Background. Licorice (Glycyrrhiza spp. L.) is used as a natural sweetener and medicinal herb. Molecular studies have been conducted to find differences between wild and cultivated species because most wild species are highly resistant to abiotic and biotic stresses compared with their cultivated counterparts. However, few molecular markers have been developed for studying the genetic diversity and population structure of licorice species and to identify differences between cultivars. Thus, the present study aimed to develop a set of genomic simple sequence repeat (SSR) markers for molecular studies of these species.
Methods. We designed 100 SSR markers based on the whole-genome sequence data of wild Glycyrrhiza lepidota and selected 62 SSR markers.
Results. The genetic diversity analysis using these markers identified 2–23 alleles, and the major allele frequency, observed heterozygosity, genetic diversity, and polymorphism information content were 0.11–0.91, 0–0.90, 0.17–0.94, and 0.15–0.93, respectively. Interspecies transferability values were 93.5%, 91.6%, and 91.1% for G. echinata, G. glabra, and G. uralensis, respectively. Phylogenetic analysis clustered cultivated (group 1) and wild (group 2) species into three and two subgroups, respectively. The SSR markers developed here can be applied to genetic diversity, population structure, and cultivar differentiation studies, as well as to breeding of licorice varieties.