Development of SSR markers for Carex curvula (Cyperaceae) and their importance in investigating the species genetic structure

Abstract

Microsatellite primers were developed and tested to genotype several populations of Carex curvula s. l. (Cyperaceae), in order to infer the phylogeographic relationships of the populations within species and the boundaries between the two described subspecies: C. curvula subsp. curvula and C. curvula subsp. rosae. Candidate microsatellite loci were isolated based on next-generation sequencing. We tested 18 markers for polymorphism and replicability in seven C. curvula s. l. populations and identified 13 polymorphic loci with dinucleotide repeats. Genotyping results showed the total number of alleles per locus varied from four to 23 (including both infrataxa), and the observed and expected heterozygosity ranged between 0.1 to 0.82 and 0.219 to 0.711, respectively. Furthermore, the NJ tree showed a clear separation between C. curvula subsp. curvula and C. curvula subsp. rosae. The development of these highly polymorphic markers proved to be very efficient not only in delineating between the two subspecies, but also in genetic discriminating at population level within each infrataxon. They are promising tools for evolutionary studies in Cariceae section, as well as in providing knowledge on patterns of the species phylogeography.