Micropropagation in Novel Culture System with Radiation Source Using Superbright Red and Blue Light Emitting Diodes (LEDs)

Abstract

The use of light emitting diodes (LEDs) as a radiation source for plants has attracted considerable interest and attention in recent years because of its vast potential for commercial application. The LEDs have features which are far better than the commonly used radiation sources; fluorescent and incandescent. The most attractive features of LEDs are small mass, volume, solid state construction, and long life. Several plant species have also been reported to grow successfully under LEDs. To date, however, there is no information of superbright red and blue LEDs as a light source for the growth of plantlets cultured in vitro. Therefore, the effects of superbright blue and red LEDs on the growth of Cymbidium plantlets cultured in vitro have been studied. Leaf growth, chlorophyll content and shoot and root weight were affected by different LED irradiations. Red light promoted leaf growth but decreased chlorophyll content. This was reversed by blue light. The growth of Cymbidium plantlets in terms of increase in total shoot and root weight was comparable under red plus blue LEDs and the fluorescent systems. The novel culture vessel, the “UniPACK”, with individual radiation source using superbright blue and red light emitting diodes was also developed by one of the authors (KO). The plantlets cultured in the “UniPACK” were normal and comparable to those cultured under the fluorescent systems. The significance of our findings in relation to the development of a suitable lighting system for plant tissue culture is discussed.