Sweet basil (Ocimum basilicum L.), one of the most widely consumed herbs globally, is used in raw or processed food, and for aromatic essential oils. We investigated the effects of photosynthetic photon flux density (PPFD; 150, 225, and 300 μmol·m⁻²·s⁻¹, herein, referred to as P150, P225, and P300) and red to blue light ratios (R/B ratio) (R:B = 1:4, 1:1, and 4:1, herein, referred to as R/B 0.25, 1.0, and 4.0) with a 16 h light period on the leaf shape and concentrations of functional and aromatic compounds in basil. Total leaf dry weight and leaf mass per area increased with increasing PPFD and R/B ratio. Total leaf area tended to increase with increasing R/B ratio at the same PPFD. Although the highest growth was noted when R/B was 4.0 at P300, the leaves showed ruggedness and curling. β-Carotene concentration based on the leaf dry weight and leaf area at the fourth node increased with decreasing R/B ratio, regardless of PPFD. Concentrations of aromatic compounds (eugenol and linalool) based on dry weight were significantly higher at P150 than at other PPFDs and in treatments with greater amounts of red light. These results suggest that basil growth, appearance, and functional and aromatic compound concentrations can be adjusted as needed by manipulating the PPFD and R/B ratio, although R/B 4.0 at P300 caused malformed leaves.

甜罗勒 ( Ocimum basilicum L.) 是全球消费最广泛的草药之一，用于生食或加工食品以及芳香精油。我们研究了光合光子通量密度 (PPFD; 150、225 和 300 μmol·m ^-2 ·s ^-1，本文中称为 P150、P225 和 P300）和红蓝光比（R/B 比）（R:B = 1:4、1:1 和 4:1，本文中称为 R/ B 0.25、1.0 和 4.0) 与 16 小时光照周期对罗勒中的叶形和功能性和芳香族化合物的浓度的影响。总叶片干重和单位面积叶片质量随着 PPFD 和 R/B 比的增加而增加。在相同的 PPFD 下，总叶面积倾向于随着 R/B 比的增加而增加。尽管在 P300 下 R/B 为 4.0 时观察到最高的生长，但叶子表现出粗糙和卷曲。与 PPFD 无关，基于叶干重和第四节叶面积的 β-胡萝卜素浓度随着 R/B 比的降低而增加。基于干重的芳香族化合物（丁子香酚和芳樟醇）的浓度在 P150 处显着高于其他 PPFD 和具有更多红光的处理。这些结果表明，罗勒的生长、外观以及功能性和芳香族化合物的浓度可以根据需要通过操纵 PPFD 和 R/B 比率进行调整，尽管 P300 下的 R/B 4.0 会导致叶片畸形。