In Exp. 2 (see Section 2.3), the pedicel + ovary had grown by 1.4 cm after 3 d of storage in water at 3 °C. After storage in water for 11 d these parts had grown by 3 cm, compared with day 0 (data not shown). Compared to flowers that had not been stored, storage of flowers in water at 3 °C (in darkness) for 3 or 11 d did not affect the maximum length of the pedicel + ovary and did not influence maximum flower opening, during vase (data not shown). Dry storage at 3 °C or 1 °C, for 3 or 11 d, resulted in inhibited elongation of the pedicel + ovary and in less flower opening, during subsequent vase life at 20 °C (data not shown).
In Exp. 3, differences between one, two and three days of dry storage were investigated at 15 °C and 20 °C. During vase life the flowers opened after 1 day of dry storage at these temperatures but the opening was less than in the controls in water (Table 1). After two days of dry storage at 15 °C only 5 out of 10 flowers opened during vase life, while after this period of dry storage at 20 °C only 2 out of 10 opened. No flower opening was found during vase life after dry storage for 3 d (data not shown). The effects on opening were well correlated with those on pedicel + ovary length (data not shown).
Table 1.
Effects of 3 days of continuous darkness and 3 days of a 12 h dark/light cycle, on flower opening in cut Iris x hollandica cv. Blue Magic flowers, with a stem length of 45 cm and all leaves attached. At the onset of the experiment flowers either showed the tips of the tepals of the closed bud (mature buds) or were about to show the tips (immature buds). Flowers were in a climate-controlled room at 20 °C and 15 μmol m−2 s−1from Philips TDL 36 W/84 cool white fluorescent tubes, from 7 a.m. to 7 p.m., and either in a perspex chamber (RH about 99%) or outside the chamber (RH 60%). Two chambers were used, one in which the light of the climate-controlled room could enter from five sides, and one covered with black plastic (complete darkness). The degree of flower opening, expressed as the angle between tepal bases, and the length of pedicel + ovary were measured after 3 d of storage.