Effect Of R/B Ratio Of Red And Blue LED On Quality Of Sweet Potato In Vitro And Energy-saving

Plant tissue culture is important means for inheritance, breeding, protection of germplasm resources, detoxification and rapid propagation, as a rapid propagation technology getting mass seedling in short time. The traditional artificial light of tissue culture is tubular fluorescent lamps (TFL), which can lead vain growth of tissue culture plantlets and release so much heat that electric energy consumption of air condition is increased.A set of tissue culture light combinded with red LED tube (660nm, 637nm) and blue LED tube (460nm, 450nm) was designed to solve problems of large heat release, low photo active efficiency and short use life of TFL; a tissue culture light system was designed to reduce price of LED light by means of combining the red LED tube with TFL. Influence of the above LED tubes and the combination light on growth of sweet potato plantlets in vitro and cost accounting of LED combination lights were carried on. The main conclusions as follows:1. The physical and optical responses of LED tubes were better than TFL. Range of light intensity of LED tubes was 201.8~246.9μmol·m-2·s-1;range of light quality was 2.2~9.4; uniform of LED tube was 0.94~0.95 and higher 13% than TFL; and light intensity and power of LED tube were linear with duty ratio, so the light intensity could be controlled by change the duty ratio;2. Proper R/B of combination of 660nm red LED tubes and 450nm blue LED tubes was 8, and proper R/B of combination of 637nm red LED tubes and 460nm blue LED tubes was 10. Top-root ratio and root fresh weight were highest and relevance between shoot and root was balanced;3. Combination of 637nm LED tubes and TFL (637F) was the best combination way. The sweet potato plantlets in vitro under 637F were better than there under TFL; significant difference were not showed in height, shoot fresh weight and shoot dry weight compared with sweet potato plantlets in vitro under red and blue LED tubes; significant difference were not showed compared with sweet potato plantlets in vitro under combination of 660nm LED tubes and TFL (660F) expect shoot fresh weight. The 637F could promote both shoot growth and root growth. And proper R/B for 660F and 637F were 10;4. All-in cost each layer of tissue culture light systems were lower than TFL expect the combination of 660nm red LED tubes and 450nm blue LED tubes. The all-in cost of 637F was lower 38.24% than TFL, and price of tissue culture LED light was reduced sharply.