The origin of Saffron (Crocus sativus)

The saffron crocus, Crocus sativus, is a male-sterile triploid that ever since its origin has been propagated vegetatively by replanting the subterranean daughter corms. Its mode of evolution and area of origin are matters of intense and long-lasting debates. Here we provide evidence that diploid Crocus cartwrightianus, a species occurring in southern mainland Greece and on Aegean Islands, is the sole progenitor of the saffron crocus. Phylogenetic analyses of nuclear and chloroplast genes and genome-wide DNA polymorphisms indicate that saffron is genetically most similar to the Attic C. cartwrightianus populations. Based on our data we postulate that C. sativus is an autotriploid that originated in southern Attica by combining two different genotypes of C. cartwrightianus.