Development of novel microsatellite markers for Alkanna tinctoria by comparative transcriptomics

Alkanna tinctoria (Boraginaceae) is an important medicinal herb with its main distribution across the Mediterranean region. To reveal its genetic variation and population structure, microsatellite markers were developed and validated in four Greek populations.

RNA-Seq data of the related species Arnebia euchroma and Echium plantagineum were assembled and mined to identify conserved ortholog sets containing simple sequence repeat motifs. Fifty potential loci were identified and then tested on A. tinctoria, of which 17 loci were polymorphic. The number of alleles ranged from one to nine, and the levels of observed and expected heterozygosity ranged from 0.000 to 1.000 and 0.000 to 0.820, respectively. Most of these loci could be successfully amplified in eight other species of Boraginaceae (Alkanna graeca, A. hellenica, A. sfikasiana, Echium vulgare, E. plantagineum, Lithospermum officinale, Borago officinalis, and Anchusa officinalis).

This study provides the first set of microsatellite loci for studying the genetic variation and population structure of A. tinctoria and shows their potential usefulness in other Boraginaceae species.