Origin and genetic diversity of Chinese domestic ducks.

China is particularly rich in duck genetic resources. In order to reveal the genetic diversity and origin of Chinese domestic duck, the 667 bp control region of mitochondrial DNA of 238 domestic ducks from 26 indigenous breeds, 25 wild mallards and nine spot-billed ducks were sequenced and analyzed them together with the published data for 12 mallards and nine spot-billed ducks. The haplotype diversity (Hd, 0.645) and average nucleotide diversity (Pi, 0.115%) indicate low genetic diversity of Chinese domestic ducks. The NJ phylogenetic tree and reduced median-joining network chart were constructed using a total of 72 haplotypes. The genetic contribution of mallard (Anas platyrhynchos) can be detected in most of Chinese indigenous duck breeds and that of spot-billed duck (Anas zonorhyncha) can also be detected in few Chinese indigenous duck breeds. The results indicated that the Chinese domestic ducks mainly derived from mallard (A. platyrhynchos) and few derived from spot-billed duck (A. zonorhyncha).