Biologists Explain Genetic Origins of Saffron Crocus

Saffron crocus (Crocus sativus) is the source of the most expensive spice in the world, with prices going up to 30,000 euros per kilogram. This spice whose aroma comes from apocarotenoid Safranal is produced from manually harvested stigmas, yet, despite its economic importance, its genome and chromosomes are poorly studied.

Researchers in Technische Universität Dresden (TUD) found that saffron crocus is a triploid hybrid species, is sterile, and cannot be bred. Although it has been cultivated for more than 3,500 years, all plants cultivated worldwide come only from daughter bulbs. For almost 100 years, there has been controversy as to the possible parent species of the saffron crocus.

The TUD researchers managed to look into the origins of the saffron crocus and shed light on the parent species using molecular and cytogenetic methods. In a paper published in New Phytologist, they report the autotriploid nature of saffron as a hybrid of wild Crocus cartwrightianus cytotypes.

Saffron crocus descended from the wild species Crocus cartwrightianus found in Greece. Through the genome sequencing of Saffron crocus and comparative chromosome analysis of different crocus species, the biologists were able to demonstrate that genomes of two Crocus cartwrightianus individuals with slight chromosomal differences are fused. These findings conclude the centuries-long search for the origins of this mythical plant.

For more details, read the TUD press release.