Genetic Diversity and Population Structure Analysis of Luhua chickens Based on Genome-Wide Markers

The Luhua chicken is an outstanding local breed in China that has been placed under conservation due to the impact of specialized breeding and the widespread adoption of commercial varieties. As such, this study analyzed reproductive traits across three consecutive generations and utilized whole-genome resequencing data from 60 Luhua chickens to assess conservation efficacy through genetic diversity, run of homozygosity (ROH) distribution, kinship, and population structure so as to better conserve the breed. The results show that, across generations, the body weight at first egg increased, the age at first egg was delayed, and the egg weight at first laying increased. No significant variations were found in the body weight at 300 d or the total egg number. The key genetic parameters of the polymorphism information content (PIC), expected heterozygosity (HE), observed heterozygosity (HO), and mean identical-by-state (IBS) distance were 0.234, 0.351, 0.277, and 0.782, respectively. The majority of ROHs ranged from 0.5 to 1 Mb, and the inbreeding coefficient based on ROHs was calculated at 0.021. The findings reveal that these traits remained unchanged across the three generations. Our research suggests that optimizing the mating plan of Luhua chickens is essential to minimize inbreeding risk. Furthermore, the methodology applied in this study provides a valuable reference for the conservation monitoring of other indigenous chicken breeds.