Effects of NaCl Stress on Plant Growth and Antioxidative Defense of Kumquat Seedlings In Vitro

Abstract

Article InfoThis experiment was conducted to determine the effect of salt stress (0, 50, 100, 150 and 200 mM NaCl) on plant growth and antioxidative defense of Kumquat (Fortunella margarita) seedlings in vitro. Stem diameter, leaf number, plant height, root morphology, leaf superoxide dismutase (SOD) and catalase (CAT) activities, and leaf soluble protein content were determined. The Kumquat germination percentage and plant growth significantly reduced with the increasing of NaCl concentrations, and only keeping vitality and no germination in seeds were at 200 mM NaCl concentration. Root biomass and morphological traits (length, projected area, surface area, average diameter, volume, and tips) gradually decreased with the increasing of NaCl concentrations. The leaf soluble protein content and CAT activities of Fortunella margarita significantly decreased with the increasing of NaCl concentrations in vitro, but leaf SOD activities had the highest activity at 50 mM NaCl. It may be suggest that NaCl stress heavily inhibited seed germination at 200 mM level and plant growth and root morphology, and only the kumquat plants possessed an antioxidant enhancement in 50 mM NaCl.