Abstract: Genome-wide association analysis (GWAS) was used to identify candidate genes and molecular markers which genes related to meat color traits in ducks and explored the genetic basis of meat color traits.In this study,three meat color phenotypes (including redness a^*,yellowness b^* and brightness L^*) were collected in 555 ducks from an F2 segregating population generated by Pekin duck×mallard crosses and performed GWAS using whole-genome resequencing data to detect SNPs loci associated with meat color traits.The results showed that the meat color L^*,a^* and b^* displayed low heritability which was 0.23,0.12 and 0.13,respectively,and the coefficient of variation for meat color yellowness (b^*) was 26.18%.Correlation analysis results showed that high positive phenotypic and genetic correlations between muscle yellowness and muscle redness (r=0.52),and low negative correlations between muscle fiber diameter and muscle yellowness (r=-0.16).GWAS was performed using a mixed linear model and potential significant SNP association with muscle yellowness (-log₁₀ P=8.28) was found.Then the loci of interest more closely was examined by calculating pairwise linkage disequilibrium (LD).42 SNPs spanning a region from 0.37 Mb to 0.43 Mb on chromosome 9 where contained 7 annotated genes were highly correlated (pairwise r²>0.4).The mRNA expression of five genes were expressed in breast muscle.By functional annotation of this 5 genes,SELENOT was identified as candidate gene for yellowness b^*,which provided an important reference for the genetic improvement of meat quality in ducks.

Key words: meat color; GWAS; SELENOT gene; duck