导　　师： 张英汉;马月辉;耿社民;秦国庆

学科专业： 090501

授予学位： 硕士

作　　者： ;

机构地区： 西北农林科技大学

摘　　要： 本研究利用微卫星标记技术，分析了黎城大青羊、吕梁黑山羊、阳城白山羊、新疆南疆山羊、新疆北疆山羊以及宁夏中卫山羊6个地方山羊品种的分子水平上的遗传多样性，探讨了各品种内遗传变异及群体间的遗传关系，研究结果如下： 1.筛选了到了19个微卫星位点，均在6个品种得到了特异性扩增结果，检测到了177个等位基因，平均每个位点达9.3个，最少为6个，可以较好地用于各品种内及品种间遗传多样性分析。有效等位基因数目总共为76个，有效等位基因数小于实际观察等位基因数，这是各等位基因频率分布不均匀的原因。 2.哈代－温伯格平衡检验结果表明：6个群体基本处于遗传不平衡状态；究其原因有随机交配发生偏移、遗传漂变以及选择等。 3.19个微卫星位点均为中度和高度多态位点，平均多态信息含量达0.6859～0.7083，6个品种具有丰富的遗传多样性。6个品种平均位点杂和度在0.3832－0.4277之间，杂和度较低，虽然有较高的多态信息含量，但还存在一定程度的近交，在以后的保种中应防止退化。 4.遗传分化系数表明：BM203、BM023、BMS6526、MAF65四个位点的GST估算值较大，分别为0.04755、0.0491、0.0107、0.0262，BM3033值最小，为0，这意味着前4个位点在不同品种间的基因分化占总群杂和度的4.755％、4.91％、1.07％、2.6％；其它位点GST值不高，这说明遗传变异主要存在于各个品种内，品种间遗传变异不大。 5.聚类结果表明：6个山羊品种并不因为地理分布而各自聚一类，以Nei氏遗传距离为基础的UPGMA法的聚类结果与前人研究结果一致，吕梁黑山羊与阳城白山羊具有较近的亲缘关系，此外UPGMA和N-J图中，黎城大青羊与新疆南疆山羊具有较近的亲缘关系；以共祖距离为基础的UPGMA和N-J聚类结果，� The genetic diversity of six native goats in China was surveyed using nintheen microsatellite loci.The six goats included Licheng cyan goat,lvliang black goat,Yangcheng white goat, Xinjiang goat in North, Xinjiang goat Sourth,Zhongwei goat.And the results were as follows: 1. The 19 microsatellite loci were seleted and the results of PCR were got in every locus.177 allelic were got in all the loci and the average number was 9.3 in one locus and the lest one was 6. All the loci could be used to analyse the genetic diversity of every breed.The effective allelic number wab 76 which was less than the observed allelic number. 2.The Hardy-Weinberg equilibrium analysis revealed that 6 breeds showed a remarkable genetic disequilibrium at all the loci.Maybe the reasons were that the size of the samples were less or in breeding existed in 6 breeds. 3.The 19 microsatellite loci showed middle high and high PIC value.The mean PIC value was between 0.6859-0.7083,which indicated that the 6 breeds had abundant genetic diversity. The mean heterozygosity was between 0.3832-0.4277. 4.The Cofficient of gene differentiation was largest in BM203, BM023, BMS6526, MAF65 loci.The Gst of other loci was not larger and the one of BM3033 was 0.The result showed that the gene differentiation was in every breeds and not remarkable in all the breeds. 5.Nei’s genetic distance and Coancestry genetic distance were estimate and used to construct UPGMA and NJ dendrograms.In the UPGMA and NJ dendrogram based the Nei’S genetic distance,lvliang black goat and the Yangcheng white goat were one cluster which was consistent with the former’s research. The UPGMA and NJ dendrograms based the Coancestry genetic distance had the difference with the former’s.But the 4 dendrograms showed that Xinjiang goat and the Shan’xi goat had the possibility that they had had common ancestor. 6. Based the allele frequencies of 17 microsatellite loci,the accuracy of Nei’s standard distance am

关 键 词： 山羊 微卫星 遗传多样性 遗传距离 聚类分析 遗传分化系数

领　　域： [农业科学] [农业科学]