AFLP analysis of family level genetic diversity of shrimp Fenneropenaeus chinensis

Amplified fragment length polymorphism(AFLP)technique was used to detect the genetic variation among a total of 200 individuals representing 40 families.Popgene version 1.32,MEGA3.1 and AMOVA in Alequin 2.0 software were used for data analysis.Ten pairs of selective EcoRⅠ and MseⅠ primers produced 189 polymorphic markers out of total 307 bands amplified;the percentage of polymorphic loci was 61.56%.The percentages of polymorphic loci of the forty families were between 12.7% and 34.2%.Genetic diversity index of the families were between 0.049 4~0.122,and Shannon genetic diversity index were between 0.072 5 and 0.182(intra-family index was 0.197 5).AMOVA(Analysis of molecular variance)showed that a large proportion(52.87%)of genetic variation resided within families,while only a small proportion(47.13%)of genetic variation resided between families,representing an inter-family genetic differentiation index of Gst=0.471 3.Cluster analysis by UPGMA revealed the genetic distance and relationship between the 40 families,and the UPGMA dendrogram of the 200 individuals indicated that 90% of the individuals from each family could be fully clustered.Genetic diversity index G-based estimation revealed a low gene flow(Nm=0.560 9)among the 40 families.