Cope Kevin R, Snowden M Chase, Bugbee Bruce
Crop Physiology Laboratory, Department of Plants Soils and Climate, Utah State University, Logan, Utah.
Photochem Photobiol. 2014 May-Jun;90(3):574-84. doi: 10.1111/php.12233. Epub 2014 Jan 18.
Photosynthesis (Pn) and photomorphogenesis (Pm) are affected by light quality, light intensity and photoperiod. Although blue light (BL) is necessary for normal development, it is less efficient in driving Pn than other wavelengths of photosynthetically active radiation. The effects of BL on Pm are highly species dependent. Here we report the interacting effects of BL and photosynthetic photon flux (PPF) on growth and development of lettuce, radish and pepper. We used light-emitting diode (LED) arrays to provide BL fractions from 11% to 28% under broad-spectrum white LEDs, and from 0.3% to 92% under monochromatic LEDs. All treatments were replicated three times at each of two PPFs (200 and 500 μmol m(-2) s(-1)). Other than light quality, environmental conditions were uniformly maintained across chambers. Regardless of PPF, BL was necessary to prevent shade-avoidance responses in radish and lettuce. For lettuce and radish, increasing BL reduced stem length, and for both species, there were significant interactions of BL with PPF for leaf expansion. Increasing BL reduced petiole length in radish and flower number in pepper. BL minimally affected pepper growth and other developmental parameters. Pepper seedlings were more photobiologically sensitive than older plants. Surprisingly, there were few interactions between monochromatic and broad-spectrum light sources.
光合作用（Pn）和光形态建成（Pm）受光质、光强和光周期的影响。虽然蓝光（BL）对正常发育是必需的，但在驱动光合作用方面，它比光合有效辐射的其他波长效率更低。蓝光对光形态建成的影响高度依赖于物种。在此，我们报告了蓝光和光合光子通量（PPF）对生菜、萝卜和辣椒生长发育的相互作用效应。我们使用发光二极管（LED）阵列在广谱白色LED下提供11%至28%的蓝光比例，在单色LED下提供0.3%至92%的蓝光比例。所有处理在两个光合光子通量（200和500 μmol m(-2) s(-1)）下各重复三次。除光质外，各试验箱内的环境条件保持一致。无论光合光子通量如何，蓝光对于防止萝卜和生菜的避荫反应都是必需的。对于生菜和萝卜，增加蓝光会缩短茎长，并且对于这两个物种，蓝光与光合光子通量在叶片扩展方面存在显著的相互作用。增加蓝光会缩短萝卜的叶柄长度并减少辣椒的花数。蓝光对辣椒生长和其他发育参数的影响最小。辣椒幼苗比成年植株对光生物学更敏感。令人惊讶的是，单色光源和广谱光源之间几乎没有相互作用。
