关键词: 叶用莴苣, 光合特性, 发光二极管, LED, 波峰, R/B

Abstract: To research the energy-saving and high-efficiency lighting parameters suitable for lettuce growth，LEDA and LEDB lighting were used. LEDA lighting was composed of red with peak at 660 nm（R）and blue with peak at 450 nm（B），LEDB lighting was composed of red with peak at 630 nm（R）and blue with peak at 460 nm（B）. Treatments with R/B ratio of 6，8，10 were performed with LEDA and 　　 LEDB respectively. Results showed that photosynthetic rate of lettuce was significantly higher under LED lighting than under fluorescent lamp. There were no significant differences in photosynthetic rate，transpiration rate，stomatal conductance，intercellular CO2 concentration，vitamin C，total sugar and nitrate content of lettuce between LEDA and LEDB. All those indices showed the same change trend with R/B，and they were the best at the R/B ratio of 8（LEDA2，LEDB2）. Compared with fluorescent treatment，photosynthetic rate and vitamin C content increased 38% and 8.3% respectively，while nitrate content decreased 9.2% in LEDA2 treatment，and photosynthetic rate increased 48% and nitrate content decreased 6.5% in LEDB2 treatment. The content of chlorophyll a，b and（a + b）were significant higher under LEDA lighting than under LEDB lighting，and were the highest under LEDA3 and LEDB2 treatments，respectively. In addition，results of power consumption of lighting device showed，compared with LEDA lighting and fluorescent，the power consumption per plant of LEDB lighting decreased 53.3% and 27.2%，respectively. Thus，LED lighting composed of red with peak at 630 nm and blue with peak at 460 nm，while R/B = 8，not only could improve photosynthesis rate and quality，but also is more energy-saving than other treatments. The aim of efficient and energy-saving was achieved from above three aspects.

Key words: lettuce, photosynthetic characteristics, light emitting diode, LED, peak wavelength, R/B