Approach towards the control of rose flower opening by light environment

Abstract

The fact that plants bloom in rhythmic patterns has been widely known since ancient times.1 Morning glories (Ipomoea nil), for example, open in a synchronized fashion once a set amount of time passes after dusk (the beginning of the dark period). This means that, although morning glories open at dawn in early summer when it is light late into the evening, they begin opening at night in early autumn when it gets dark earlier in the evening. Meanwhile, rose petals develop only for a set period of time after dawn, after which the bud’s development is halted until the next morning.2 Our research has shown that this rhythmic growth of rose petals can be observed even in cut flowers, and it is affected by day length and the wavelength of the light.3 By uncovering the relationship between this rhythmic petal growth and light stimuli, thus deepening our understanding of the mechanisms of petal development, we can pave the way for new technical advances in regulating flower opening through light environmental control. Here we discuss the relationship between rhythmic petal development in cut roses and light stimuli, as well as approaches for controlling light-dependent petal development.