关键词: 山羊; 地方品种; 群体结构; 遗传多样性贡献; 优先保护

Abstract: 【Objective】 This study aimed to analyze the population structure and conservation prioritization of 7 representative indigenous Chinese goat breeds,thereby promoting the conservation of goat genetic resources and the sustainable and healthy development of the goat industry. 【Method】 Genomic data from 63 individuals representing 7 indigenous Chinese goat breeds,including the Tibetan goat,Inner Mongolia cashmere goat,Liaoning cashmere goat,Xiangdong Black goat,Hainan Black goat,Guizhou Black goat and Luoping Yellow goat,were obtained using the Illumina 50K chip.Population structure was characterized through principal component analysis (PCA),phylogenetic tree and Admixture analysis,with PCA and Admixture results visualized using R Studio and the phylogenetic tree annotated and visualized using the online iTOL platform.By integrating the 7 representative breeds into a single metapopulation,the changes in total gene and allelic diversity were analyzed by sequentially removing each breed.Through simulation,the proportional contribution of each breed to the synthetic population in terms of gene and allelic diversity was assessed,thereby determining the conservation priorities among the breeds. 【Result】 In the population structure analysis,both PCA and phylogenetic tree results revealed that the seven breeds were distinctly divided into three branches:The Western & Northern branch,the Southeastern branch and the Southwestern branch.The Western & Northern branch included the Liaoning cashmere goat,Inner Mongolia cashmere goat and Tibetan goat;The Southeastern branch comprised the Xiangdong Black goat and Hainan Black goat;And the Southwestern branch encompassed the Guizhou Black goat and Luoping Yellow goat.Admixture analysis indicated that the optimal population structure was achieved at K=3. In the conservation prioritization analysis,the Z-score normalization of gene and allelic diversity revealed the following priority order for conservation efforts,from highest to lowest:Liaoning cashmere goat,Guizhou Black goat,Tibetan goat,Xiangdong Black goat,Inner Mongolia cashmere goat,Hainan Black goat and Luoping Yellow goat. 【Conclusion】 This study demonstrated that indigenous Chinese goat breeds could be classified into 3 distinct branches,with the Liaoning cashmere goat,Guizhou Black goat and Tibetan goat identified as priority breeds for conservation.These findings provide a scientific basis for the management of genetic resources in indigenous Chinese goats and offer valuable insights for optimizing conservation policies.

Key words: goat; indigenous breed; population structure; contribution to genetic diversity; conservation priority