Abstract:

This experiment was conducted to examine the effects of light intensity on growth and physiological characteristics of potted Cyclobalanopsis glauca container seedlings. The results showed that the basal diameter, biomass, quality index of the seedlings varied significantly in different light regime, and these morphological parameters changed from high to low with an increase in light intensity from full sunlight to 5% of sunlight. Chla/ Chlb, Car / Chl, root weight ratio were increased with increasing of light intensity, while the contents of Chla, Chlb and Car, specific leaf area, and leaf weight ratio were decreased. Quantum efficiency of electron transport (Ф_PSII) and photochemical quenching (q_P) in leaves of C. glauca significantly decreased with light intensity, with mean values of Ф_PSII and q_P values changed from 0.701 to 0.131 and from 0.925 to 0.238, respectively. Shading treatment also decreased non-photochemical quenching (NPQ), with the mean values changing from 2.54 to 0.16 with the decrease in light intensity from full sunlight to 5% of sunlight .With an increase in light intensity, malondialdehyde (MDA) content of C. glauca was decreased, but free proline (Pro) content was increased. These results indicated that the C. glauca seedlings would have an excellent shade tolerance, though it is a photophilous tree species.

Key words: Cyclobalanopsis glauca, potted seedlings, light intensities, physiological characteristic