Early investigation on cryopreservation of Dendrobium sonia-28 using encapsulation-dehydration with modified Evan blue assay

This study was conducted to determine the potential of cryostoring and regenerating Dendrobium sonia-28 protocorm-like bodies (PLBs) using the encapsulation-dehydration technique. The parameters tested for this study included the PLB size range (1 to 2 and 3 to 4 mm), preculture using six different sucrose concentrations (0.0, 0.2, 0.4, 0.6, 0.8 ahd 1.0 M) and encapsulation using three different sodium alginate concentrations (2.5, 3.0 and 3.5%). Based on initial trials, 1 to 2 mm PLBs that were precultured in 1.0 M sucrose were selected for further studies as they produced the best viability as indicated by the Evans blue (EB) staining method. Subsequently, the PLBs were subjected to a 30 min encapsulation experiment involving the three sodium alginate concentrations. Finally, the chlorophyll content and total soluble protein of cryopreserved, non-cryopreserved and untreated PLBs were determined.