Photoperiodic light quality affects flowering of long day plants, by influencing the phytochrome photoequilibria (PPE) at plant level, however the most effective light spectrum to promote flowering is still unknown for most the flower crops. We evaluated the influence of light spectrum of three light sources, with different induced PPE, on photosynthesis, metabolic profiling and plant growth and flowering in two hybrids of Ranunculus asiaticus L., MBO and MDR. Three photoperiodic treatments were compared to natural day length (NL): white fluorescent light (FL, PPE 0.84), LEDs Red:Far Red light at 3:1 ratio (R:FR 3:1, PPE, 0.84), and LEDs Red:Far Red light at 1:3 ratio (R:FR 1:3, PPE 0.63). Under natural light, net photosynthesis was higher in MDR than in MBO, while photochemistry was similar in the hybrids. Compared to NL, photoperiodic treatments did not affect net photosynthesis, while they promoted the quantum yield of PSII and reduced the non-photochemical quenching. Under NL, plant growth was greater in MBO, while flowering started earlier in MDR and flowers characteristics were similar in the hybrids. Despite the greater sensitivity of MDR plants in terms of metabolism, photoperiodic lighting improved plant growth and reduced the flowering time only in MBO, with a stronger effect under R:FR 3:1 light. MDR plants were characterized by higher soluble sugars, polyphenols, photosynthetic pigments and proteins, while MBO plants by higher starch and amino acid content. The morphological effects of photoperiodic light quality and the hybrid-specific response should be taken into account to optimize lighting protocols in commercial farms. This article is protected by copyright. All rights reserved.

中文翻译：

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光周期光照光质对毛茛光合作用、开花和代谢谱的影响。

光周期光质量通过影响植物水平的光敏色素光平衡（PPE）来影响长日照植物的开花，但是对于大多数花卉作物来说，促进开花的最有效光谱仍然未知。我们评估了具有不同诱导 PPE 的三种光源的光谱对毛茛、MBO 和 MDR 的两个杂种的光合作用、代谢谱和植物生长和开花的影响。将三种光周期处理与自然日长 (NL) 进行比较：白色荧光灯 (FL, PPE 0.84)、LED 红光：远红光 3:1 比率 (R:FR 3:1, PPE, 0.84) 和 LED 红光：远红光比例为 1:3（R:FR 1:3，PPE 0.63）。在自然光下，MDR 的净光合作用高于 MBO，而杂种中的光化学相似。与NL相比，光周期处理不影响净光合作用，但它们促进了 PSII 的量子产率并减少了非光化学猝灭。在 NL 下，MBO 中的植物生长更大，而 MDR 中开花开始得更早，并且杂种中的花朵特征相似。尽管 MDR 植物在代谢方面具有更高的敏感性，但光周期照明仅在 MBO 中改善了植物生长并减少了开花时间，在 R:FR 3:1 光下效果更强。MDR 植物的特点是可溶性糖、多酚、光合色素和蛋白质含量较高，而 MBO 植物的特点是淀粉和氨基酸含量较高。应考虑光周期光质量和杂交特异性响应的形态效应，以优化商业农场的照明协议。本文受版权保护。版权所有。