Molecular Markers for Population Studies of Cornus sanguniea

Cornus sanguinea is 4–5 m tall shrub and is distributed almost over the entire European continent and in some locations in Asia. The species can form hedges and grows along forest edges, riversides, and in floodplain forests. Cornus sanguinea occupies lowlands and terrain up to 1500 m in the Alps, and is often planted as an ornamental. To address some conservation issues with the species, genetic variation in natural populations has been assessed using isozymes and chloroplast markers. In these studies, genetic diversity was found to be relatively low compared to other tree species because of clonal reproduction.  A more robust genetic marker system was needed to evaluate both large- and small-scale genetic diversity and differentiation.  We developed microsatellite markers for the species from a small-insert GT- genomic library. Sixteen primer pairs were identified and optimized to amplify loci in 29 C. sanguinea individuals collected from nine populations in Germany and all loci were polymorphic. There were 5 to 16 alleles discovered per locus; H_O ranged from 0.00 to 1.00, and H_E ranged from 0.65 to 0.90. Tests of Hardy-Weinberg equilibrium were not conducted due to the small sample size and because plants often reproduce vegetatively. Understanding the extent of seed dispersal, genetic drift and and how selection operates will require knowledge of population structure. Although we had only a limited number of samples in our study, the 16 polymorphic microsatellites will be sufficient for the population genetics studies underway in Germany and assessing the extent of clonal reproduction in C. sanguinea.