Morphological characterization of a Daucus L. germplasm collection in Tunisia

The genus Daucus includes about 20 recognized species worldwide. Northern Africa represents a major center of diversity of Daucus, with Tunisia containing at least 12 species and six subspecies. We assessed morphological diversity from a Daucus L. germplasm collection of 103 accessions at the National Gene Bank of Tunisia. Previous investigation showed the effectiveness of fruit characters to identify several species and subspecies in the collection. However, distinction between wild carrot D. carota subsp. carota, cultivated carrot D. carota subsp. sativus (Hoffm.) Arcangeli and the morphologically similar species D. capillifolius was difficult. In order to further describe the collection and to resolve taxonomic classification between some Daucus species, we adopted here a descriptor list with 40 characters related to leaf, stem, flowering and inflorescence on a field collection of 17 accessions corresponding to the different species. Our results revealed significant differences between accessions for almost all characters. They will assist in future development of identification keys for Daucus species and subspecies in Tunisia.