Analysis of light and sucrose potencies on petal coloration and pigmentation of lisianthus cultivars (in vitro)

To understand how the synthesis of petal pigments is influenced by light and sucrose, a cut flower culture was carried out with and without sucrose in the medium using different cultivars of lisianthus (Eustoma grandiflorum GRISE.). At low light intensity, lightness (L*) increased and chroma (C*) decreased. In the presence of sucrose, lightness (L*) decreased and chroma (C*) increased. Light intensity and sucrose exerted significant influences on the percentage distribution of different anthocyanidins and total anthocyanin in lisianthus flower petals. Flowers from detached buds cultured in sucrose containing media showed a significant increase in anthocyanin concentration in all the cultivars; 'Asuka no Asa', 'Mickey Rose' and 'Asuka no Kurenai' at a light intensity of 1400 to 2100 1x. Furthermore, more anthocyanin was produced in the sucrose media. The amount of anthocyanin in the petals increased gradually with thf: lengthening of the photoperiod, whereas flavonol content showed no significant variation in response to light intensity or photoperiod. We found that the lightness, chroma and petal color of the flowers were influenced by sucrose and light intensity through a change in total anthocyanin concentration in petals. The variation in Rower color caused by light and sucrose, determined on the basis of CIELAB color diagram, provides for a more accurate color notation in lisianthus. (C) 2001 Elsevier Science B.V. All rights reserved.