Polymorphic chloroplast simple sequence repeat primers for systematic and population studies in the genus Hordeum

In this study we report the development of primers to amplify polymorphic chloroplast simple sequence repeats in the genus Hordeum, which includes cultivated barley (H. vulgare ssp. vulgare) and its wild progenitor H. vulgare ssp. spontaneum. Polymorphic products were amplified in a wide range of Hordeum spp. and intraspecific variation was detected in both cultivated and wild barley. A decrease in cytoplasmic diversity was observed between sspp. spontaneum and vulgare as well as between ssp. vulgare landraces and cultivars, which is characteristic of domestication processes in many crop species. We also observed possible evidence for reticulate evolution of H. brachyantherum polyploids, with apparent multiple cytoplasmic introgressions during successive polyploidization events.