Assessment of genetic diversity among wild populations of the striped catfish (Pangasianodon hypophthalmus) by 20 novel microsatellite markers.

Abstract

The striped catfish, Pangasianodon hypophthalmus, is one of the most economically important aquaculture species in Vietnam. This study developed 26 novel microsatellite markers from the draft genome of the striped catfish to assess the genetic diversity of three wild populations of the striped catfish (Bien Ho, Cuu Long, and Kratie) for establishing the breeding program. The study exhibited that 6 out of 26 loci had significantly high null allele frequency and deviated from Hardy - Weinberg equilibrium; thus, they were eliminated for further analysis. Across 20 loci without null alleles, a total of 255 different alleles was identified, ranging from 7 to 21 alleles per locus, with many unique alleles for each population. The results based on 20 loci revealed the mean polymorphic information content PIC=0.783; the mean observed heterozygosity Ho=0.809; the mean expected heterozygosity He=0.812; inbreeding coefficient Fis=-0.0147 (Fis<0). The results indicated that the striped catfish populations have high genetic diversity and are suitable for selective breeding. The Analysis of Molecular Variance (AMOVA) and comparison of genetic distances showed significant genetic differentiation among three populations while the Kratie population was distant from the others.