红蓝复合光谱对两个生态型羊草光合生理特性的影响

采用LED红蓝光源激发产生不同比例、不同强度红蓝复合光，对实验控制培养的两个生态型羊草光合生理特性进行研究。两个生态型羊草在红蓝复合光低于50 μmol·m-2·s-1时光合作用不能进行，红蓝复合光强高于50 μmol·m-2·s-1后，光合速率、气孔限制值和蒸腾速率不断上升，但灰绿型羊草在红蓝复合光达到1 150 μmol·m-2·s-1、黄绿型羊草在红蓝复合光达到907 μmol·m-2·s-1后，光合速率不再增加，出现光饱和现象，同时气孔限制值增加以减少水分过多的消耗，蒸腾速率下降。植物在各个生理指标之间进行权衡，保证在生理损伤最小的情况下获得最大生产能力。在高光条件时，蓝光对光合的作用已逐渐消弱，红光对光合生理的作用逐步增强。在同样的红蓝复合光源照射条件下，灰绿型羊草在保持较低的气孔限制和较高水平水分消耗时，依旧能有较高的光合速率，表明灰绿型羊草光合生产能力和生理的适应性强于黄绿型羊草。对两个生态型羊草光合生理特性产生影响的主要因素就是红蓝复合模拟光谱。

Effect of Red and Blue Spectrum on Photosynthesis Physiological Characteristics of Two Ecotypes of Leymus Chinensis

Photosynthesis physiological characteristics of two ecotypes of Leymus chinensis were studied under different red and blue light excitation by LED red and blue lamp-house. Photosynthesis did not carry on under red and blue light of 50 micromol x m(-2) x s(-1). When red and blue light intensity was increased, photosynthesis rate, stoma limit value and transpiration rate of the two ecotypes of Leymus chinensis were all increased. But photosynthesis rate stopped increasing under red and blue light of 1 150 micromol x m(-2) x s(-1) for grey-green ecotype Leymus chinensis and of 907 micromol x m(-2) x s(-1) for yellow-green ecotype Leymus chinensis, which is known as light saturation. And the effect of blue light on photosynthesis became weaker than red light under higher light intensity. Increasing light intensity can promote plant photosynthesis rate in the range of low light intensity. But when light intensity reaches light saturation, photosynthesis rate does not increases but decreases. Because though light quantum numbers is increasing, the numbers of coloring mater does not change and is saturated. On the other hand, when the light intensity is of light saturation, the stoma limit value was increased and the transpiration rate was decreased in order to reduce water waste. When light intensity reaches the value that plant can bear, the plant will automatically close stoma in order to decrease transpiration and to save water. Plant balances every physiological index and makes sure that physiology damage is the least and production is the greatest. Although grey-green ecotype Leymus chinensis has lower stoma limit and higher water waste, it also has higher photosynthesis rate than yellow-green ecotype Leymus chinensis. And the photosynthesis capability and physiology adaptation of grey-green ecotype Leymus chinensis is greater than that of yellow-green ecotype Leymus chinensis.