Light environment is one of the important physical environment factors indispensable for plant growth and development. Controlling plant morphogenesis through light quality regulation is an important technology in the field of protected cultivation. As the fourth generation of new lighting source, LED has many characteristics different from other electric light sources (Table 1), which makes it the first choice for energy-saving and environmental protection light sources. LED used in plant culture also shows the following characteristics: rich wavelength types, just in line with the spectral range of plant photosynthesis and photomorphogenesis; The spectral width is narrow at half width, and pure monochromatic light and composite spectrum can be obtained by combining as needed. Light with a specific wavelength can irradiate crops uniformly and intensively; It can not only regulate the flowering and fruiting of crops, but also control the plant height and nutritional components. The system generates less heat and occupies less space, and can be used in multi-layer breeding stereo combination system to realize low heat load and miniaturization of production space. In addition, its strong durability also reduces operating costs. Because of these remarkable characteristics, LED is very suitable for plant cultivation in controlled facilities, such as plant tissue culture, facility gardening and factory seedling raising, aerospace ecological life support system and so on.
LED is attracting the world's attention with its inherent superiority. Especially in the context of increasing global energy shortage concerns, LED light source has the characteristics of high luminous efficiency, long service life, safety, reliability, environmental protection and energy saving, which makes the prospect of LED in the lighting market attract worldwide attention.