Optimization of Explant Surface Sterilization Conditions and Multiple Shoot Induction in Threatened Plant Phanera sirindhorniae

Abstract

Phanera sirindhorniae is a rare species of ornamental and medicinal plants distributed in the upper Northeastern Thailand. It contains many bioactive compounds including tyrosinase inhibitor, which can be used for blocking melanin synthesis of the melasma process. This species has been listed as a threatened species by the Forest Herbarium Department of National Parks, Wildlife and Plant Conservation of Thailand. In vitro propagation techniques for P. sirindhorniae are currently required to help the utilization and conservation of this species. In this study, sterilization steps of the explants were evaluated. The most effective procedure for sterilization with high survival rates is by using the shoot tips treated with 10% NaOCl for 10 min and then 10% NaOCl for 15 min and the nodal explants treated with 10% NaOCl for 10 min and then 5% NaOCl for 15 min. For propagation, shoot multiplication was studied by using shoot tips, nodal explants and cotyledonary nodes incubated on MS media supplemented with BAP at 1, 2, 3 and 4 mg/L for four weeks. The highest shoots were obtained on the MS medium containing 2 mg/L BAP with 4.00, 3.20 and 3.75 shoots per explants from shoot tips, nodal explants and cotyledonary nodes, respectively.