Kim Hyeon-Hye, Goins Gregory D, Wheeler Raymond M, Sager John C
NASA Biological Sciences Office, Kennedy Space Center, FL 32899, USA.
HortScience. 2004 Dec;39(7):1617-22.
Plants will be an important component of future long-term space missions. Lighting systems for growing plants will need to be lightweight, reliable, and durable, and light-emitting diodes (LEDs) have these characteristics. Previous studies demonstrated that the combination of red and blue light was an effective light source for several crops. Yet the appearance of plants under red and blue lighting is purplish gray making visual assessment of any problems difficult. The addition of green light would make the plant leave appear green and normal similar to a natural setting under white light and may also offer a psychological benefit to the crew. Green supplemental lighting could also offer benefits, since green light can better penetrate the plant canopy and potentially increase plant growth by increasing photosynthesis from the leaves in the lower canopy. In this study, four light sources were tested: 1) red and blue LEDs (RB), 2) red and blue LEDs with green fluorescent lamps (RGB), 3) green fluorescent lamps (GF), and 4) cool-white fluorescent lamps (CWF), that provided 0%, 24%, 86%, and 51% of the total PPF in the green region of the spectrum, respectively. The addition of 24% green light (500 to 600 nm) to red and blue LEDs (RGB treatment) enhanced plant growth. The RGB treatment plants produced more biomass than the plants grown under the cool-white fluorescent lamps (CWF treatment), a commonly tested light source used as a broad-spectrum control.
植物将成为未来长期太空任务的重要组成部分。用于种植植物的照明系统需要具备重量轻、可靠且耐用的特点，而发光二极管（LED）具有这些特性。先前的研究表明，红光和蓝光的组合对几种作物来说是一种有效的光源。然而，在红光和蓝光照明下植物呈现出紫灰色，这使得对任何问题进行视觉评估都很困难。添加绿光会使植物叶子看起来呈绿色且正常，类似于白光下的自然环境，并且可能对宇航员也有心理上的益处。绿色补充照明也可能带来好处，因为绿光能够更好地穿透植物冠层，并有可能通过增加下层冠层叶片的光合作用来促进植物生长。在本研究中，测试了四种光源：1）红光和蓝光LED（RB），2）红光和蓝光LED加绿色荧光灯（RGB），3）绿色荧光灯（GF），以及4）冷白色荧光灯（CWF），它们在光谱的绿色区域分别提供了总光合光子通量（PPF）的0%、24%、86%和51%。在红光和蓝光LED中添加24%的绿光（500至600纳米）（RGB处理）促进了植物生长。RGB处理的植物比在冷白色荧光灯下生长的植物（CWF处理，一种常用作广谱对照的测试光源）产生了更多的生物量。
