First microsatellites developed from Spodoptera frugiperda and their potential use for population genetics

This is the first report of sequence-specific microsatellite markers (SSRs) of Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), an economically important pest of the American continent. We developed 178 microsatellite markers using pyrosequencing, and screened 15 individuals from 8 colonies collected from three geographical areas, Puerto Rico (PR), Texas (TX) and Mississippi (MS), including Bacillus thuringiensis (Bt) resistant and susceptible colonies. Cluster analysis was performed to determine the potential use of these SSRs in discriminating populations. SSR polymorphism grouped individuals of each colony together with a reliability of 100% estimated by bootstrap. In this analysis, colonies from TX grouped away from those from PR, but the two MS colonies grouped with TX and PR separately. Genetic distance between individuals of the same colony ranged between 0.22 and 0.56, whereas minimum genetic distance between colonies was 0.83. Unique pattern informative combination (UPIC) scores were calculated, and the 80 SSR markers that had UPIC scores of 1 or higher are listed according to their discriminating potential. UPIC scores allow choosing combinations of few highly informative markers for future studies. Heterozygosity of S. frugiperda individuals, estimated as the percentage of multiallelic loci based on 120 SSR markers, ranged between 35 and 59 %, with a difference of 2-15% between individuals of the same population. The markers reported here effectively identified the eight colonies of S. frugiperda tested. In addition, they could be used for monitoring migration of populations, in the development of biocontrol agents, in breeding programs, and for management practices in general.