Effects of temperature and shade treatment on flower colors and characteristics in newly established reddish-purple tuberose (Polianthes)

Effects of temperature and light condition on flower colors and flowering characteristics of newly established reddish-purple flowered tuberose '77A05' were investigated. Days to anthesis from planting of corms at 20 °C were significantly longer than at 25 or 30 °C. Floret diameter and petal length was significantly larger at 30 °C than at 20 or 25 °C. Flower color was almost white at 30 °C, whereas the flowers cultivated at 20 °C showed reddish-purple. The flowers cultivated at 25 °C were almost white by 45% shading, but pale reddish-purple under 25 or 0% shade treatment. Anthocyanin content was extremely low at 30 °C. These results seem to relate to the enzyme activity which participate the biosynthesis of anthocyanins. Environmental conditions for the cultivation of the anthocyanin-containing hybrid tuberose must be carefully considered.