Hybrids between wild and cultivated carrots in Danish carrot fields

It is well known that wild carrots may pollute the seed crops of cultivated carrots, but whether cultivated carrots can also disperse pollen and seed, and thereby introduce genes into wild carrot populations, is only little d escribed. In Denmark, there is no commercial seed production of carrots, an d as biennials they should normally not flower before harvest of the roots. Still, flowering individuals can be found in most Danish fields, and somet imes in very high numbers. At least 75% of the flowering plants are male fe rtile, with ca. 83% of the pollen being viable. More than half of the plant s produce seeds. Pollen and seed dispersal from fields into wild carrot pop ulations is probably rather frequent in Denmark. A closer inspection of the morphology of flowering plants indicate that some of these (2-60%) are bol ters of pure cultivar origin, as indicated primarily by orange root colour. The remainder is probably first or advanced generation hybrids between wil d and cultivated plants, as indicated by their white roots and combinations of morphological characters from either plant type. Some of these hybrids are imported to Denmark together with the sowing seed, as indicated by sign ificantly different frequencies of bolters with white roots in different ca rrot cultivars tested in the field.