的个体分布,迁移个体只分布在藏鸡、萧山鸡和鹿苑鸡群体中。

The Structure program, based on model clustering method, was used to infer the genetic structure of nine indigenous chicken breeds, assign individuals to populations, and identify migrants and admixed individuals using 16 microsatellite markers. The results showed that Structure program properly inferred the presence of genetic structure at the condition of not defining the origin of individuals. It indicated that the nine chicken breeds defined by locations, phenotypes or culture reflected the underlying genetic variations. At K=2, nine breeds were divided into two main clusters, one was light weighted （including CHA, TIB, XIA, GUS and BAI） , the other was heavy weighted （including YOU, XIS, LUY and DAG）. YOU, GUS and DAG were classified into independent clusters respectively at K=4,5, 6. XIA and BAI, XIS and LUY, TIB and CHA were still belongs to one cluster at K=6,7,8. This was consistent with locations and breeding history of the nine breeds. The admixed individuals distributed in all the nine breeds, but migrants only distributed in TIB, XIS and LUY populations.