Development of microsatellite markers for, and a preliminary population genetic analysis of, the white-backed planthopper.

For a better understanding of the population structure and dispersal rates of Sogatella furcifera, we developed 21 novel polymorphic expressed sequence tags (EST) derived microsatellites, which were successfully amplified in four multiplex polymerase chain reaction sets. These new microsatellites were firstly assessed in 20 individuals sampled from Wenshan in China. The results showed that all 21 loci were highly polymorphic; the number of alleles ranged from 3 to 9, with an average of 4.8 alleles per locus. The observed and expected heterozygosity ranged from 0.200 to 0.900 and from 0.184 to 0.799, respectively. Nineteen of the 21 microsatellites without null allele, were subsequently used for population genetic structure analyses of five S. furcifera populations sampled in south region of China (sites up to 1314 kilometers apart). The observed and expected heterozygosity for each population ranged from 0.436 to 0.494 and from 0.454 to 0.482, respectively. The level of population differentiation was very low, with an average pairwise F ST of 0.002. Bayesian cluster analysis result suggested that the five S. furcifera populations formed one genetic cluster. Discriminant analysis of principle components detected three genetic clusters. The spread of the three clusters across the five populations explained the lack of population differentiation and the Bayesian cluster result. All the results indicated that long-distance migration of this pest allowed genetic mixing between populations from remote geographical origins. These new microsatellites will be powerful tools for population genetics studies of S. furcifera.