Comparison of Three Cryotechniques for Conservation of Banana (Musa AAA, Cavendish Subgroup) Genotypes

The aim of this study was to compare three cryotechniques, namely, droplet vitrification (DV), vitrification-cryo-plate (VCP) and dehydration-cryo-plate (DCP) on proliferating meristems of two Musa (AAA, Cavendish Subgroup) genotypes. The experiment was set up as factorial completely randomized design for the two Musa accessions (IC 250462 cv ‘Borjahaji’ and EC 493718 cv ‘Williams’) in five different dehydration duration (30 -150 min). Regrowth after cryopreservation in all treatments was predominantly of two types - shoot regeneration and callusing. In both the cultivars, shoot regrowth of non-frozen and LN treated meristems were not impacted significantly by duration of dehydration exposure, however, callus growth was significantly different with increasing time of exposure. The mean shoot regrowth for all dehydration treatments in Borjahaji was not significantly different. However, the VCP method in Williams, with mean shoot regrowth of 75.5 ± 2.8% was found to be significantly (P<0.05) better than that obtained from DV (63.1 ± 2.5%) and DCP (64.8 ± 1.9%). Quantitatively, highest shoot regrowth was obtained after 120 min PVS2 exposure in both cultivars, but using VCP method in Williams (86.7 ± 7.7%) and DV method in Borjahaji (73.1 ± 2.7%). Taking into consideration practical aspects for each technique, any of the three cryopreservation approaches can be used for cryobanking of proliferation meristems of Musa, as DV offers cost-effectiveness, while VCP and DCP have ease of explant handling, and DCP avoids chemical toxicity of PVS2.