Hybrids between wild and cultivated carrots in Danish carrotfields

It is well known that wild carrots may pollute the seed cropsof cultivated carrots, but whether cultivated carrots can alsodisperse pollen and seed, and thereby introduce genes into wildcarrot populations, is only little described. In Denmark, there is nocommercial seed production of carrots, and as biennials they shouldnormally not flower before harvest of the roots. Still, floweringindividuals can be found in most Danish fields, and sometimes in veryhigh numbers. At least 75% of the flowering plants are malefertile, with ca. 83% of the pollen being viable. More thanhalf of the plants produce seeds. Pollen and seed dispersal fromfields into wild carrot populations is probably rather frequent inDenmark. A closer inspection of the morphology of flowering plantsindicate that some of these (2–60%) arebolters of pure cultivar origin, as indicated primarily by orangeroot colour. The remainder is probably first or advanced generationhybrids between wild and cultivated plants, as indicated by theirwhite roots and combinations of morphological characters from eitherplant type. Some of these hybrids are imported to Denmark togetherwith the sowing seed, as indicated by significantly differentfrequencies of bolters with white roots in different carrot cultivarstested in the field.