Abstract: Yangtze River Delta white goat is a local goat breed with excellent skin, meat and hair. In order to provide data support for the germplasm resources protection and breeding improvement, this study analyzed the genetic diversities and genetic structures of two purebred white goat populations and one hybrid population from Yangtze River Delta region by simple sequence repeat (SSR)  markers. The genetic diversity of Haimen goat (HM), Chongming white goat (CM) and hybrid white goat (ZY) from Chongming region were detected by PCR amplification and capillary electrophoresis with 30 microsatellite markers. Different genotypes at different SSR loci and population were analyzed. In HM, CW and ZY populations, the total numbers of alleles were 205, 191 and 147, the average effective alleles (Ne) were 4.012, 3.812 and 3.092, the average numbers of expected heterozygosity (He) were 0.683, 0.668 and 0.617, and the average polymorphism information contents (PIC) were 0.647, 0.630 and 0.567, respectively. The total inbreeding numbers (Fit), mean genetic differentiation coefficients (Fst) and mean gene flows (Nm) of three populations were 0.011 0, 0.050 7 and 4.680 6. The genetic distance of ZY was closer to CM  than with HM. UPGMA analysis showed that CM and ZY were gathered together. Two purebred white goat populations from conservation goat farms and hybrid population from Chongming all showed high heterozygosity, high polymorphism, moderate genetic differentiation, gene exchange, little influence by inbreeding degree, and had high utilization value and potential, which could be used for the conservation and utilization of germplasm resources.

Key words: Yangtze River Delta white goat, microsatellite, genetic diversity, genetic distance

摘要： 长江三角洲白山羊是皮、肉、毛兼优的地方山羊品种。通过微卫星标记（SSR）对长江三角洲白山羊保种群体进行遗传多样性分析，可为种质资源保护和品种改良提供数据支持。选取30个SSR标记，采用PCR扩增和毛细管电泳技术检测海门山羊、崇明白山羊和崇明地区杂交白山羊的遗传多样性。对各群体不同位点和各位点不同基因型进行分析。海门山羊、崇明白山羊和崇明地区杂交山羊群体中等位基因总数分别为205、191和147个，平均有效等位基因数（Ne）为4.012、3.812、3.092，平均期望杂合度（He）为0.683、0.668、0.617，平均观测杂合度（Ho）为0.726、0.691、0.633，平均多态信息含量（PIC）为0.647、0.630、0.567。三个群体的平均近交系数（Fis）为0.011 0，平均遗传分化系数（Fst）为0.050 7，平均基因流（Nm）为4.680 6。杂交山羊和崇明白山羊的遗传距离较近，和海门山羊遗传距离较远。系统进化树聚类分析表明，崇明白山羊与崇明杂交山羊聚为一类。两个纯种长江三角洲白山羊群体和杂交群体均表现出较高的杂合度、多态性和遗传变异；两个保种群体为中度遗传分化，近亲繁殖率低，存在基因交流，可用于种质资源的保存和利用。

关键词: 长三角洲白山羊, 微卫星, 遗传多样性, 遗传距离