Microsatellite DNA and Its Application in Mentha Species

Essential oil plants in Mentha species have been valued historically for their medicinal, culinary, and fragrance properties. Despite the existence of several mint species and many cultivars, the U.S. Mint Oil Industry is based upon three sterile clones and their minor somatic variants. The narrow genetic base of these commercial varieties could endanger the stability of the mint industry if virulence of disease and/or large-scale fluctuations in weather occur. Extensive genetic diversity exists among other mint species and the U.S. mint industry is considering more effective future exploitation of this diversity to broaden the genetic base. Unfortunately, genetic diversity in mint is very poorly characterized, and the genetic relationships among known species and cultivars remain obscure. Here, we propose evaluating the utility of simple-sequence repeat (SSR or microsatellite) DNA fingerprinting techniques for answering the following questions: What are the relative levels of genetic diversity in extent mint species and cultivars? What are the genetic relationships among those species and cultivars? How well do SSR markers discriminate among closely related cultivars?