Abstract:
Salinity is one of the environment factors to limit plant growth development and quantity and quality of plant productivity worldwide. Thailand frequently encounters salinity problems during a summer season. The salinity affects growth and productivity of cut flower that are economically important, especially in Dendrobium. This research was used silicon (Si) compounds to reduce that effects of sodium chloride (NaCl) on in vitro growth of Dendrobium 'Sonia Jo Daeng. This experiment was used calcium silicate (CaSiO3) and silicic acid (H4SiO4) at the concentration of 0, 1.25, 2.5, 5, 7.5 and 10 mM under NaCl at the concentration of 200 and 300 mM at the same time or 7 days prior to transfer Dendrobium to salt stress condition. The result showed that the used of CaSiO3 and H4SiO4 at the concentration of 1.25 mM for 7 days before exposure to NaCl at the concentration of 200 mM promotes the growth and survival rate of Dendrobium when compared to other treatments. In addition, when analyzing some physiological characteristics found that NaCl at the concentration of 200 mM had an effect to increase proline and total soluble sugar accumulation in Dendrobium as well as superoxide dismutase (SOD) and catalase (CAT) activity, moreover, the results showed the excess electrolyte leakage (EL) and malondialdehyde (MDA) content when compared to non-NaCl treatment. However, Si treatments are increased proline and total soluble sugar accumulation including activity of SOD and CAT, but lower EL and MDA content when cultured on salt stress condition. However, Si was inefficient for improving growth of Dendrobium on excess NaCl at the concentration of 300 mM for 10 weeks.