Regulation of flower development and anthocyanin accumulation in Gerbera hybrida

Anthocyanin accumulation increased with pigmentation during flower growth in Gerbera hybrida. Light is important for both anthocyanin accumulation and flower growth. When inflorescences were shaded with aluminium foil in vivo at the developmental stage 1., 2 or 3, both anthocyanin accumulation and inflorescence growth were dramatically inhibited. The inhibitory effect was not reversed when the shading was removed and the inflorescences were re-exposed to light at later stages. At developmental stages 4 and 5, dark treatment had no significant effect on flower development and pigmentation. Similar results on anthocyanin accumulation were obtained when inflorescences and outermost ray florets (rf) were detached at stage 2 and cultured in vitro with 3% sucrose in the medium. Therefore, Gerbera hybrida flowers were sensitive to photoregulation during early developmental stages, especially stages I and 2. Moreover, in vitro photoregulation of flower growth including inflorescence fresh weight and rf length were different from those in vivo, indicating some substances transported from plant seedlings could be required in photoregulation. Our statistical analysis has suggested that anthocyanin accumulation is closely correlated with flower development during in vivo photoregulation.