关键词: 家鸭, mtDNA 控制区, 单倍型, 遗传多样性

Abstract: Investigation of the genetic polymorphism and systematic evolution in domestic ducks by the structure and polymorphism of mitochondrial DNA. The 667 bp control region on mitochondrial DNA from 106 domestic ducks of 9 breeds was sequenced. The result showed that content of nucleotide A,C,G,T were 25.6%,33.3%,15.2% and 25.9%, respectively. There were 34 polymorphic sites (5.1% in total analyzed sites).The transition, transversion, and insertion/deletion were found in this region. 31 haplotypes were defined in this study, in which A7 was major haplotype in ducks and shared 9 haplotypes among breeds. The haplotype diversity(Hd) and average nucleotide diversity(Pi) were 0.798 and 0.28%, respectively. Hd was the highest in Jingjiang Sheldrake, followed then by Youxian Sheldrake and Enshi Sheldrake, and lowest in Wendeng Black duck. Kimura 2-parameter distance between the breeds is 0.001 3-0.004 4. A Phylogenetic analysis of the 31 haplotypes identified that there was only one distinct maternal lineage in domestic duck breeds and revealed that no evidence of contribution of Anas zonorhyncha to the maternal origin of domestic duck breeds.

Key words: domestic duck, mtDNA control region, haplotype, genetic diversity