ISHS Acta Horticulturae 325: VI International Symposium on Flower Bulbs
HORMONAL CONTROL OF DORMANCY IN BULBLETS OF LILIUM SPECIOSUM CULTURED IN VITRO |
| Authors: | M.M. Gerrits, K.S. Kim, G.J. De Klerk |
| Abstract:
Bulblets of Lilium speciosum regenerated on scale explants in vitro provide an excellent system to study the development of dormancy. Here we report on the hormonal regulation of dormancy. Abscisic acid (ABA) added to the medium did not affect the dormancy status of regenerated bulblets. However, fluridone, an inhibitor of ABA synthesis, prevented the development of dormancy. The fluridone effect was reversed by simultaneous addition of ABA. These data indicate that ABA is required for the induction of dormancy but that a low dormancy level is not caused by a low level of endogenous ABA. Continuous synthesis of ABA was required for the maintenance of dormancy. Paclobutrazole (PP333), an inhibitor of GA synthesis, reduced the level of dormancy. A soak of dormant bulblets for 24 h in an aqueous solution of GA4+7 broke dormancy almost completely. However, in contrast to a cold treatment, the soak with GA4+7 did not result in a switch of the bulblet from source to sink. A soak in aqueous solutions of IBA or BAP had no effect. | |
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