江苏省自然科学基金(BK20221412), 江苏省种业振兴“揭榜挂帅”（JBGS029）, 国家重点研发计划(2021YFD1200302), 江苏现代农业产业技术体系建设专项资金(JATS399)和国家自然科学基金(31501917, 31672382, 31702079, 31372277)共同资助。
This research aimed to characterize the MC1R gene polymorphism of Chinese black-plumage chicken breeds. Seven black plumage chicken breeds (Langshan, Shouguang, Dongxiang Blue-eggshell, Yanjin Black-bone, Yugan Black-bone, Hongguang black, and Xinyang black) were collected, the sequence of the MC1R gene was PCR amplified, sequenced and analyzed by bioinformatics. The complete CDS of the MC1R gene of seven breeds were all 945 by in length encoding a predicted polypeptide of 315 amino acids. A total of 10 polymorphic sites were found in 210 sequences of seven chicken breeds, including 9 polymorphic loci in the coding region, of which seven were non-synonymous mutations that cause amino acid changes. The 14 haplotypes were observed based on 10 polymorphic sites. Dongxiang Blue-eggshell and Shouguang had two haplotypes, the other breeds all had two more haplotypes. The phylogenetic analysis revealed two groups, Group I consisted of Xinyang black chicken, and the other six black plumage chicken breeds were distributed in Group II. Our data suggested abundant genetic polymorphism in the chicken MC1R gene, which could be regarded as markers for the Chinese native breed and foreign blood breed of chicken. Therefore, this work will provide the theoretical basis for further evaluation studies, preservation, and utilization of Chinese black-plumage chicken breeds.