【作者】 苏瑛；

【导师】 任继周； 龙瑞军； 陈国宏；

【作者基本信息】 甘肃农业大学 ， 草业科学， 2006， 博士

【摘要】 我国幅员辽阔,地大物博,拥有非常丰富的家禽遗传资源,是养鸭最早的国家之一。在漫长的驯养历史过程中,经过环境变迁、地理隔离、自然选择和人工培育,中国鸭品种已形成了许多特色和优良种质特性。本研究利用17个微卫星标记,对中国9个地方鸭品种及一个野鸭种群共516个个体进行DNA多态性测定。对等位基因频率进行Hardy-Weinberg平衡检验,分别计算等位基因数Na、平均基因杂合度H、多态信息含量PIC;估计有效等位基因数Ne和用来测量群体间的遗传分化程度的指标的F-统计量、基因分化系数Gst;依据Fst值估计基因流Nm;并采用Nei标准遗传距离法Ds(Nei’s standard genetic distance )和Cacalli-Sforza和Edward的弦遗传距离Dc计算各个品种间的遗传距离和遗传相似系数;在此基础上,采用UPGMA及NJ法构建系统发生树,估算了遗传分化时间。结果表明,所使用的鸭微卫星扩增产物稳定、清晰,发现66个私有等位基因,188个共有等位基因,平均等位基因数为7.24个,平均有效等位基因数为4.1个,平均基因杂合度(H)为0.6896,平均多态信息含量(PIC)为0.6506,其中PIC > 0.5的占84.7%,PIC在0.25-0.50之间的占15.2%. PIC在0.25以下的占5.9%,说明我们所选用的鸭微卫星标记可以提供可靠的信息,完全能够满足鸭研究的需要。中国主要地方鸭品种的杂合度在0.6044～0.7523之间,平均杂合度为0.6896, PIC在0.5606～0.7174之间,可见由微卫星标记所表现出来的中国主要地方鸭品种的遗传差异较大、遗传多样性较丰富。中国主要地方鸭不同品种间的Nei标准遗传距离Ds在0.1947~0.8219之间,平均遗传距离为0.4837,群体间一致性在0.1781-0.8369之间,群体间平均一致性为0.6729,连城鸭与其它鸭群体间的平均一致性只有0.4166。说明中国鸭种出现了一定程度的遗传分化,特别是连城鸭、荆江鸭、绍兴鸭分别与其它鸭种的分化最为明显。采用NJ法和UPGMA法构建了中国地方鸭种的系统发育树。根据系统发育树推断中国主要地方鸭品种不是单一起源于绿头野鸭。系统聚类结果与中国主要地方鸭品种的遗传分化式样与品种的地理分布型有很大的相关性,表现为地理分化的物种形成模型。中国主要地方鸭品种大致可以分为五支。一支为北京鸭、荆江鸭;一支为中山鸭、建昌鸭及高邮鸭;一支为靖西大麻鸭和金定鸭;连城鸭为一支;绍兴鸭为另一支。金定鸭与北京鸭间的基因流更多还原

【Abstract】 China, as one of the largest duck producers in the world, is rich in duck genetic resources .and there are many local breeds scattered throughout the country. and there are many local breeds scattered throughout the country. Many populations of ducks were formed through migration, segregation, natural selection, and artificial breeding, which had particularly excellent characteristics of germplasm. Most of them are often maintained in small populations given their low to medium performance in egg production and growth rate. Being less productive, they are threatened by the commercial varieties utilized by large domestic and foreign breeding companies. There were few research works in duck microsatellite in domestics and overseas. To study the phyiogenetic relationships and evolution of local ducks in China, using the nine local duck breeds and one mallard (Anas platyrhynchos), 516 individual, have been surveyed and their blood samples collected. Then the genetic diversity of these breeds was analyzed by seventeen microsatellite markers. Possible divergence from Hardy-Weinberg expectations was determined. Gene heterozygosity per locus and population (H), mean number of alleles per locus, PIC, the average observed number of alleles and the effective number of alleles were calculated. The parameters Fit, Fst, and Fis, the coefficient of gene differentiation (Gst) were calculated. Bonferroni’s procedures (Weir,1996) were applied when necessary. Results show, 17 microsatellites can amplify products with stable and clear bands. Of the 17 microsatellite loci, the number of alleles ranged from 1 to 14 per locus. There are 66 private alleles and 188 communion alleles. The average observed number of alleles is 7.24. The effective number of alleles is 4.1. The average heterozygosity value (H) and polymorphism information content (PIC) is 0.6896 and 0.6506 respectively, and there are 84.7% microsatellite with PIC above 0.5, and 15.2% with 0.25-0.5%, and 5.9% below 0.25. These suggest that microsatellite markers we selected can provide reliable更多还原