不同频率LED红蓝光交替照射对生菜生长与品质的影响

在全人工光型植物工厂中进行试验,运用供光模式可调的红蓝LED光源,以不同频率的红蓝光交替照射生菜,并以同比例的红蓝光同时照射生菜作为对照组,通过测定生菜生长动态、光合色素、可溶性糖、粗蛋白、维生素C以及硝酸盐含量,研究红蓝光供光模式及交替频率对生菜生长与品质的影响。结果表明:在等能耗基础上,16 h光期里,红蓝光交替1次有利于生菜地上部分生物量、可溶性糖以及粗蛋白的积累;红蓝光交替4次有利于生菜中维生素C的积累以及硝酸盐的代谢;所有处理中,叶绿素及类胡萝卜素含量均以4次和8次红蓝光交替为最大,且二者之间无显著性差异。

Effects of Red and Blue LED Irradiation in Different Alternating Frequencies on Growth and Quality of Lettuce

Lettuce was grown in the fully artificial light plant factory, where adjustable red and blue LED panels were used as the sole light source for lettuce growth. Red and blue light with different alternating frequencies were provided to test plant responses to the alternating red and blue lights. Meanwhile, concurrent red and blue light treatments were set as controls. Results were analyzed in terms of the growth dynamics, and the accumulation of biomass, photosynthesis pigments, soluble sugar, crude protein, vitamin C contents as well as nitrate content in lettuce. The results showed that based on the same energy consumption, alternating red and blue lights with the frequency of one time (R/B1) in a 16h period promoted the accumulation of biomass, soluble sugar and crude protein contents, while alternating red and blue lights with the frequency of four times (R/B4) in a 16h period enhanced the vitamin C content and decreased nitrate content of lettuce. Among all the treatments, the highest chlorophyll and carotenoid contents were both detected under R/B1 or R/B4 treatments, no significant difference existed between the two treatments for the pigment content. Therefore, the focal point was the comparison of red and blue lights provided at the same time and those provided separately with different alternating intervals based on the same daily light integral. The goal was to determine the effects of different radiation modes of red and blue LED lights on the growth and quality of lettuce. The alternating modes would provide methods for deeply studying the relationship of red and blue lights when acting on plants. Meanwhile, the selection of light formula based on the same energy consumption was more acceptable in practical production.