Growth and photosynthetic characteristics of Ceriops roxburghiana under NaCl stress

The plant growth, net photosynthetic rate (P-N), intercellular CO2 concentration (c(i)), and dry matter production of Ceriops roxburghiana Am. were significantly increased with increasing salinity from 0 to 400 mM NaCl. At 600 mM NaCl, shoot and root lengths, and dry mass were significantly depressed with respect to control. Absence of diurnal fluctuation of concentrations of organic acids, and the low activity of phosphoenolpyruvate carboxylase and high activity of ribulose-1,5-bisphosphate carboxylase confirmed the operation of C-3 pathway in Ceriops even at increasing salinity.