Genetic Diversity and Population Structure of a Pelagic Fish, Jack Mackerel (Trachurus japonicus), Based on AFLP Analysis

Trachurus japonicus is a commercially important species in the East Asia, especially in China, Japan and Korea. We estimated the gene flow among six populations of T. japonicus from Chinese and Japanese coastal waters by using amplified fragment length polymorphism (AFLP) technology. A total of 531 bands were amplified for 81 individuals of 6 populations by 4 pair selective primers, 89.27% of which were polymorphic bands. The population Miyazaki showed the highest Nei genetic diversity and Shannon genetic diversity. The topology of UPGMA tree was very shallow and no significant genealogical branches or clusters corresponding to sampling localities. The pairwise Fst between populations ranged from 0.016 to 0.107 and most were not significant after sequential Bonferroni correction. The results of AMOVA showed that 95.61% of genetic variation existed within populations and 4.39% existed among populations, which indicated low level of genetic differentiation among populations and high level of gene flow between populations. The results suggested that T. japonicus around distribution area should be considered to be a single panmictic population.