LED光源R／B对叶用莴苣生理性状及品质的影响

研究不同红／蓝（R／B）光强配比对叶用莴苣（LactucasativaL．）生理性状及品质方面的影响，以便为新型人工光源在莴苣生产上的应用提供理论依据。试验利用波长为660nm（±20nm）红光与450nm（±20nm）蓝光发光二极管（LightEmittingDiode，LED）作为人工光源，设置3个R／B试验处理，分别为LED1（R／B=10）、LED2（R／B=8）、LED3（R／B=6），以1个荧光灯处理为对照（CK），选用水耕栽培模式在不同光照环境下培育叶用莴苣30d。结果表明：660nm红光和450nm蓝光组合可以有效提高莴苣的光能利用率，促进光合作用；适宜的红蓝光比例能有效增加植物Vc含量，并降低硝酸盐含量。其中，处理LED2（R／B=8）的叶用莴苣净光合速率及Vc含量明显高于其他试验处理，而硝酸盐含量最低，表现出良好的生理和品质特性，因此，R／B=8相对更适宜叶用莴苣的生长发育。

Influence of R/B Ratio in LED Lighting on Physiology and Quality of Lettuce

The influence of the red-to-blue （R/B） ratio of LED （ Light Emitting Diode） light intensity on the physiology and quality of lettuce （Lactuca sativa L. ） was studied, to provide the scientific foundation for the application of the artificial light source in the lettuce production. The artificial light source was composed by the red light LED whose wavelength was 660nm and the blue light LED whose wavelength was 450nm in this experiment. Three treatments were designed with LED1 （R/B = 10） , LED2 （R/B = 8） and LED3 （R/B = 6） , compared to treatment of fluorescent lamp （CK）. The lettuce was planted by the hydroponic cultivation under different treatments in 30 days. The result showed that the combination of red light and blue light could improve the utilization of light energy and promote photosynthesis. The vitamin C contents would enhance and nitrate contents would reduce effectively though adjusting of R/B ratio. Moreover, in the treatment LED2, the net photosynthetic rate and vitamin C contents were the highest and the nitrate contents were the lowest. The quality and growth of lettuce in the treatment LED2 were better than in other treatments.