Characterization of microsatellite loci in Castilleja sessiliflora and transferability to 24 Castilleja species (Orobanchaceae)(1)

• Premise of the study: Microsatellite primers were developed in the hemiparasitic perennial forb Castilleja sessiliflora to investigate patterns of gene flow and genetic diversity within and among populations. • Methods and Results: Twelve polymorphic loci were identified in C. sessiliflora and tested on three populations (32 individuals each) sampled across the range of the species. The loci amplified di- and trinucleotide repeats with 3–14 alleles per locus. To assess cross-amplification, primer pairs were also tested on 24 additional Castilleja species that represent the morphological and geographic diversity of the genus. We provide reports of their effectiveness in all 25 taxa. • Conclusions: These results indicate the utility of these primers in C. sessiliflora for future studies of genetic structure and gene flow, as well as their widespread applicability in other members of the diverse and complex genus Castilleja.