BACKGROUND Red lettuce has been consumed worldwide because it is a great source of natural antioxidants. To design a fertilizer formula to boost its nutritional value, this research simultaneously studied the effects of the significant cationic ions among the macronutrients for plant growth (K, Mg and Ca) and the effects of the electrical conductivity of the nutrient solution on the phenolic compounds production and mass productivity of hydroponically grown red lettuce. RESULTS Red lettuce grown under the control treatment provided the highest mass productivity (under low stress conditions). The highest antioxidant content, measured as mg phenolic compounds per gram dry weight (at a high stress condition) via both Folin-Ciocalteu and HPLC analyses was observed in growth media containing 100 ppm K : 20 ppm Mg : 70 ppm Ca (with EC equal to 1241 μS⋅cm-1 ). It was found that EC within the range of this examination had no significant effect on the mass productivity nor the phenolic compounds productivity. The phenolic compounds productivity, defined as the amount of phenolic compounds produced per unit of planting area per unit of time, was optimized with the optimum formula for maximum phenolic compounds productivity of 90 ppm K : 29 ppm Mg : 77 ppm Ca, or a corresponding EC of 1307 μS⋅cm-1 . CONCLUSION The study demonstrates that health-promoting nutrient production in red lettuce could be stimulated in a practical manner by adjusting the cation concentrations in the fertilizer solution. This article is protected by copyright. All rights reserved.

中文翻译：

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肥料溶液中阳离子对红生菜（Lactuca sativa L.）抗氧化剂含量的综合影响


背景技术红生菜已在全世界范围内被消费，因为它是天然抗氧化剂的重要来源。为了设计肥料配方以提高其营养价值，本研究同时研究了植物生长大量营养素中的重要阳离子离子（钾、镁和钙）以及营养液电导率对酚类化合物的影响水培红生菜的生产和大规模生产力。结果 在对照处理下生长的红生菜提供了最高的批量生产率（在低胁迫条件下）。通过 Folin-Ciocalteu 和 HPLC 分析，在含有 100 ppm K : 20 ppm Mg : 70 ppm Ca（EC 等于至 1241 μS·cm-1 ）。发现本次检查范围内的EC对于量产率和酚类化合物的生产率没有显着影响。酚类化合物生产率定义为每单位种植面积每单位时间产生的酚类化合物量，采用最佳公式进行优化，以获得最大酚类化合物生产率 90 ppm K : 29 ppm Mg : 77 ppm Ca ，或相应的EC 为 1307 μS·cm-1 。结论 该研究表明，通过调整肥料溶液中的阳离子浓度，可以以实际的方式刺激红生菜产生促进健康的养分。本文受版权保护。版权所有。