Genetic variation of 20 autosomal STR loci in the Han nationality in Central Yunnan, Southwest China

•Phylogenetic analysis was used to explore genetic relationships between the Central Yunnan Han group and other populations.•Population comparisons between Central Yunnan Han and 17 previously published populations.•These 20 STR loci can provide highly informative polymorphic data for paternity testing, individual identification, and genetic population studies. A total of 20 autosomal short tandem repeat (STR) loci from 2220 unrelated healthy individuals of Han population living in the central area of Yunnan province, Southwest China were amplified with the PowerPlex® 21 System. After Hardy-Weinberg equilibrium examination, the allele frequencies and forensic statistical parameters of 20 STR loci were evaluated. A total of 298 alleles and 1225 genotypes were observed for all the 20 loci. The allele frequencies varied from 0.0002 to 0.5130. The combined power of discrimination and the combined probability of exclusion of all 20 STR loci were 0.99999999521565 and 0.999999999999999999999999637, respectively. Meanwhile, genetic distances between Central Yunnan Han and 17 previously published populations were compared and a neighbor-joining (NJ) phylogenetic tree was developed and visualized by using MEGA 7 based on Nei’s standard genetic distance. The results demonstrated that these loci were highly polymorphic in the Han nationality in Central Yunnan, Southwest China and could be applied in forensic medicine and population genetics.