Isolation and characterization of microsatellite markers for the cleistogamous species Lamium amplexicaule (Lamiaceae)1

• Premise of the study: Lamium amplexicaule is a cleistogamous plant that produces both closed flowers (obligately self-pollinated) and open flowers (potentially outcrossed). The conditions for the maintenance of such a mating system depend on the outcrossing rate of the open flowers, which can be estimated using neutral microsatellite markers. • Methods and Results: Forty primer pairs corresponding to microsatellite motifs obtained by coupling multiplex microsatellite enrichment and next-generation sequencing were tested. Thirteen primers amplified with satisfying results. The polymorphism of these markers was studied in four French populations. Allele number varied from one to eight per locus and per population. Heterozygosity levels were significantly lower than those expected under Hardy–Weinberg equilibrium. • Conclusions: Our results are consistent with a partial self-fertilization pattern. These markers will be used to estimate the outcrossing rate as well as population differentiation in L. amplexicaule.