The photosynthetic ability of in vitro plantlets (Fujiwara et al., 1987) can be improved by increasing the light intensity and CO2 concentration in the growth environment (Kozai et al., 1990). Light quality also plays an important role in photosynthesis, influencing the way in which light is absorbed by the chlorophyll. The light sources generally used for plant growth are fluorescent, metal halide, high-pressure sodium, and incandescent lamps. However, these sources contain unnecessary wavelengths that are of low quality for promoting growth.Recently, light-emitting diodes (LED) have been developed for accelerating plantlet growth. Their effects on chlorophyll synthesis (Tripathy and Brown, 1995), photosynthesis (Tennessen et al., 1994), and morphogenesis (Hoenecke et al., 1992) have been studied in a variety of plants. Compared with traditional lamps, the improved features of the LED include smaller mass and volume, as well as a longer life (Bula et al., 1991;Brown et al., 1995).Light intensity (PPF) greatly affects photosynthesis, respiration, and morphology of Rehmannia glutinosa plantlets (Cui et al., 2000;Seon et al., 2000). However, no reports are available about the effect of light quality on growth of this species. The objective of our study was to determine how growth parameters of R. The single node cuttings were cultured in a growth chamber. Environmental conditions were maintained at 25~ 70% relative humidity, 2000 I~mol.mo1-1 CO2, and 3.5 air exchanges per hour. To provide for air exchange, 0.2 t.tm microfilters were attached to polypropylene film as stoppers. One week after culture, the single-node stems were exposed to one of four light source treatments (blue LED; red LED; mix of half blue and half red LED; or fluorescent lamps) with a 16-h photoperiod and grown under these test conditions for three weeks. PPF was maintained at 100 p.mol'm-2"s -1 by adjusting the distance between the test tubes and the lamps. Environmental conditions inside the chamber were monitored daily with a data logger Model LI-1000 (LI-COR, Lincoln, NE, 247
We investigated the effects of various qualities of light-emitting diode (LED) light sources on the growth and carbohydrate accumulation of grape rootstock 'Teleki 5BB' cultured in vitro. Shoot fresh and dry weights and net photosynthetic rates were increased when plants were exposed to fluorescent lighting (control), red light, or a mixture of blue plus red, but were unaffected by blueonly radiation. Shoot elongation was significantly stimulated by red light whereas the combination of blue and red light was associated with the shortest shoots. However, the number of nodes did not differ among these treatments. Under monochromic blue or red light, sugar content and starch accumulation increased under the mixed-radiation treatment.
We investigated the effect of mixed radiation from light-emitting diodes (LEDs) on the growth and flowering of ageratum, marigold, and salvia bedding plants. Blue, red, and far-red lights were applied under controlled environmental conditions for 28 d. Both the combination of blue-plus-red radiation as well as fluorescent lighting treatment (control) caused increases in dry weights, but shoot lengths were shortest when plants were exposed to blue plus red light compared with either red or blue plus far-red treatments. The number of floral buds as well as the occurrence of flower opening for ageratum and salvia plants was also enhanced under the blue plus red mixture. Likewise, carbohydrate accumulation was stimulated by that combination compared with the other radiation treatments.Keywords: chlorophyll, light-emitting diodes, mixture radiation, morphogenesis, starch Environmental conditions, such as relative humidity, temperature, light intensity, and light quality, commonly influence the growth and development of plants. Among these various factors, light quality affects stem elongation, lateral branching, leaf extension and pigmentation, and photosynthetic activity (Moe and Heins, 1990;Heo et al., 2003;Jayakumar et al., 2004). Desirable morphological characteristics can be obtained when horticultural plants are grown under less light and low temperatures, thereby reducing heat energy costs with only a minimal delay in their blooming (Merritt and Kohl, 1991 ).The objectives of this study were (1) to produce ageratum, marigold, and salvia bedding plants with compact growth, good branching, and a large number of flowers when treated with different mixtures of radiation sources, and (2) to evaluate the starch and sugar contents, as well as the optimum chlorophyll fluorescence, that would cause minimal or no delays in blooming when those plants were grown under various combinations of radiation provided by lightemitting diodes (LEDs). MATERIALS AND METHODS Plant Materials and Growth ConditionsBedding plants of ageratum (Ageratum houstonianum Mill. cv. Blue Field), marigold (Tagetes erecta L. cv. Orange Boy), and salvia (Salvia splendens E Sello ex Ruem & Schult. cv. Red Vista) with two to four true leaves were used for our experimental materials. On Day 14 after sowing, all plants with two true leaves were transplanted to a plug tray (50 x 50 mm) filled with a soil mixture (BM1 ; Berger Horticulture, Canada) of 75 to 85% Canadian sphagnum peat moss, 15 to 20% perlite, and 4 to 10% vermiculite. Two types of liquid fertilizers, 20:10:20 and 14:0:14 (Plant Prod; Plant Products, Canada), were alternately applied at a rate of 100 ppm during the experimental period. We used an LED system (GF-320s; Good Feeling, Korea) comprising LED sticks, a panel, and a main controller to maintain a photosynthetic *Corresponding author; fax +82-43-272-5369 e-mail paekky@chungbuk.ac.kr photon flux (PPF) of 90 _+ 10 ~mol m -2 5 -1 over a 16-h photoperiod, as measured on an empty culture shelf. All plants were reared for 28 d in a growth c...
Abstract. In a plant factory with completely controlled environments, incidence of tipburn in the middle growth stage was observed only in butterhead lettuce at 3012S c e (day/night) when head development was in progress. At 20llS c e in later stage, tipburn was observed 100% in butterhead lettuce and 50% in leaf lettuce. Growth of both lettuces was affected by air temperature, which increased photosynthesis and ion leakage. Highest photosynthesis and growth were observed at 30125°e until the middle stage. In later stage, on the other hand, photosynthesis was the highest at 201l5°e in both lettuces, while growth of leaf lettuce was the fastest at 30125°e, and butterhead lettuce did not show any difference between 30125°e and 201l5°e. Ion leakage in both lettuces was 2.2-2.6 times higher at 30/25°e than that at lOnoe. Butterhead lettuce was mare sensitive to tipburn compared to leaf lettuce. Mass production of quality lettuce in the plant factory can be achieved through optimal temperature management since growth rate is closely related to tipburn incidence. In this experiment, optimum day temperature far butterhead and leaf lettuces was 22 to 26°e in the initial and middle growth stages and 20 to 24°e in the later growth stage. Optimum night temperature was 15 to 20 o e.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.