抄録
Hypocotyl elongation patterns investigated in seven major bedding plants, Impatiens walleriana, cv. ‘Tempo Red’, Antirrhinum majus, cv. ‘Floral Shower Deep Rose’, Leucanthemum puldosum, cv. ‘Snowland’, Zinnia, cv. ‘Profusion Cherry’, Matthiola incana, cv. ‘Kiss Me Salmon’, Catharanthus roseus, cv. ‘Bedesse Rose’, and Tagetes patula, cv. ‘Bonanza Yellow’. Seeds were sown in a 288-cell tray and germinated in a growth chamber maintained at 23°C, under 200 μmol m-2s-1 PPF and a 12-hour photoperiod (06:00 to 18:00) provided by fluorescent lamps. The seedlings grown under the same conditions. Hypocotyl elongation was measured using an image processing system in which CCD was mounted on a stepping motor. Ten images were captured simultaneously every 20 min utes few days period and stored in computer. Image analysis performed with a software developed in-house using “Visual Studio. Net”. It was observed that Impatiens grew remarkably between 10:00 and 14:00 during the light period. On the other hand, “Stock” had relatively unvaried elongation during the day and the night. Consequently, we concluded that the profiles of hypocotyl elongation vary between plant species. Normalized elongation for each photoperiod was calculated. Elongation during the light period was more than 70% for “Impatiens”, “Snapdragon”, “Chrysanthemum” and “Zinnia”. On the other hand, “Stock”, “Vinca” and “Marigold” characterized by more than 60% elongation during the dark period. Our results clearly indicate that hypocotyl elongation in the seven species studied can be classified into “light period elongation” type and “dark period elongation” type.
