Light-stimulated Ethylene Production by Germinating Cucumber Seeds1

The degree to which white light stimulated ethylene production in germinating seeds of cucumber ( Cucumis sativus L.) was influenced by the length of time the seed had been germinated in the dark before being exposed to light. Maximum stimulation occurred when 24 hour old dark-grown seedlings were exposed to 40 μ E m −2 sec −1 light for 24 hours. Ethylene production increased with the duration and intensity of light exposure at all seedling ages. Neither the light or dark rates of ethylene, or carbon dioxide production, nor their ratios, were highly correlated with the sexual phenotype of the 9 cultivars examined.