中文摘要：

利用23对微卫星标记分析了中国南方7个山羊群体的遗传分化、基因流、遗传分化程度与地理距离之间的关系，同时利用DC遗传距离构建系统树和STRUCTURE进行动态聚类。结果表明：7个山羊群体总近交系数（Fis）为-7．73％，群体内近交系数（Fis）为-26．5％，群体间基因分化系数（Fis）为14．84％，3个指标均达到极显著水平（P〈0．001），说明这7个山羊群体总体上和群体内杂合度较高，群体间遗传分化较明显，14．84％的遗传变异来自于群体间，85．16％遗传变异来自于群体内个体间的差异。7个山羊群体每世代两群体间有效迁移个体数（Nem）变化范围为0．8313（宜昌白山羊与黄淮山羊）到3．4103（马头山羊与湘东黑山羊），平均为1．5770。7个山羊群体间的基因分化程度与地理距离和遗传距离相关不显著（P〉O．05）。宜昌白山羊、马头山羊、湘东黑山羊、福清山羊、戴云山羊、黄淮山羊、长江三角洲白山羊群体中属于各自采样群体的概率分别为99．1％、98％、96．2％、96．6％、98．7％、98．7％和98．7％。同时，STRUCTURE软件通过变化的分群数体现的聚类情况与用DC遗传距离所构建的系统聚类图结果一致。研究结果表明：这7个山羊群体间的遗传分化主要是自然选择作用的结果。

英文摘要：

The genetic differentiation, gene flow, the relationship between geographical distance and genetic differentiation among seven indigenous goat populations in south of China were estimated using 23 microsatellites. The trees were constructed from DC distances and the data were analyzed by STRUCTURE （Ver 2.0）. The global heterozygote excess across all populations （Fis） amounted to -7. 73% （P〈0. 001）. The overall significant （P〈0. 001） excess of heterozygotes within populations amounted to -26.5%. The 7 goat populations were highly differentiated （Fis = 14. 84%, P〈0. 001） at all loci, which indicated that 14. 84% of the total genetic variation came from breed differences, and the remaining 85.16% came from differences among individuals in each population. The average number of effective migrants exchanged per generation （Nero） ranged from 0. 831 3 （Yichang White goat and Huanghuai goat） to 3. 410 3（Matou goat and Xiangdong Balck goat）, and the average value was 1. 577 O. No significant positive relationships between the level of genetic differentiation and geographical distance, genetic distances among 7 goat populations were detected. With the application of prior population information, cluster analysis by STRUCTURE （Ver. 2.0） achieved posterior probabilities 99.1%, 98%, 96. 2%, 96.6%, 98. 7%, 98.7% and 98. 7% of correctly assigning sampling populations to different inferred clusters for Yichang White goat, Matou goat, Xiangdong Balck goat, Fuqing goat, Daiyun goat, Huanghuai goat and Yangtse River Delta White goat, respectively. The inferred clusters by STRUCTURE were similar with the trees constructed from DC distances. From the results it indicated that the reason for the genetic differentiation among seven indigenous goat populations in south of China is natural selection.