A Successful Surface Sterilization Technique for in vitro Establishment of Dracaena sanderiana Sander ex Mast. Nodal Explants

Abstract

Dracaena sanderiana Sander ex Mast. is the number one cut foliage exported from Sri Lanka and it is also a popular potted plant. In order to promote dracaena cultivation, micropropagation techniques can be employed to produce high quality large number of clones as planting materials. However, severe microbial contaminations in the in vitro establishment stage mitigate the micropropagation application on this species. Therefore, this study was undertaken with the objective of using silver nitrate (AgNO3) to eliminate surface adhered microorganisms to obtain high amount of contamination free cultures at the in vitro establishment stage. Investigations also carried out to explore reusability of AgNO3 after the first wash in surface sterilization. Apical parts of about 8 cm of D. sanderiana cv ‘White’ were used in this study. Silver nitrate solution in 200 mg/L and Clorox™ in 10% concentrations were used for the surface sterilization of the nodal explants. Results revealed that 200 mg/L AgNO3 produced 90% and 10% Clorox produced 20% contamination free cultures after 8 weeks of establishment in vitro. Also, in the experiment of investigation of reusability of AgNO3 it was observed that the second and third washings of AgNO3 produced 80 and 70% non-contaminated cultures, respectively. Results of this study suggest that AgNO3 is a highly effective low-cost non-toxic material which can be used in surface sterilization of D. sanderiana nodal explants. With this promising results it can be suggested that 200 mg/L AgNO3 solution can be considered to replace toxic heavy metals such as mercuric chloride frequently used in Micropropagation.