Genetic diversity and differentiation of three populations of Penaeus monodon Fabricus

Genetic diversity of two wild Penaeus monodon populations sampled from the coastal waters of Qinglan (Hainan Province of China, HN) and Malaysia (KD), and the F1 generation of a Thailand broodstock population (CP) were examined by vertical polyacrylamide gel electrophoresis. Of 21 loci encoded by ten enzymes, 11 were polymorphic. The mean proportions of polymorphic loci of HN, KD and CP were 36.36%, 45.45% and 50.00%, with the average heterozygosities of 0.135, 0.181 and 0.191, and the effective numbers of alleles per loci were 1.300, 1.330 and 1.329, respectively. The divergent indexes of HN, KD and CP were 0.023, 0.124, and 0.117, respectively. The genetic distance between the two wild populations was 0.005, and the gene differentiation coefficient was also very low (0.014). The results indicated that the F1 generation population had a higher genetic diversity than the two wild populations, and that the HN population had the lowest one. There was no significant differentiation between HN and KD populations and all populations existed with a slight heterozygote excess.