八个绵羊品种遗传多样性分析及引进肉用品种与地方品种杂种优势预测

Study on Genetic Diversity of Sheep Breeds and Forecast of Heterosis of the Import Mutton Sheep and Local Sheep

利用5个微卫星标记在山西省主要8个绵羊品种中的多态性研究,预测进口肉用绵羊品种与地方绵羊品种的杂种优势,为山西省肉用绵羊生产提供理论依据。结果表明,8个绵羊品种在5个微卫星位点上平均等位基因数在6.0-8.6个之间,平均有效等位基因在3.81-5.68个之间,平均基因杂合度在0.6711-0.7896之间,平均多态信息含量在0.6152-0.7462之间,品种间遗传分化系数为0.1390。说明选择5个微卫星座位均为高度多态位点,可用于8个绵羊品种遗传多样性评估;8个绵羊品种在5个微卫星座位上都存在较大的遗传变异,且总群体86.1%遗传变异发生在品种内。根据标准遗传距离和Nei＇s遗传距离,若用本地绵羊、广灵大尾羊做母本,父本选择顺序依次为特克赛尔羊、杜泊羊、萨福克羊、道赛特羊;若用小尾寒羊做母本,父本选择顺序为特克赛尔羊、萨福克羊、杜泊羊、道赛特羊。若用乌珠穆沁羊做母本,父本选择顺序为特克赛尔羊、萨福克羊、道赛特羊、杜泊羊。进口肉用绵羊品种与地方绵羊品种最理想杂交组合为：特克赛尔羊与本地绵羊、广灵大尾羊、小尾寒羊;较差杂交组合为：道赛特羊与小尾寒羊、乌珠穆沁羊,杜泊羊与乌珠穆沁羊。

The paper aimed at studying the polymorphism of eight sheep breeds in Shanxi province using five microsatellite DNA markers,to predicate the heterosis of import mutton sheep and local sheep,which could help understanding the utilization of mutton sheep in Shanxi province.The results showed that the average number of alleles of eight sheep breeds in five microsatellite loci was between 6.0 and 8.6,the average effective number of alleles ranged from 3.81~5.68,the average heterozygosity was between 0.6711 and 0.7896,the average of polymorphism information content was between 0.6152 and 0.7462,and the genetic differentiation coefficient among eight breeds was 0.1390.The five microsatellite loci was high in polymorphism,which could be used to study the genetic diversity of eight sheep breeds;the genetic variation was very abundant in the five microsatellite loci,and the 86.1percent genetic variation of total population mainly consisted in each breed.According to standard genetic distance and Nei＇s genetic distance,the local sheep and Guangling Large-tailed sheep were used for mother,and father were Texel,Dorper,Suffolk and Dorset in turn;Small-tailed Han sheep was used for mother,and Texel,Suffolk,Dorper and Dorset were chosen for father.U jumqin sheep was used for mother,and Texel,Suffolk,Dorset and Dorper werechosen for father in turn.The best hybridized combinations of import mutton sheep and local sheep were Texel used for father and local sheep,Guangling Large-tailed sheep and Small-tailed Han sheep used for mother;the lower hybridized combinations were Dorset used for father and Small-tailed Han sheep,U jumqin sheep used for mother,Dorper was used for father and mother was U jumqin sheep.