| Light spectrum plays an important role in plant development, morphogenesis, metabolism and gene expression. The application of light-emitting diode (LED) in agriculture and bio-industry has been concerned by along with the development of LED technology.The main purpose of nurturing seedling of rice seedling. Seedling of Rice facilities, light quality research to the colored film-based studies have reported less. The objective of this study was to evaluate the effects of different light emitting diode (LED) light sources on the seedlings growth and physiological characteristics of rice cultivars’Wu yu jing’. LED can actualize a lot of functions, such as energy saving, environment protection and efficient space utilization, which can not be achieved by conventional light source.The fluorescent lamp is commonly used light sources in the current organizational culture. Rice tissue culture process is cumbersome, long cycle. LED not only has many advantages, such as small size, long life, low energy consumption, securing wave length and low production of heat, but also can emit the exact spectrum based on the need of plant. LED radiation in various spectral ratio combinations used in the rice tissue culture, in order to find the best light source can be replaced by fluorescent lamp.The results are as follows:1. Light quality had significant effects on the seedling growth of rice cultivars’Wu yu jing’. The growth stage, leaf area, root activity, pigment content, free amino acid content, starch content were greatest in seedlings grown under blue LEDs. Root number, stem length, soluble sugar content, Sucrose content were greatest in seedlings grown under red LEDs. Fresh weight, dry weight, chla/b were greatest in seedlings grown under B:R=1:1 LEDs. Light quality had significant effects on the seedling growth of rice cultivars ’Nipponbare’. Root length, leaf area, chla, chla+b, photosynthetic productions, root activity were greatest in seedlings grown under blue LEDs. The growth stage, fresh weight, dry weight were greatest in seedlings grown under blue plus red LEDs (B:R=1:1). Root number, stem length chlorophyll content were greatest in seedlings grown under red LEDs. The blue LEDs might facilitate the growth of Rice seedlings, and this type of light source may be used as a primary light source for the cultivation of Rice seedlings.2. The effects of the eight light sources on the growth and morphogenesis of Rice were investigated. Light quality had significant effects on the seedling growth. Root number, stem width, dry weight, leaf area were greatest in seedlings grown under B:R=1:1 LEDs. and lowest were greatest in seedlings grown under fluorescent lamps. Root number, fresh weight and dry weight were lowest in seedlings grown under green LEDs. Photosynthetic rate,chlorophyll content and soluble sugar content were greatest in seedlings grown under B:R=1:1 LEDs. The stomatal conductance and ascorbic acid (Vc) content were greatest in seedlings grown under blue LEDs. Light quality had different effects on the contents of phytohormones in seedlings growth. The contents of zeatin riboside (ZR) and abscisic acid (ABA) were greatest in seedlings grown under blue LEDs. The contents of gibberellic acid (GA3) and indole-3-acetic acid (IAA) were greatest in seedlings grown under red LEDs. The content of gibberellic acid (GA3) was lowest in seedlings grown under green LEDs. The content of indole-3-acetic acid (IAA) was lowest in seedlings grown under fluorescent lamps. A mixture of blue and red LEDs in the ratio B:R=1:1 might facilitate the growth of Rice seedlings, and this type of light source may be used as a primary light source for the cultivation of Rice seedlings.3. Results showed that different LED light qualities had different effects on callus proliferation, differentiation, regeneration and the growth of Nipponbare plantlets in vitro. Callus subculture cycle, differentiation and regeneration of matured embryo of rice were lowest under blue LED light. Callus subculture cycle, budding time and seeding time of 16days,17days and 27days, compared to fluorescent lamps were shortened by 4days, 9days and 8days. The frequency of plantlet initiation, differentiation and regenerated plantlet were highest under blue LED light. The results were 86.67%,68.33%,96.67%, respectively. Stem width, dry weight, chlorophyll content, were highest in plantlets cultured under blue LED light. Blue was the most suitable light for the Nipponbare plantlets in vitro, and it may be used as alternative light source for an rice culture system.In summary, the LED light source applications in the Rice Seedling Nursery in B: R=1:1 LEDs than suitable for Wu Yu jing seedlings, blue light is more suitable for the Nipponbare seedlings. Rice tissue culture process in the LED source applications, blue light is more suitable for the Nipponbare tissue culture process. |
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