LED绿光补光模式对生菜生长及品质的影响

【目的】探究不同光照强度以及补光模式的绿光对植物工厂中水培生菜生长及营养品质的影响,为绿光的供光策略提供参考。【方法】以8:00—20:00照射的强度为160μmol·m~(-2)·s~(-1)的LED白光(W)为基础光,在保证生菜正常生长的前提下,补充3种不同强度(30、60、90μmol·m~(-2)·s~(-1))的绿光(G),并通过调节绿光的供光时间点使之与基础白光形成重叠(O)和不重叠(N)两种供光模式,分别为W、WG30O、WG60O、WG90O、WG30N、WG90。N共6个处理,各处理间绿光补光时长均为6 h。【结果】除处理WG90N外,其他补充绿光的处理较对照W均显著提高了生菜地上部鲜重,且30μmol·m~(-2)·s~(-1)的低强度绿光更有利于生菜的生长及生物量积累;补充绿光的处理均不同程度的提高了生菜可溶性糖、粗蛋白以及Vc含量,同时降低了硝酸盐含量,其中,生菜可溶性糖、粗蛋白以及Vc含量随着绿光补光强度的升高而增加;绿光在作用于生菜生物量积累过程中依赖于背景白光,而在作用于可溶性糖积累和Vc合成过程中与背景白光的关系不显著。【结论】绿光对生菜的作用效果与绿光补光强度及其相对于基础光的供光模式有关,且对于不同的目的指标,绿光补光效果有所差异,在实际生产中可根据生产目的建立不同的绿光补光策略。

Effects of Green LED Light on the Growth and Quality of Lettuce

【Objective】 To explore the better mode of green LED light supply in plant factories, the effects of different modes of green light on the growth and nutrient quality of lettuce were analyzed.【Method】Lettuce was grown in the fully artificial light plant factory, where adjustable white and green LED panels were used as the sole light source for lettuce growth. White light (W) provided at 8:00-20:00 (160 μmol·m^-2·s^-1) was regarded as the basal light for normal growth of lettuce, and green light (G) at different intensity (30, 60, and 90 μmol·m^-2·s^-1) was supplied as the supplemental light. Meanwhile, overlapping mode (O) and non-overlapping mode (N) of the basal white light and the green light were set by regulating the green light time. Treatments were recorded as W, WG₃₀O, WG₆₀O, WG₉₀O, WG₃₀N and WG₉₀N, and the green light period for all treatments was 6 h. 【Result】 All treatments were observed to enhance the shoot fresh weight of lettuce compared with the control except treatment of WG₉₀N, 30 μmol·m^-2·s^-1 low intensity of supplemental light was more beneficial for the growth and biomass accumulation of lettuce. Supplemental green light promoted the accumulation of soluble sugar, crude protein and vitamin C at different levels, and decreased the nitrate content at the same time. Among which, the soluble sugar, crude protein and Vc contents increased with the increase of green light intensity. Green light depended on the exist of basal white light on the biomass accumulation of lettuce, but the green light didn’t show the dependent on the basal white light on the process of the soluble sugar and vitamin C. 【Conclusion】 The effects of green light supply are relevant to the light intensity as well as the supply modes. Green lighting strategy can be established and adjusted according to the production purpose in the actual production.