In Vitro Salt Tolerance of Plantlets in Dendrobium Sonia ‘Earsakul’

Abstract

Dendrobium is an important ornamental plant in Thailand. The main cultivation areas are in Samut Sakhon and Nakhon Pathom provinces that encountered with salinity water problems during the dry season. This study aims to find out the appropriate NaCl concentration for salt tolerance selection of Dendrobium Sonia 'Earsakul' plantlet which is able to develop into a complete plant by using tissue cultured techniques. The plantlets that cultured under 50 mM NaCl added on modified Vacin and Went (VW) solid medium were subcultured to modified VW solid medium supplemented with 0, 50, 75 and 100 mM NaCl and without NaCl (control; NS) for 4 months. The completely randomized design with 5 treatments was applied. The results exhibited that high vegetative growth and highest root growth were found in 0 mM NaCl following by the control (NS) and 50 mM NaCl. Furthermore, the increase in NaCl concentrations resulted in depletion of chlorophyll a, b, total chlorophyll and carotenoid contents, but proline accumulation and electrolyte leakage in leaf were increased with NaCl higher than 50 mM. These results indicated that the damage in plant cells occurred under excess NaCl. In conclusion, Dendrobium Sonia 'Earsakul' was able to culture on modified VW solid medium supplemented with 50 mM NaCl that approached to produce the salt tolerance plantlet of Dendrobium Sonia 'Earsakul' in vitro culture.