Fig. 1. Time-course variations in the electron transport rate (ETR), nonphotochemical quenching (NPQ), and Fv/Fm and PSII efficiency (ΦPSII) of Eulophia dentata (A,D,G), Bletilla formosana (B,E,H), and Saccharum spontaneum (C,F,I), respectively. Measurements were made at 25°C under 50, 100, 300, 500, 800, 1,000; 1,500; and 2,000 μmol m–2 s–1 PPFD during the 60 min of light induction. Each point represents the mean of five leaves, and data are means ± standard errors. Different letters indicate significant differences in Tukey's HSD analyses at eight illuminations (P<0.05).
