SUCCESSFUL PRESERVATION OF BANANA EMBRYOGENIC CALLUS BY MINIMAL GROWTH AND CRYOPRESERVATION TECHNIQUE

Abstract

This paper reports successful preservation methods by minimal growth and cryopreservation of banana embryogenic callus. The minimal growth and cryopreservation techniques can be applied for medium-term and long-term preservation. The embryogenic callus of banana cv Dwarf Parfitt was used as the plant material. Different kind of medium formulations, temperature, gelling agents, and ABA concentrations were tested in minimal growth study. The type of explants, dehydration periods, and preculture media were tested in cryopreservation study. The result showed that the use of WIC medium was better than BM2G for maintaining embryogenic callus. The application of 0.005 mg L-1 ABA combined with reduced temperature (150C) could preserve the cultures longer than 4 months with high survival rate (95%), high recovery rate (90%), and high number of recovered embryos indicating high embryogenic potential. For cryopreservation study, the best dehydration period was 20 minutes. The combined treatments of 150 g/l sucrose and 2 M glycerol at preculture step was the most suitable treatment for successful cryopreservation with 80% survival rates; and the recovered cultures maintained their somatic embryogenic capacity.