Genetic Diversity of Five Pelodiscus sinensis Sub-Populations in the Dongting Lake Basin Based on Cytb and 12S rRNA Markers

To explore the current state of genetic diversity of in the Chinese soft-shelled turtle (Pelodiscus sinensis) in the Dongting Lake basin, the genetic diversity of five sub-populations consisting of 71 turtles were analyzed through mitochondrial Cytb and 12S rRNA. Our results revealed 13 haplotypes for Cytb and 6 for 12S rRNA. The overall haplotype diversity and nucleotide diversity indices were 0.750 and 0.014, and 0.712 and 0.009, respectively. The Shaoyang sub-population showed the lowest genetic diversity according to both markers. The genetic distances between sub-populations ranged from 0.010 to 0.018 (Cytb), and from 0.002 to 0.014 (12S rRNA), with the largest distance observed between the Shaoyang and Junshan sub-populations. The Junshan sub-population was significantly different from the other sub-populations (p < 0.05), and gene exchange was weak, despite belonging to the same population. Genetic variation within the P. sinensis sub-population was much higher than that between sub-populations. There was no recent expansion event in the history of P. sinensis. Overall, the genetic diversity of P. sinensis was high, whereas it appeared to be homogenous, suggesting a potential decline in genetic diversity. This study provides valuable insights for the conservation and sustainable use of P. sinensis.