LED组合光谱对水培生菜矿物质吸收的影响

Effects of LED Spectrum Combinations on the Absorption of Mineral Elements of Hydroponic Lettuce

在植物工厂全密闭环境中水培种植大速生生菜,以光谱比例可调节的LED灯板为植物生长光源,应用电感耦合等离子体原子发射光谱技术(ICP-AES),研究了红蓝LED组合光谱下生菜对K,P,Ca,Mg,Na,Fe,Mn,Zn,Cu,B,Mo等11种营养元素的吸收特性。结果表明:(1)与叶绿素生理吸收波峰(峰值450和660nm)对应的单一或组合光谱均可增强水培生菜根对Na,Fe,Mn,Cu,Mo元素的吸收能力,且单一红光光谱的促进作用最为显著,四种元素含量分别为荧光灯全光谱下的7.8,4.2,5.3,11.0倍;(2)根对K和B元素的吸收量在荧光灯全光谱下达到最大分别为10.309mg·g-1和32.6μg·g-1,而在红、蓝单一或组合光谱下吸收能力降低;(3)单一蓝色光谱下根对Ca和Mg元素的吸收受到抑制,分别比荧光灯对照降低35%,33%;(4)生菜在30%蓝光+70%红光的光谱条件下生物量最高,而在20%蓝光+80%红光条件下对Ca,Mg,Na,Fe,Mn,Zn,B七种元素的累积量达到最大值。试验结果为水培生菜光源光谱选择及营养液配方调节提供了理论依据。

Lettuce （Lactuca sativa） was hydroponically cultured in a completely enclosed plant factory ,in which spectrum pro-portion-adjustable LED panels were used as sole light source for plant grow th .Absorption and content of eleven mineral elements such as K ,P ,Ca ,Mg ,Na ,Fe ,Mn ,Zn ,Cu ,B and Mo in Lactuca sativa under different spectral component conditions were studied by ICP-AES technology .The results showed that ：（1） Single or combined spectrums corresponding to the absorbing peaks of chlorophyll a and b （450 ,660 nm） could enhance the absorbing ability of roots especially for mineral elements Na ,Fe , Mn ,Cu and Mo ,the single red spectrum had the most significant promoting effect under which contents of those four elements were respectively 7.8 ,4.2 ,4.0 and 3.7 times more than that under FL ;（2） Absorption of K and B was the highest under FL which was 10.309 mg · g -1 and 32.6 μg · g-1 while the values decreased significantly under single or combined spectrum of red and blue;（3） Plants grown under single blue spectrum had the lowest absorption of Ca and Mg which respectively decreased by 35% and 33% than FL ;（4） Lettuce grown under the spectrum combination of 30% blue and 70% red had the highest accumula-tions of biomass while those grown under 20% blue and 80% red had the highest accumulations of the following seven elements Ca ,Mg ,Na ,Fe ,Mn ,Zn and B .The results provided theoretical basis for adjusting nutrient solution formula and selecting light spectrum of hydroponic lettuce .