RESPIRATION AND ETHYLENE EVOLUTION IN RELATION TO FLOWER BUD ABSCISSION IN ASIATIC HYBRID LILY

To investigate possible mechanisms involved in bud abscission in the Asiatic hybrid lilies Lilium elegans Thunb., ‘Red Carpet’ and ‘Sunray’, respiration, C₂H₄ production, and soluble sucrose, glucose, and fructose were analyzed in flower buds.
Respiration decreased from 480 to 200 mg CO₂/kg hr in ‘Red Carpet’ and from 300 to 200 mg CO₂/kg hr in ‘Sunray’ as bud length increased from 1.8 to 6.5 cm.
Buds smaller than 2.6 cm in length failed to open and produced a transient CO₂ peak 81 hours after an initial rapid respiratory decline after harvest.
A peak in C₂H₄ production occurred concomitantly with the CO₂ peak.
Buds longer than 4.8 cm opened without undergoing a rise in CO₂ and C₂H₄ evolution.
When bud abscission was induced by heat treatment, sucrose content decreased from 2.91 to 0.64 mg/g fw in ‘Red Carpet’ and from 3.42 to 0.43 mg/g fw in ‘Sunray’. The high respiration rate in concert with the diminished sucrose content in small buds suggests that bud abscission may involve depletion of the soluble carbon source necessary for energy production and metabolism for proper development.

V International Symposium on Flower Bulbs

Mark S. Roh

https://doi.org/10.17660/ActaHortic.1990.266.16