两种景观灯光源对冬青卫矛生长及光合特性的影响
Effects of Two Landscape Lights on the Growth and Photosynthetic Characteristics of Euonymus japonicas

采用MHL (金属卤化物灯)和LED (发光二极管)模拟景观灯夜间照射4小时，以不照光为空白对照，研究两种景观灯光源对冬青卫矛生长及光合特性的影响。结果表明：MHL为热光源，光谱能量主要集中在绿光和黄光两处，LED为冷光源，光谱能量主要集中在红橙光和蓝光两处。MHL夜间照射能显著提高冬青卫矛的叶面温度2？C (P < 0.05)，LED照射仅高出对照组0.3？C；两种景观灯夜间照射均显著降低了冬青卫矛的株高、叶面积、叶绿素和类胡萝卜素含量以及叶绿素a/b (P < 0.05)，并显著提高了相对电导率和表观量子效率(P < 0.05)，其中MHL照射还会使其叶片形状趋于圆形。除此之外，MHL和LED夜间照射能显著提高可溶性糖含量、比叶重和最大净光合速率(P < 0.05)，其中LED相比MHL效果显著；MHL和LED夜间照射能显著降低光补偿点和光饱和点(P < 0.05)，其中MHL相比LED效果显著。
MHL (metal halide lamp) and LED (light emitting diode) were used to simulate landscape light that illuminated for 4 hours at night. The effects of two landscape lights on the growth and photosynthetic characteristics of Euonymus japonicas were studied with no light as blank control. The results showed that the MHL was heat light source, its spectral energy mainly concentrated in the green and yellow, LED was cold light source, and its spectral energy mainly concentrated in the red, orange and blue. The leaf surface temperature could significantly increase 2？C irradiated by MHL at night, and increase only 0.3？C by LED. Plant height, leaf area, chlorophyll and carotenoid content, chlorophyll a/b were significantly reduced, while relative conductance and apparent quantum efficiency were significantly improved under illumination of two landscape light. The shape of leaves tended to be round in the light of MHL. Irradiation of MHL and LED at night could significantly improve soluble sugar content, lamina mass per unit area, and the maximum net photosynthetic rate, among which LED had significant effect compared with MHL. Irradiation of MHL and LED at night could significantly reduce light compensation point and light saturation point, among which MHL had significant effect compared with LED.