采收前不同蓝光补光时段对生菜生长和品质的影响

Effects of Different Pre-Harvest Blue Light Supply Methods on Growth and Quality of Lettuce

摘要: 以“芳妮”生菜为试材，在大棚水培条件下，研究了在生菜采收前48小时不同时段增补蓝光(对照：自然光，T1：连续48 h补光，T2：仅白天12 h补光总计48 h，T3：仅夜间12 h补光总计48 h)对生菜生长、品质、抗氧化性、矿物质元素积累量的影响。结果表明：所有补光处理能提高生菜的生物量。T3处理的效果最为显著。所有补光处理都不同程度的提高了生菜的可溶性糖含量、可溶性蛋白含量、维生素C含量以及生菜的抗氧化性，同时还降低了生菜叶片中的硝酸盐含量。此外，夜间增补蓝光的生菜中钾元素含量较对照显著提高，也高于其他处理，说明夜间补光处理对生菜的生长量的促进影响较之其他两个处理最为显著，但是在提高生菜的品质方面，白天补光的提高效果更为显著，T1处理在生物量与品质提升方面的效果最好，叶片中的钾含量最低。综合生长与品质指标，生菜采收前连续48 h的LED蓝光补光处理可作为为低钾优质生菜生产的参考方案。

Abstract: Using “Fangni” lettuce as material, under the condition of hydroponic cultivation in greenhouse, the effects of adding blue light 48 hours before lettuce harvest (control: Natural Light, T1: Supplement Light 48 hours continuously, T2: supplement light only 12 hours in daytime for 48 hours, T3: supplement light only 12 hours in night for 48 hours) on the growth, quality, antioxidant activity and mineral element accumulation of lettuce were studied. The results showed that all light supply treatments could increase the fresh weight of the above and below ground parts of lettuce, and increase the dry weight of above ground parts. T3 treatment is the best way to promote the growth of lettuce. All light supplement treatments increased the soluble sugar content, soluble protein content, vitamin C content and antioxidant activity of lettuce, and reduced the nitrate content in lettuce leaves. The experiment also found that the potassium content of lettuce treated with blue light at night was significantly higher than that of the control and higher than that of the other two treatments, but in the aspect of improving the quality of lettuce, the effect of supplementing light in the daytime was more significant, and T1 treatment had the best effect in the aspect of biomass and quality. In a word, the aim of the experiment is to improve the quality of lettuce. According to the growth and quality indexes, 48 hours of LED blue light supply before lettuce harvest can be used as a reference for the production of low potassium and high quality lettuce.