Biochemical and Physiological Characteristics of Photosynthesis in Plants of Two Calathea Species.

Plants of the genus possess many leaf colors, and they are economically important because they are widely used as ornamentals for interior landscaping. Physiological performances and photosynthetic capacities of and were investigated. The photosynthetic efficiencies of and were significantly increased when the photosynthetic photon flux density (PPFD) increased from 0 to 600 μmol photons·m·s and became saturated with a further increase in the PPFD. The two species had lower values of both the light saturation point and maximal photosynthetic rate, which indicated that they are shade plants. No significant differences in predawn Fv/Fm values (close to 0.8) were observed between dark-green (DG) and light-green (LG) leaf sectors in all tested leaves. However, the effective quantum yield of photosystem II largely decreased as the PPFD increased. An increase in the apparent photosynthetic electron transport rate was observed in both species to a maximum at 600 μmol·m·s PPFD, following by a decrease to 1500 μmol·m·s PPFD. Compared to LG leaf extracts, DG leaf extracts contained higher levels of chlorophyll (Chl) , Chl , Chls + , carotenoids (Cars), anthocyanins (Ants), flavonoids (Flas), and polyphenols (PPs) in all plants, except for the Ant, Fla and PP contents of plants. also contained significantly higher levels of total protein than did . The adjusted normalized difference vegetation index (NDVI), photochemical reflectance index (PRI), red-green, and flavonol index (FlavI) were significantly correlated to leaf Chls + , Cars, Ants, and Flas in , respectively, and can be used as indicators to characterize the physiology of these plants.