黄淮杜泊羊线粒体DNA遗传多态性研究

线粒体DNA遗传变异丰富，是研究群体遗传多样性的重要手段。通过对黄淮杜泊羊、杜泊羊、鲁西黑头羊和小尾寒羊的线粒体D-loop遗传变异进行检测，分析4个品种的遗传多样性和品种间的遗传分化，构建系统发育树，并计算4个品种的遗传关系和遗传距离。结果表明，黄淮杜泊羊群体遗传多样性丰富（单倍型多样度h=0.984 21，核苷酸多样度P_i=0.015 50），遗传稳定；系统发育树黄淮杜泊羊的黑头群体和白头群体聚为一类，与鲁西黑头羊、杜泊羊和小尾寒羊明显区分；黄淮杜泊羊与杜泊羊遗传距离最近（0.055）、与小尾寒羊遗传距离最远（0.070），且黄淮杜泊羊与鲁西黑头羊、杜泊羊和小尾寒羊品种间遗传分化程度大。说明黄淮杜泊羊的遗传多样性丰富、遗传分化程度高，在遗传上明显区别于鲁西黑头羊、杜泊羊和小尾寒羊，黄淮杜泊羊黑头和白头群体的遗传一致，且群体遗传稳定，试验结果与育种设计方案相吻合，说明黄淮杜泊羊具备了新品种的遗传条件。

Study on mitochondria genetic polymorphism of Huanghuai Dorper sheep

The genetic variations of mitochondria DNA are abundant, which is an important tool to analyze genetic diversity of populations. In this study, through genetic variations within D-loop sequences among Huanghuai Dorper sheep, Dorper sheep, Luxi sheep and Xiaowei Han sheep, the genetic diversity and genetic differentiation were analyze. The phylogenetic tree was constructed to determine genetic relationship and genetic distance among breeds. It showed that Huanghuai Dorper sheep had highly genetic diversity (haplotype diversity h=0.984 21 and nucleotide diversity P_i=0.015 50), it exhibits well hereditary stability and will not lead to population degradation. The phylogenetic tree showed that White head population and Black head population of Huanghuai Dorper sheep were clustered together, Luxi sheep and Xiaowei Han sheep were clustered together, then clustered with Dorper sheep. The genetic distance of Huanghuai Dorper was nearest to Dorper sheep (0.055) and farthest to Xiaowei Han sheep (0.070). Huanghuai Dorper sheep displayed highly genetic differentiation with other three sheep breeds. In conclusion, Huanghuai Dorper sheep showed abundant genetic diversity, well hereditary stability and the genetic distance of which was consistent with its breeding strategy. Therefore, Huanghuai Dorper sheep has reached the genetic request for a new sheep breed and could be carried forward for marketing.