This study was conducted to determine the effects of light intensity on the growth and development as well as the anthocyanin content of two Echeveria species, namely Echeveria agavoides and E. marcus. Three light intensity levels (high, 150 μmol･m-2s-1; intermediate, 75 μmol･m-2s-1; and low, 35 μmol･m-2s-1) served as the treatments, which were replicated four times. The results revealed that the tallest and largest plants were those under low light conditions. It was observed that there was a decline as the light intensity increased, which is attributed to the coping mechanisms of plants to search for light sources, which has a similar effect to bolting or an increase in the node-to-node distance. CIELAB color values of L* and a* for both species were significantly affected by the light intensity, indicating changes in the lightness of hue and green-to-red color pigmentation in plants. These results were strongly reflected in those of the anthocyanin content analysis, where a direct increase in the concentration was observed with increasing light intensity. The results of the anthocyanin analysis were also supported by the histogram, smart segmentation images, as well as the ratio of red and green pigments found in the images. Thus, a high light intensity should be used to increase the quality and provide conducive growing conditions for both succulent species.

This study was performed to investigate how changing the period of light and dark influences the vegetative growth and the photosynthesis of Doritaenopsis Queen Beer ‘Mantefon’. Clones of Dtps. Queen Beer ‘Mantefon’ at 4-month-old stage were grown in a closed-plant factory system with four different light/dark cycles; 06/06 h, 08/08 h, 10/10 h, and 12/12 h. Temperature and relative humidity were set at 28oC and 80%, respectively, with a photosynthetic photon flux density of 160 ± 10 μmol·m-2·s-1. Repetitive measurements showed that the leaf length and the leaf width were the longest under 12/12 h closely followed by 10/10 h. The fresh weight and the dry weight of leaves and roots were the heaviest at 10/10 h treated samples. Different CO2 uptake patterns were observed from different light/dark cycles. Under 10/10 h and 12/12 h treatments, the CO2 uptake started at early dark period. When the light/dark cycles were shortened to 06/06 h and 08/08 h, the CO2 uptake started at the middle of dark period. Total CO2 uptake amounts were the highest under 12/12 h treatment followed by 10/10 h, 06/06 h, and 08/08 h treatments. Quantitative measurements showed that the vegetative growths under 10/10 h treatment were comparable with that of 12/12 h treatment. These studies indicated that manipulating light/dark can modify the photosynthesis patterns and vegetative growth of Dtps. Queen Beer ‘Mantefon’, resulting in the reduction of the production period.

C3식물과 CAM식물에 광량을 달리 처리하여 음이온 발생량을 조사하였다. C3식물은 0, 20, 100, 200(µmol·m-2·s-1)의 광량이 주어졌으며, CAM 식물에는 주간과 야간에 음이온 발생량을 측정하였다. C3식물의 광량별 음이온 발생량은 관음죽(300/cm3), 팔손이나무(497/cm3), 로즈마리(735/cm3) 3종 모두 20µmol·m-2·s-1에서 가장 높게 나타났으며, 20µmol·m-2·s-1이상의 광량에서는 감소하는 경향을 보였다. CAM 식물의 음이온 발생은 주간과 야간에 비슷하게 양이 발생하였으며, C3 식물에 비해 매우 적은 양이 발생하였다. CAM 식물 중에 음이온 발생량은 금전수가 가장 많고, 산세베리아가 가장 적었다. 결과적으로 C3 식물의 음이온 발생량은 20µmol·m-2·s-1 에서 가장 많았으며, CAM 식물의 음이온 발생량은 C3 식물에 비해 매우 적고, 주간과 야간에 비슷한 양이 발생하였다.