Senescence-associated Gene Expression in Narcissus ‘dutch Master’

Flower senescence is a highly controlled developmental event that culminates in the death of the floral organs. Most research on flower senescence has focused on the perianth, since it typically determines the commercial life of the flower. The mechanism by which the perianth dies differs between species: in some flowers, wilting is the primary symptom of senescence whereas in others, the perianth is shed prior to, or at the time of wilting. Daffodils (Narcissus) are widely grown commercial flowers that are prized for their beauty in spring. The flowers are short-lived and are reported to senesce independently of ethylene action (Woltering and van Doorn, 1988). In addition to the petals and sepals (tepals), daffodil flowers are unique in possessing an additional petaloid structure, the corona. We have used the flowers of the ‘Dutch Master’ cultivar as an experimental model to examine molecular changes associated with the onset of nonclimacteric flower senescence, and report here our preliminary results.