Subtracted Diversity Array identifies novel molecular markers including retrotransposons for fingerprinting Echinacea species

Echinacea, native to the Canadian prairies and the prairie states of the United States, has a long tradition as a folk medicine for the Native Americans. Currently, Echinacea are among the top 10 selling herbal medicines in the U.S. and Europe, due to increasing popularity for the treatment of common cold and ability to stimulate the immune system. However, the genetic relationships within the species of this genus are unclear, which makes difficult the authentication of the species used for the medicinal industry. We report the construction of a novel Subtracted Diversity Array (SDA) for Echinacea species and demonstrate the potential of this array for isolating highly polymorphic sequences.