Flowering and morphogenesis of chrysanthemum and kalanchoe in response to quality and intensity of night interruption light

다국어 초록 (Multilingual Abstract)

Both chrysanthemum and kalanchoe are qualitative short day plants (SDP), and they will not produce flowers when the night length is short than their critical values which is species- and cultivar-dependent. Flowering is effectively inhibited when the required uninterrupted night period is broken by short periods of exposure to night interruption light (NIL). Effect of quality and intensity of NIL on morphogenesis and flowering of chrysanthemum (Dendranthema grandiflorum) ‘Golden Egg’ and ‘Pearl Egg’ and kalanchoe (Kalanchoe blossfeldiana) ‘Lipstick’ and ‘Spain’ were examined. Plants were grown in a close-type plant factory under a light intensity of 250 μmol·m-2·s-1 PPFD provided by white light emitting diodes (LEDs) under an either long day (LD, 16-h light period + 8-h dark period), short day (SD, 8-h light period + 16-h dark period), or SD with a 4-h night interruption (SD + NI) condition. The NI was provided by 10 or 20 μmol·m-2·s-1 PPFD provided by either blue (B), red (R), white (W), or blue+white (BW) LEDs. In chrysanthemum ‘Golden Egg’, most of the growth parameters were more affected by light quality than light intensity of NIL. In chrysanthemum ‘Pearl Egg’, leaf area, and fresh and dry weights of the root were affected by quality of NIL, while it was not affected by intensity of NIL. In the kalanchoe ‘Spain’, SPAD value and morphogenic characteristics, such as leaf length, leaf width, leaf area, leaf thickness and fresh and dry weights of the shoot and root, were affected by quality of NIL, while those of ‘Lipstick’ were not significantly affected by NIL. Plant length of chrysanthemum was the greatest in the LD, while that of kalanchoe was the greatest in the SD. Number of leaves per plant of chrysanthemum was less in the SD and NI-B provided at 10 μmol·m-2·s-1 PPFD than other treatments, while that of kalanchoe was significantly less in the SD than in other treatments. In chrysanthemum, flowering was observed in the SD treatment and NI-B provided both at 10 or 20 μmol·m-2·s-1 PPFD. In the case of kalanchoe, flowering of ‘Lipstick’ was not affected by quality of NIL, ‘Spain’ flowered in the SD and NI-B provided at 10 μmol·m-2·s-1 PPFD. It is thought that flowering response to quality of NIL depends on cultivar of kalanchoe. These results suggest that morphogenesis and flowering of these plants were affected by quality and intensity of NIL. The results of this study suggest that effect of quality and intensity of NIL on morphogenesis and flowering was consistent in chrysanthemum, but differed in kalanchoe, by cultivar. There is need to assess further effect of quality and intensity of NIL on morphogenesis and flowering in SDPs before practical applications.

목차 (Table of Contents)

• Ⅰ. INTRODUCTION 2
• Ⅱ. LITERATURE REVIEW 3
• Ⅲ. MATERIALS AND METHODS 7
• Ⅳ. RESULTS AND DISCUSSION 13
• 1. Effect of Quality and Intensity of Night Interruption Light from LEDs on Flowering and Morphogenesis of Chrysanthemum Cultivars 13
• 2. Effect of Quality and Intensity of Night Interruption Light from LEDs on Flowering and Morphogenesis of Kalanchoe Cultivars 35
• Ⅴ. CONCLUSIONS 58
• Ⅵ. ABSTRACT in Korean 59