Abstract
A key step in regulating the flowering of Phalaenopsis is to control the emergence of the flower stalk or spiking. Light quality is an important factor to regulate plant reproduction. We used either red or blue light emitting diodes (LEDs) to substitute for 10% photosynthetic photon flux emitted by white fluorescent tubes as the control (WC) at approximately 70 μmole·m-2·s-1 to examine the effects of enhanced red (WR) or blue (WB) light on spiking and the dawn-to-dusk fluctuations in the photosynthetic pigments and carbohydrates of Phalaenopsis aphrodite, which were grown in 7.5 cm diameter pots for six weeks. WR treatment significantly elevated the ratio of red to far-red light and the level of phytochrome photostationary state in concurrence with an increase in the spiking ratio and length, but had little effect on the concentrations of chlorophyll a and chlorophyll b in the leaf, levels of soluble sugars such as glucose, fructose, sucrose, and insoluble starch in the leaf and shortened stem, the locus of spiking, when compared to the other two treatments. Evidently, the spiking of Phalaenopsis is improved by dependent on the relative amount of active phytochrome expressed in the photostationary state.
Highlights
Phalaenopsis orchids are popular and valuable potted ornamental plants worldwide for their beautiful and longlasting flowers that have a variety of shapes, sizes, and colors
The ratio of red to far-red in with supplemental red light (WR) was 12.19, significantly higher than for 3.63 and 4.03 in with supplemental blue light (WB) and were named control (WC), respectively (Table 1). These results clearly show that a slight increase in red supplement greatly elevated the level of photostationary state (PSS) and the R/FR ratio in WR compared to WB and WC
The magnitude of dawn-to-dusk starch biosynthesis in the leaf was slightly increased in WR, the contents of glucose, fructose, and sucrose in the leaf and stem, and starch in the stem did not show significant differences among the three treatments (Table 4)
Summary
Phalaenopsis orchids are popular and valuable potted ornamental plants worldwide for their beautiful and longlasting flowers that have a variety of shapes, sizes, and colors. Flowering time must be precisely scheduled to. (2016) Enhancing Flower Stalk Emergence in Phalaenopsis by Red Light Supplementation. American Journal of Plant Sciences, 7, 639-648. One of the key steps in regulating Phalaenopsis flowering is to control the emergence of the flower stalk or spiking. Phalaenopsis is a monopodial orchid with leaves alternating on each side of the plant and the bases of the leaves are connected to a shortened stem. One or 2 dormant flower stalk bud(s) emerges from the stem at the base of the third or fifth leaves that are numbered basipetally from the aerial portion of the plant [1]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
