Light-Emitting Diodes (LEDs): An Artificial Lighting Source for Biological Studies

In Vitro Organogenesis of Protea cynaroides L. Shoot-Buds Cultured Under Red and Blue Light-Emitting Diodes

“…Similar findings were also reported in Gerbera jamesonii where an almost identical number of leaves was found in plantlets cultured under red LEDs and blue LEDs (Wang et al (2011). However, according to Nhut & Nam (2010), red LEDs promote leaf growth, but the amount of chlorophyll decreases, thereby reducing the quality of the leaves. This statement is supported by results of a study by Chang et al (2003) where the chlorophyll content of calla lily leaves were found to be significantly higher when grown under blue lights compared to those cultured under red lights.…”

The Effects of Various LED Light Wavelengths to the Physiological and Morphological Parameters of Stevia (<i>Stevia rebaudiana</i>) Bertoni

“…Furthermore, because the plants grown under red LED had less chlorophyll and photosynthesis ratio, yellowing was observed in their leaves. Nevertheless, according to some reports, a normal plant growth can be observed even just under red light without blue light depending on plant type (Nhut and Nam, 2010). As for our study, very low chlorophyll amount was determined in intense red light application and the negative "a" value representing the chlorophyll quantity in leaf and green color of leaf was obtained in same application.…”

“…red, 650-700 nm) incite the elongation of plants (Çağlayan and Ertekin, 2011). Red light is effective on stem elongation of plant, leaf growth and chlorophyll synthesis (Tripathy and Brown, 1995) but it can cause to decrease in chlorophyll content of leaf (Nhut and Nam, 2010). When the plants that include extremely high chlorophyll are compared, the plants that include less chlorophyll use chlorophyll more efficiently (Saebo et al, 1995).…”

Effects of Light Quality on Vegetative Growth and Flower Initiation in Phalaenopsis

“…This assumption was based on the fact that the total chlorophyll contents also higher in those seedlings compared to those seedlings grown under red LEDs or control condition ( Figure 3 and Figure 4) It was suggested that blue light controls stomatal conductance rather than red light, and that red LEDs may cause lower photosynthesis through lower stomatal condustance. In addition, the narrow peak emission of red LEDs also leads to an imbalance of photons available to both (n=5) photosystem I and II, thus altering the ratio of cycle to whole chain reaction transport, and causing a reduction in net photosynthesis (Nhut and Nguyen, 2010). However, in Paphiopedilum, red light given together with blue light enhanced stomatal opening (Talbott et al, 2002), whereas Jao and Fang (2003) found that for Phalaenopsis plantlets in vitro grown under red-blue LEDs only show a slight increase in leaf length compared to those plants grown under TFLs.…”

“…There are several advantages in using LED lamps, such as lower energy consumption, longer lifetime, improve robustness, smaller size, faster switching, and greater durability (http://www.en.wikipedia.org.wiki/LED_ lamp). The effects of LED lamps have been evaluated on several plant species, however, the responses are species dependent (Nhut and Nguyen, 2010). In Phalaenopsis, it was found that total leaf area were increased under LED compared to those under TFLs (Jao and Fang, 2003;Hsu and Chen, 2010) Flowering is critical for growth and reproduction in plants and is controlled by both environmental and endogenous conditions.…”