LED光谱对模拟空间培养箱中植物生长发育的影响

通过研究在空间植物培养箱中利用LED作为光源对植物生长发育的作用, 并以荧光灯作为对照, 评估LED光源在空间植物培养中的优缺点, 可为中国即将在空间实验室天宫二 号和空间站中开展的高等植物生长实验提供参考. 利用不同比例的红光与白光LED组合光源, 研究光谱组成(红蓝光比例)、光照强度、光周期和气体流通等条件对于模拟空间 植物培养箱中拟南芥和水稻生长发育的影响. 结果表明, 与荧光灯相比, 红蓝光比例高的LED会导致拟南芥提早开花和水稻叶片的早衰. 红蓝光峰值比在3.9左右时, 拟南芥 和水稻生长最为有利; 红蓝光峰值比超过16则明显抑制拟南芥和水稻的生长, 导致叶片早衰. 另外, 在密闭培养箱中, 光强小于150μmol·m^-2·s^-1时, 增加光照强度可以部分抵消气体流通不足导致拟南芥植物生长的抑制, 而光照强度大 于150μmol·m^-2·s^-1时, 光强越大拟南芥的生长发育受到抑制越严重. 水稻对密闭培养环境中高光强的耐受性明显好于拟南芥. 因此, 在设计空间植物培养箱的LED光照系统时, 红蓝光的比例选择是关键, 此外还需综合考虑空间微重力条件下气体对流变化影响植物对光的反应.

Effect of LED on Plant Growth and Development in Space Culture Chamber Simulator

The goal of this study is to analyze the influence of LED light on the growth and development of plant in the plant culture chamber simulator for space experiment. The daylight fluorescence lamp was used as control to investigate the advantages and disadvantages of using LED in the plant cultivation, to provide reference data for the experiments of plant culture on board Chinese space lab TG-2 or space station in the near future. This paper focused on the influence of different LED conditions, e.g. spectra component, light intensity, light period and air exchange, on the growth of Arabidopsis thaliana and rice at different developmental stages. The results indicated that higher ratio of red to blue light could induce early flowering and early senescence in Arabidopsis and rice, respectively. The optimum ratio of red to blue light for the growth of Arabidopsis and rice is around 3.9. When the ratio is higher than 16, the growth of both Arabidopsis and rice was suppressed and leaf senescence was induced. In closed container, increased light intensity up to 150μmol·m-2·s-1 could partially release Arabidopsis growth inhibition caused by limited air exchange. When light intensity is higher than 150μmol·m-2·s-1, the growth and development of Arabidopsis were severely inhibited. For rice, the tolerance to high light was higher than Arabidopsis under limited air exchange conditions. Thus, the red to blue ligh ratios, light intensity and limited air exchange in microgravity environment should be considered when LED is used as light source in space plant culture chamber.