Light emitting diodes (LEDs) now enable precise light quality control. Prior to commercialisation however, the plant response to the resultant light quality regime ought to be addressed. The response was examined here in chrysanthemum by evaluating growth, chlorophyll fluorescence (before and following water deficit), as well as stomatal anatomy (density, size, pore dimensions and aperture heterogeneity) and closing ability. Plants were grown under blue (B), red (R), a mixture of R (70%) and B (RB), or white (W; 41% B, 39% intermediate spectrum, 20% R) light LEDs. Although R light promoted growth, it also caused leaf deformation (epinasty) and disturbed the photosynthetic electron transport system. The largest stomatal size was noted following growth under B light, whereas the smallest under R light. The largest stomatal density was observed under W light. Monochromatic R light stimulated both the rate and the degree of stomatal closure in response to desiccation compared with the other light regimes. We conclude that stomatal size is mainly controlled by the B spectrum, whereas a broader spectral range is important for determining stomatal density. Monochromatic R light enhanced stomatal ability to regulate water loss upon desiccation.

现在，发光二极管（LED）可以实现精确的光质量控制。然而，在商业化之前，应该解决工厂对最终光质状况的反应。通过评估生长，叶绿素荧光（缺水前后）以及气孔解剖结构（密度，大小，孔尺寸和孔径异质性）和闭合能力，在菊花中检查了响应。使植物在蓝色（B），红色（R），R（70％）和B（RB）的混合物或白色（W； 41％B，39％中间光谱，20％R）发光LED下生长。尽管R光促进了生长，但它也引起了叶片变形（易弯曲）并扰乱了光合电子传输系统。在B光下生长后发现最大的气孔大小，而在R光下最小。在W光下观察到最大的气孔密度。与其他光方案相比，单色R光刺激了干燥引起的气孔关闭速率和程度。我们得出的结论是，气孔大小主要受B光谱控制，而更宽的光谱范围对于确定气孔密度很重要。单色R光增强了气孔调节干燥时失水的能力。