Microsatellite Diversity of Dalmatian sage Populations from the Balkan and Apennine Peninsula

Dalmatian sage (Salvia officinalis L., Lamiaceae) is a well-known aromatic and medicinal Mediterranean plant that is native in coastal regions of the western Balkan and central and southern Apennine Peninsulas and is commonly cultivated worldwide. We used eight microsatellite markers to investigate genetic diversity and population structure. A total of 1, 350 specimens from 50 locations across the Balkan Peninsula as well as from 12 locations form the Apennine Peninsula were sampled and genotyped. The model-based structure analysis revealed the presence of five geographically coherent genetic clusters that differed significantly in allelic richness, observed and expected heterozygosity. The highest level of allelic richness was found in populations located in the central part of the eastern Adriatic coast, while decreases in allelic richness were evident towards the northwestern Adriatic coast and southern and eastern regions of the Balkan Peninsula. Populations from Apennine Peninsula had substantially lower allelic richness than those from balkan Peninsula. The genetic relationships among the genetic clusters were evaluated based on net nucleotide distance. A Neighbor–Joining tree based on the net nucleotide distances was generated showing that the two Apennine clusters were markedly divergent from each other as well as from the three Balkan clusters suggesting their long-term genetic isolation that lead to a reduction in gene diversity.