Genetic diversity of the resource insect Schlechtendalia chinensis (Homoptera:Pemphigidae) populations in China based on AFLP analysis

The genetic diversity and genetic structure of six populations (totally 102 individuals) of the resource insect Schlechtendalia chinensis in China were examined using amplified fragment length polymorphism (AFLP) method in order to provide molecular evidence for proper utilization and protection of this economic insect. Four pairs of selective primers were used to amplify the total DNA of S. chinensis samples with AFLP method. The results indicated that the primers yielded a total of 126 scorable loci, of which 100% was polymorphic. The percentage of polymorphic loci in different populations changed from 23.81% to 66.67%, Nei’s gene diversity index (H) from 0.0942 to 0.1980, and Shannon’s index (I) from 0.1381 to 0.3027. AMOVA analysis showed that 57.99% genetic variation came from intra-populations, 42.41% genetic variation from inter-populations, and the overall Fst was 0.4242. NJ cluster analysis showed that the six populations are grouped into two major clades (A and B), each consisting of three populations. Clade A includes three populations (Yangque, Danzhai and Hanzhong), and clade B includes the other three populations (Anxian, Zhushan and Longsheng). The results suggest that the genetic diversity of S.chinensis populations is low, but the genetic differentiation among populations is high. The genetic diversity among populations is not related to the geographic distance (P0.05).