Salt Tolerance Assessment with NaCl of Stauntonia hexaphylla (Thunb.) Decene. and Raphiolepis indica var. umbellata (Thunb.) Ohashi

Abstract

Stauntonia hexaphylla and Raphiolepis indica, cold-tolerant broadleaved evergreens ranging through the southern region of South Korea, were assessed on salt tolerance with NaCl treatment using visual damage, chlorophyll florescence image, and malondialdehyde (MDA) analysis. As NaCl concentrations increased, the soil pH decreased and EC increased, and the soil of S. hexaphylla was affected more strongly by the treatment than that of R. indica. In visual damage, S. hexaphylla withered above 200 mM NaCl at 20 days after the treatment. All individuals of R. indica survived during the experiment though the leaves of R. indica showed visual damages up to 400 mM NaCl. The color changes in chlorophyll fluorescence showed a strong correlation with the degree of visual damage. As NaCl increased, the red color of the leaves of S. hexaphylla was distinctly changed to blue and chlorophyll fluorescence decreased starting from the margin to the middle of a leaf. R. indica showed subtle color changes and remained in red color during the experiment. At five days after the NaCl treatment, the MDA of S. hexaphylla was above 4.56 nmol.g(-1) when plants showed the highest visual damage and EC, The MDA of R. indica in all treatments showed below 1.5 nmol.g(-1) except 400 mM NaCl treatment during the experiment.