Chinese Domestic Ducks Evolved from Mallard Duck (Anas platyrhynchos) and Spot-Billed Duck (A. zonorhyncha)

SIMPLE SUMMARY: Domestic duck populations in China have abundant genetic resources, and this study is the first to evaluate domestic and wild Mallard populations. To explore the genetic diversity and ancestry of duck populations, we analyzed a sequence (619–667 bp) of mitochondrial DNA (mtDNA) in the control region. Two Muscovy duck breeds were included in this analysis, along with wild Mallard ducks, Eastern spot-billed ducks, and 22 domestic duck breeds. Significant genetic diversity was found among domestic duck breeds. These results not only provide valuable insights into the genetic makeup of domestic ducks but also provide clues to the possible origin of domestic ducks in China. ABSTRACT: China has a rich genetic resource in its 34 domestic duck breeds. In order to detect the genetic diversity and explore the origin of these indigenous duck populations, the mitochondrial DNA (mtDNA) control region was sequenced and analyzed for 208 individual ducks, including 22 domestic breeds, wild Mallards ducks, Eastern spot-billed ducks, White Muscovy ducks, and Black Muscovy ducks. The haplotype diversity (Hd) was 0.653 and the average nucleotide diversity (Pi) was 0.005, indicating moderate genetic diversity. Sixty haplotypes were detected, and the maximum-likelihood (ML) phylogenetic tree and median-joining (MJ) network were generated from the sequence analyses. In this study, haplotypes from the Mallard duck (Anas platyrhynchos) were detected in most of the Chinese domestic duck breeds. In addition, the Eastern spot-billed duck (A. zonorhyncha) H8 haplotype was detected in two duck breeds. Only two haplotypes were found in Muscovy ducks, suggesting low genetic diversity within this population. The sequence and haplotype analyses revealed that both A. platyrhynchos and A. zonorhyncha contributed to the evolution of domestic ducks in China.