Effects of light-emitting diodes on tissue culture plantlets and seedlings of rice(Oryza sativa L.)

Light-emitting diodes(LEDs) are a new light source with low energy consumption and high photoelectric conversion efficiency, and they can satisfy the energy-saving needs of plant culture systems. However, the effects of LED light sources on rice tissue culture and rice seedling cultivation are poorly understood. This study aimed to evaluate the effects of LEDs on the growth of tissue culture plantlets and seedlings of the rice(Oryza sativa L.) cultivar Nipponbare. The best light source for rice tissue culture was different from that for rice seedling cultivation. Blue(B) LED light was the most appropriate light for rice tissue culture. Under a B LED light, the time required for callus proliferation, differentiation and regeneration was the shortest, and the frequency of plantlet initiation, differentiation and regeneration was the highest. A blue:red(B:R)=1:1 LED light facilitated the growth of rice seedlings and produced the highest chlorophyll and carotenoid contents and photosynthetic rates in the rice seedlings. Abundant photosynthetic products were more effectively generated in the rice seedlings under the B:R=1:1 LED and R LED lights than under the B LED light. B LED light is the most appropriate light for rice tissue culture plantlets and can be used as an alternative light source for rice tissue culture, and B:R=1:1 LED light facilitated the cultivation of robust rice seedlings and can be used as the primary light source for rice factory seedling cultivation.