In Vitro Propagation and Cryopreservation of Banana using Vitrification and Encapsulation Vitrification

Abstract

Micropropagation of banana is limited as explants are difficult to maintain in newlineculture. The present study was conducted to investigate different factors for newlinecryopreservation of banana. This study has two parts. In first part, Invitro propagation of newlinebanana was done to propagate large amount explant for cryopreservation study. Whereas, newlinein second part banana shoot tips were cryopreserved by vitrification and encapsulationvitrification newlinetechnique. During this study, different parameters such as exposure to PVS2 newlineand PVS3 solution, rewarming time, suitable concentration of encapsulation matrix, newlineconcentration of calcium chloride, storage duration and storage temperature were newlineoptimized. newlineFor cryopreservation by vitrification method, shoot tips were precultured on newlinesolidified MS medium supplemented with 0.3 M sucrose for 16 h at 25°C. Then they newlinewere loaded in loading solution containing of 2M glycerol and 0.4 M sucrose for 30 newlineminutes at room temperature. After loading step, shoot tips were dehydrated in plant newlinevitrification solution (PVS2) and (PVS3) with different exposure time (10, 30, 40, 60, 90, newline120 min) respectively. The best result was obtained with shoot tips treated with PVS2 for newline60 min and 120 minutes for PVS3 with survival rate of cryopreserved shoot tips as 85% newlineand 33% respectively. Furthermore, effect of different rewarming times was also newlineinvestigated on shoot tip viability. Among tested different rewarming times (0,2,4 and newline6min), 2 min of rewarming time in PVS2 and 4 min of rewarming time in PVS3 were newlinefound suitable for cryopreservation as they retained survival rate as 97% and 75% newlinerespectively. newlineFurther, suitable concentration of sodium alginate (1%,2%,3% and 4%) and calcium newlinechloride for efficient encapsulation was also determined. By using 3% of sodium alginate newlinewith 100 mM calcium chloride was found best as shoot tips retained high multiplication newlinexiv newlinefrequency of 91.3 percent, when stored 4°C for 15 days. For cryopreservation by newlineencapsulation -vitrification method, shoot tips were precultured on solidified MS me