Red light stimulates flowering and anthocyanin biosynthesis in American cranberry

Morphological responses of American cranberry (Vaccinium macrocarpon Ait, Ericaceae) to different light conditions (red, far-red, white light and sunlight) were examined. Root growth and development, stem elongation, leaf enlargement, de-etiolation of stem and leaf, flower bud formation, and flowering of American cranberry were measured under each light condition and in the dark. It was found that red light promotes development of roots and leaves, flowering, and de-etiolation of stem and leaf of American cranberry. Stem elongation and etiolation of stem and leaf were shown in far-red light and dark. Anthocyanin biosynthesis as phytochemical response in cranberry plants was most sensitive to red light. Estimation of anthocyanin levels in different parts of cranberry plant suggested that anthocyanins were present only in red fruit skins, and not in peeled fruits, green fruits, green leaves, green stems, roots and seeds.