Subspecies variation of Daucus carota coastal (“gummifer”) morphotypes (Apiaceae) using genotyping-by-sequencing

The genus Daucus is widely distributed worldwide, but with a concentration of diversity in the Mediterranean Region. The D. carota complex presents the greatest taxonomic problems in the genus. We focus on a distinctive phenotypic group of coastal morphotypes of D. carota, strictly confined to the margins to within about 0.5 km of the Mediterranean Sea and the Atlantic Ocean, which we here refer to as coastal morphotypes or D. carota subsp. “gummifer” complex, the earliest name for taxa in this group. They are loosely morphologically coherent, sharing a relatively short stature, thick, broad, sometimes highly glossy leaf segments, and usually flat or convex fruiting umbels. We analyzed 288 accessions obtained from genebanks in England, France, and the USA, and an expedition to Spain in 2016, covering the Mediterranean and Atlantic coasts and Balearic Islands, where much of the gummifer complex variation occurs. Our study includes 112 accessions not examined before in this context. Genot...