Abstract

The aim of this study was to assess the growth response of Sesuvium portulacastrum (L.) (a halophyte) to various NaCl concentrations and hence determine how it is adapted to grow optimally under saline conditions. S. portulacastrum was grown hydroponically in various NaCl concentrations (that is, 0, 100, 200, 400 and 600 mol m^-3 NaCl). It was found to exhibit a growth pattern typical of dicotyledonous halophytes. It attained maximal growth at 200 mol m^-3NaCl concentration in hydroponic cultures. It accumulated large concentrations of Na⁺ and Cl^- with the leaves having the highest ion content. These ions are believed to be sequestered in the vacuole. S. portulacastrum also accumulated proline in high concentrations and this proline appeared to adjust the cytoplasmic ion concentration to balance that of the vacuole.

Key words: Sesuvium portulacastrum, halophyte, proline, salinity.