Development of microsatellites from Cornus mas L. (Cornaceae) and characterization of genetic diversity of cornelian cherries from China, central Europe, and the United States

Cornelian cherry (Cornus mas L.) is indigenous to central and southeastern Europe and is an ecologically and economically important shrub or small tree. The aim of this study was to develop molecular tools for assessing genetic diversity and provide unique molecular identification of C. mas samples from central Europe and United States. A microsatellite-enriched library was used to develop nine polymorphic microsatellite loci. The loci amplified perfect and imperfect repeats with 2 to 11 alleles detected per locus. Observed heterozygosity ranged from 0.00 to 0.71 and expected heterozygosity ranged from 0.00 to 0.82. Additionally, cross species transfer to Cornus eydeana was observed. The multilocus allelic data was used to cluster 37 C. mas samples and 1 C. eydeana sample based on the allele sharing distance matrix. The similarity coefficient ranged from 0.05 to 0.73 among all genotypes. All C. mas individuals clustered into two main clades, with the single C. eydeana sample used to root the dendrogram. All samples in group I belong to the botanical form Macrocarpa and originated from Austria, Poland, or Ukraine, whereas group II included samples that originated from Poland, Romania, and the United States. Five loci (CM007, CM010, CM031, CM037, and CM043) were used to develop a molecular identification key that successfully delineated all samples. The loci described in this study will facilitate further investigations of genetic diversity, gene flow, and genetic structure among populations of C. mas.