FIGURE 2.

The effect of light conditions on leaf pigments (A,B,D), soluble sugars (C), photosynthetic indices (E), and growth characteristics (F) of lettuce. Plants grew under constant (con) or parabolic (dyn) blue (B, 452 nm) and/or red (R, 662 nm) LED PPFD at 12, 16, and 20 h photoperiods, but the same DLI; 2.3 and 9.2 mol m^–2 per day for B and R. The data were processed using the XLSTAT software and Tukey’s (HSD) test at confidence level p = 0.05 (biological replicates, n = 5). Neox, neoxanthin; Violax, violaxanthin; Lut + zeax, lutein and zeaxanthin; Carot α + β, α- and β-carotenes; Chl a, Chl b, chlorophylls a and b; Fru, fructose; Glu, glucose; Suc, sucrose; Mal, maltose; CRI, carotenoid/chlorophyll ratio; ARI, anthocyanin amount; Pr, photosynthetic rate; Tr, transpiration rate; C_i/C_a, intercellular to ambient CO₂ concentration.