Influence of paclobutrazol on growth of Dendrobium ‘Sonia Jo Daeng’ under salt stress condition in tissue culture

Abstract

Contaminated soil water in irrigation systems is one of the important problems for orchids growing in Sampran district, Nakhon Pathom province as well as Krathum Baen district, Samut Sakhon province, Thailand. Salinity reduces plant growth and productivity, therefore, this study aimed to analyze the effect of salinity and paclobutrazol (PBZ) on in vitro growth of Dendrobium ‘Sonia Jo Daeng’. The first experiment involved evaluating the effect of salinity on Dendrobium growth in plant tissue culture condition. The results showed that high salt concentration reduced the survival rate of Dendrobium plantlets and the percentage of mortality. The median lethal concentration (LC50) of NaCl was 193.3 mM. A higher percentage of survival rates at the PBZ concentration of 0.5 mg/L. Additional experiments from PBZ, supplemented with VW at 0.5 mg/L, have demonstrated a 100% survival of new shoots. This is probably due to the negative effect of PBZ on salt stress in Dendrobium ‘Sonia Jo Daeng’ and promoted the percentage of survival rate in tissue culture.