UV-light effect on the leaf pigmentation of Cotinus coggygria 'Royal Purple'

Cotinus coggygria cv. Royal Purple leaves change color from green to a dark wine-purple in response to high light intensities and low temperatures. In the present study, we examined the effect of UV light (300-400 nm) on pigmentation of C. coggygria leaves. The UV effect was examined by covering plants with three different polyethylene sheets that transmit different amounts of UV light. Since Cotinus are often grown under plastic covers, our work will determine the spectral properties of covers that will give the maximal anthocyanin pigmentation in leaves. We show that the UV light between 300-400 nm is crucial for accumulation of pigments in Cotinus foliage. Low temperatures, have no effect on the pigmentation if the plants are not exposed to UV light as well. (C) 1997 Elsevier Science B.V.