Genetic diversity assessment of Guangling Large-Tail sheep and introduced breeds in Shanxi Province using microsatellite markers and inference of heterosis potential

This study was designed to assess the genetic diversity and population genetic structure of five sheep breeds in Shanxi Province, China, and to infer the heterosis potential based on their genetic relationships using 20 genome-wide microsatellite markers. Our analysis focused on the local Guangling Large Tail Sheep (GLLTS) breed and four introduced breeds: Hu Sheep (HS), Oula Tibetan Sheep (OLTS), Texel Sheep (TS), and Small Tail Han Sheep (STHLS). The results demonstrated that all microsatellite loci exhibited high levels of polymorphism, making them suitable for evaluating genetic diversity. The genetic parameters indicating that the five populations possess substantial genetic diversity. The genetic variation index (Fst) results among the five populations showed that moderate differentiation between populations. The genetic structure analysis results and the UPGMA clustering diagram were largely consistent. TS exhibited a distant genetic relationship with the other breeds, while HS and GLLTS shared the closest genetic relationship. Based on these genetic evidences, crossing GLLTS with TS or STHLS could potentially achieve a greater degree of heterosis. These research findings provide a molecular genetic foundation for analyzing the genetic diversity of sheep in Shanxi Province and offer guidance for hybrid breeding programs aimed at optimizing breed performance and resource conservation.