Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học thế giới đề tài: Genetic variation and relationships of eighteen Chinese indigenous pig breeds | 657 Genet Sei. Evol. 35 2003 657-671 INRA EDP Sciences 2003 DOI gse 2003045 Original article Genetic variation and relationships of eighteen Chinese indigenous pig breeds Shu-Lin Yanga b Zhi-Gang Wangb Bang Liua Gui-Xiang Zhangb Shu-Hong Zhaoa Mei Yua Bin Fana Meng-Hua Lia Tong-An Xionga Kui Lia a LaboratorY of Molecular Biology and Animal BreedinG School of Animal Science and Veterinary Medicine Huazhong Agricultural University Wuhan 430070 . China b Center of Preservation and Utilization of Germplasm Resource of Animal Husbandry and Forage Grass National Animal Husbandry and Veterinary Service Ministry of Agriculture Beijing 100094 . China Received 14 June 2002 accepted 31 March 2003 Abstract - Chinese indigenous pig breeds are recognized as an invaluable component of the world s pig genetic resources and are divided traditionally into six types. Twenty-six microsatellite markers recommended by the FAO Food and Agriculture Organization and ISAG International Society of Animal Genetics were employed to analyze the genetic diversity of 18 Chinese indigenous pig breeds with 1001 individuals representing five types and three commercial breeds with 184 individuals. The observed heterozygosity unbiased expected heterozygosity and the observed and effective number of alleles were used to estimate the genetic variation of each indigenous breed. The unbiased expected heterozygosity ranged between Mashen and GuanlinG which implies that there is an abundant genetic variation stored in Chinese indigenous pig breeds. Breed differentiation was shown by fixation indices Fit Fis and Fst . The Fst per locus varied from S0090 to SW951 and the average Fst of all loci was which means that most of the genetic variation was kept within breeds and only a little of the genetic variation exists between populations. The Neighbor-Joining tree was constructed based on the Nei Da 1978 distances and one large cluster with all local breeds but the .