Population Genetics of Haliotis discus hannai in China Inferred Through EST-SSR Markers

The Pacific abalone Haliotis discus hannai originated in cold waters and is an economically important aquaculture shellfish in China. Our goal was to clarify the current status of the genetic structure of Pacific abalone in China.

In this study, eighteen polymorphic EST-SSR loci were successfully developed based on the hemolymph transcriptome data of Pacific abalone, and thirteen highly polymorphic EST-SSR loci were selected for the genetic variation analysis of the six populations collected.

The results showed that the average number of observed alleles was 8.0769 (RC)-11.3848 (DQ) in each population. The number of observed alleles in the DQ, NH, and TJ populations was significantly higher than that in the RC population. The cultivated population outside the Changshan Islands has experienced a 22.79% reduction in allele diversity compared to the wild population of DQ. The pairwise F_st values and analysis of molecular variance (AMOVA) revealed significant population differentiation among all populations except DQ and NH populations, with RC and ZZ cultured populations exhibiting the largest population differentiation (F_st = 0.1334). The phylogenetic tree and structural analysis divided the six populations into two groups (group 1: NH, DQ, and ZZ; group 2: DL, TJ, and RC), and there was no relationship between geographical distance and genetic distance.

These results may reflect the large-scale culture from different populations in China and the exchange of juveniles between hatcheries. Different breeding conditions have led to a higher degree of genetic differentiation between the RC and ZZ populations. This study enables a better understanding of the genetic diversity and structure of current Pacific abalone populations.