Figure 2.

Photosynthetic potential, fucoxanthin (Fx), diadinoxanthin and diatoxanthin (Ddx+Dtx) synthesis in Fragilariopsis cylindrus grown under different photoperiods (0 h light:24 h darkness; 6 h L:18 h D; 12 h L:12 h D; 18 h L:6 h D; 24 h L:0 h D) under a ‘white’ spectrum (see Figure S1) with the same photosynthetically usable radiation (PUR) (11.7 µmol photons m⁻² s⁻¹): (a) growth rate (bars), dark-acclimated photochemical efficiency (F_v/F_M, black dots), effective non-photochemical quenching (NPQ_gE, green dots); (b) Fx content (bars), Fx productivity (dots); (c) Ddx+Dtx content (bars), Ddx+Dtx productivity (dots). Data are the mean values n = 3 ± SD. Letters represent clusters of non-significantly different means for the corresponding parameter, with the letter ‘a’ representing the highest mean values and the other letters following in alphabetic order.