Leuciscus waleckii, an endemic fish species in the Yellow River Basin, holds significant ecological and germplasm value. However, its wild populations have declined sharply due to habitat destruction, overfishing, and environmental pollution, now surviving only in localized waters such as the upper Yellow River and the Luohe River system. To elucidate its germplasm characteristics and adaptive evolutionary mechanisms, we employed whole-genome resequencing to analyze 15 samples: 5 L. waleckii from the Luohe River system (LH group), 5 L. waleckii from the Wusuli River (WS group), and 5 L. waleckii from Dalai Lake in Inner Mongolia (ALK group, data downloaded from NCBI SRA database with accession number PRJNAXXXXXX). Analyses included SNP/InDel detection, genetic differentiation index (Fst), nucleotide polymorphism (θπ), and GO/KEGG enrichment. Results showed that the LH group exhibited the highest nucleotide polymorphism (θπ = 0.000998656), indicating optimal genetic diversity. Overall genetic differentiation among the three populations was low: Fst values between LH and WS, and between LH and ALK were 0.0402803 and 0.0370886, respectively (indicating minimal differentiation), while ALK and WS showed moderate differentiation (Fst = 0.0970577). UPGMA phylogenetic tree analysis confirmed that the Luohe River system L. waleckii forms an independent clade, distinct from the other two populations, verifying it as a separate species. This study provides insights into the adaptive evolution and germplasm potential of L. waleckii, offering a scientific basis for developing conservation strategies and sustainable utilization of this endangered species.
Zhao et al. (Tue,) studied this question.