Genetic diversity of the U.S. collection of Chinese hemlock Tsuga chinensis (Franch.) E. Pritz. based on simple sequence repeat markers

The Chinese hemlock, Tsuga chinensis (Franch.) E. Pritz., is becoming more well-known in U.S. landscapes as the native U.S. species ( T. canadensis (L.) Carr.) is under attack from the hemlock woolly adelgid. It is important to understand the genetic diversity and relatedness among accessions of T. chinensis to drive decisions about collections management, breeding methods, and forest or ecosystem management. We used SSR markers to evaluate the genetic diversity of 96 samples representing 35 accessions of Chinese hemlock held in collections in the U.S. Using 88 alleles from eleven SSR loci, we found high levels of diversity between and within accessions. Our results indicate that significant genetic diversity is available in the existing U.S. collections of T. chinensis , and, based on collection data, represents the wild gene pool well. This characterization of germplasm can be valuable in choosing accessions for use in horticultural and landscape applications or as part of a hemlock breeding program.