Standardization of vitrification treatments for safe cryoconservation of banana (Musa acuminata Colla) cultivars using differential scanning calorimetry

Cryo-conservation is the most promising approach and reliable method for long term conservation of banana and plantain genetic resources. Prior to the development of a safe cryo-conservation procedure for highly hydrated tissues of any vegetatively propagated crop species such as banana, suitable vitrification treatments involving loading solution in combination with Plant Vitrification Solution 2 (PVS2) solution have to be standardized. In the present study, Differential Scanning Calorimetry (DSC) technique was attempted to identify the best vitrification treatment using shoot apices as storage explants in two banana cultivars namely Grand Naine and Red banana. The results showed that DSC thermogram curves detected the formation of ice nucleation at a temperature of-18.67°C for Grand Naine and-19.16°C for Red banana in the control shoot apices. Among the sixteen vitrification treatment combinations tested, the treatments, LP6, LP7, LP10, LP11, LP14 and LP15 were judged as best treatments for cryo-conservation of both banana cultivars as revealed by the formation of glass transition events in the vitrified shoot apices. This information obtained through DSC experiments would further provide scope for designing safe cryo-conservation system for banana. This is the first report to demonstrate the application of DSC to optimize the vitrification treatments that would be adopted for developing cryo-conservation protocol for Musa germplasm.