【作者】 杨述林；

【导师】 李奎；

【作者基本信息】 华中农业大学 ， 动物遗传育种与繁殖， 2004， 博士

【摘要】 中国是世界上猪品种资源最丰富的国家，联合国粮农组织家畜多样性信息系统中记载的中国家猪品种有128个。近几十年来，随着市场经济的发展，国外生长速度快、瘦肉率高的商用猪种大量引入中国市场，使各类养殖户对地方品种的偏爱下降，导致各地方品种的现有数量及纯度令人担忧，许多品种已处于濒危边缘。地方猪品种遗传多样性的研究和保护工作早已提上日程，利用联合国粮农组织和国际动物遗传学会推荐的微卫星标记对中国猪品种遗传多样性评估将为中国猪品种的保护提供理论依据，由此启动了“全国地方猪遗传距离测定”项目。本研究对十八个中国地方猪品种遗传多样性的分析作为该项目的重要组成部分，得到的结论有： （1） 联合国粮农组织和国际动物遗传学会所推荐的这套微卫星标记在本研究的18个地方猪品种中都具有丰富的多态性，等位基因数最少的有8个（SW951），最多的有31个（CGA和S0005），平均为19.34；多态性信息含量最低的是0.584（S0218），最高的是0.896（CGA），平均值为0.773；所有地方猪品种在22个座位上共享57个等位基因；没有发现品种特异的等位基因。 （2） 以Cavalli-Sforza和Edwards的余弦距离D_C和Nei氏D_A遗传距离绘制的NJ聚类图完全一致；以Nei氏D_A距离构建的NJ和UPGMA聚类树不完全一致；用UPGMA得到的聚类树与品种实际的地理分布更接近，聚类结果与《中国猪品种》中的分类约有差异； （3） 在UPGMA聚类树中，形成了内部稳定的两大支和外围分支，外围分支包括华北型品种民猪、马身猪和华南型品种香猪、滇南小耳猪；内部两支分别以华中型品种及西南型品种为主，以华中型品种为主的分支包括华中型品种沙子岭猪、大围子猪、宁乡猪、桃源猪、西南型品种盆周山地猪和华北型品种河套大耳猪；以西南型品种为主的分支首先是西南型品种柯乐猪、富源大河猪、荣昌猪、成华猪、内江猪和高原型品种藏猪聚到一起，再与关岭猪和汉江黑猪相聚。 （4） 将本研究的18个地方猪品种与“中国地方猪种遗传距离测定”项目中的所有品种一起聚类时，民猪与其它华北型品种相聚类，香猪和滇南小耳猪与其它华南型品种相聚类，与《中国猪品种》的分类不相符的是华北型品种汉江黑猪与西南型品种相聚类，华北型品种河套大耳猪与华中型品种相聚类。 （5） 微卫星每代突变率取4.5×10^-4和8.0×10^-5时，使用Nei氏标准遗传距离，得到中国猪地方品种间分化时间分别位于413.8-2036.8年之间和2327.8-11457.2年之间；中国地方品种与三个商用品种间平均分化时间分别为2400.4年和13803.95年。华中农业大学博士学位论文（6）本研究的18个地方品种中，马身猪需要重点保护，其它品种内仍存在较大的遗 传变异，且品种的群体数量大，可以在设立保种场的前提下，根据各品种的特点 将保种和开发利用结合起来，实现品种保护的经费自给。（7）从21个品种中各自随机抽出20头个体作聚类分析，各品种都形成有主分支， 主分支中的个体总计有387头:以个体对品种的基因频率和基因型似然比为标准 时，对各地方品种的全部个体作品种判别，其准确率分别达到98.45%和99.91%， 选用遗传距离类中的DPs，Ds，D，，岛及Dc时，判别的准确率分别达到97.16%， %.73%，%.82%，99.31%和98.88%。说明这套标记适合于地方猪品种个体判别 分析。（8）对品种鉴定的基准群体大小和座位数作综合比较分析得到，基准群体大小与座 位数的乘积达500（50头个体X10座位、加头x25个座位）以上时，判别的准确 率可达94%以上。更多还原

【Abstract】 Chinese was famous for the abundance of the indigenous pig breeds. There were 128 indigenous pig breeds recorded in the Domestic Animal Diversity Information System of FAO. However, lots of commercial pig breeds with high performance of growth and meat factor were introduced into China in the last decades for the market demand. The farmer would like to feed the crossbred between these breeds and indigenous pig breed or just the commercial breeds, rather than the indigenous pig breed, which leaded to the size of each indigenous pig breed decreased dramatically and many of them were endangered. Studying on the genetic diversity of Chinese indigenous pig breeds have been carried out in nowadays. The study result of genetic diversity of Chinese indigenous pig breeds with the microsatellite markers recommended by the FAO-ISAG would present the gist for conservation of these breeds. This study is one of the important parts of the project "Measurement of the genetic distance between Chinese indigenous pig breeds" launched in the autumn of 1999. The conclusion was followed as:(1) In this study, all of these markers were polymorphic in the 18 Chinese indigenous pig breed, the smallest number of alleles was 8 (SW951), the largest one was 31 (CGA and S0005), the average was 19.34; the lowest polymorphic information content was 0.584 (S0218), the highest one was 0.896 (CGA), the average was 0.773; all of these breeds shared 57 alleles in 22 loci, but there was no specific allele for a breed.(2) The Neighbor-Joining trees constructed from the Cavalli-Sforza and Edwards’ chord distance Dc and Nei’s genetic distance Da were consistent with each other; but the NJ and UPGMA trees produced from the Da genetic distance had some difference between them; the cluster tree of these breeds with the UPGMA was closer to the distribution of these breeds in geography, and it also had some difference from the classification of them in the book of Pig Breed in China.(3) The UPGMA tree was consisted of one small peripheral breeds and two steady inner branches, the peripheral breeds included the Min pig and Mashen pig of the North China Type and the Xiang pig and Diannan Small-ear pig of the South China Type; the two inner branches were mainly consisted of the Central China Type and Southwest Type respectively, the former branch included the breeds of the Shazhi Ling pig, Daweizhi pig, Ningxiang pig and Taoyuan pig from the Central China Type, the Pengzhou Mountanious pig from the Southwest Type and the Hetao Large-ear from the North China Type; in the later branch, the breeds of the Kele pig, Fuyuan pig, Rongchang pig, Chenghua pig and Neijiang pig and the Tibeta pig from the PlateauType clustered together firstly, then met the Guanling pig from the Southwest Type and the Hanjiang Black pig from the North China Type.(4) When the 18 indigenous pig breeds analyzed with other breeds in the project "Measurement of the genetic distance between Chinese indigenous pig breeds", the Min pig clustered with other breeds from the North China Type, the Xiang pig and Diannan Small-ear pig clustered with other breeds from the South China Type. But the Hanjiang Black pig clustered with the breeds from the Southwest China Type and the Hetao Large-ear pig clustered with the breeds from the Central China Type, which was not consistent with the classification in the book of Pig Breed in China.(5) Supposed the mutation rate of the microsatellite was 4.5 x 10-4 and 8.0 x 10-5 per year, the estimated differentiation time among the Chinese indigenous pig breeds were ranged from 413.8 to 2036.8 and 2327.8-11457.2 year from the Nei’s standard genetic distance, respectively. The average differentiation time between the indigenous pig breeds and the commercial breeds were 2400.4 and 13803.95 with different mutation rate of the microsatellite.(6) More attention on breed conservation should be given to the Mashen pig in the 18 Chinese indigenous pig breeds. There was great genetic variation stored in other breeds who had large population. The utlization更多还原