Artificial defloration and furanocoumarin induction inPastinaca sativa (Umbelliferae).

Damage simulating herbivory was tested as an inducer of furanocoumarins in the floral parts of the wild parsnip,Pastinaca sativa (Umbelliferae). In one experiment, primary umbels ofP. sativa were partially deflorated over the course of nine days, and higher-order umbels as well as the remaining primary umbel floral parts were sampled. Total furanocoumarin concentration was not significantly affected by defloration, but one furanocoumarin, isopimpinellin, increased in one floral stage of the secondary umbel in damaged plants. In a second experiment, primary umbels were completely deflorated and the higher-order umbels allowed to set seed. No significant effect of defloration on furanocoumarin content was found in the seeds of the higher-order umbels.