Microshoots encapsulation and plant conversion of Musa sp. cv. 'Grand Naine'

Abstract

Synthetic seed technologies are useful tools for the field delivery of in vitro derived plantlets. In the present study, different encapsulation procedures and their efficacy in the plantlet regeneration using microshoots of banana cv. 'Grand Naine' were evaluated. Two encapsulation systems were evaluated: i) single encapsulation in beads or droplet hardening method; and ii) double layer or hollow beads. The use of different compounds to enhance the capsule conservation and the conversion to plantlets was also evaluated. The conversion capacity was assessed in vitro on water-agar culture medium or in ex vitro conditions with Gerbox® boxes. The single encapsulation system showed 80% conversion. The capsules with MS saline formulation treated with 100mM KNO3 showed 76% conversion. Capsules with 1.5g L-1 activated charcoal, and 0.5g L-1 benomyl sucrose-free capsules showed 75% conversion. The encapsulated and non-encapsulated microshoots exhibited 100% germination in response to MS culture medium, and polyethylene glycol after 10 days of storage at 4°C. Sucrose-free capsules showed significantly higher germination (83.3%) than those sucrose-enriched capsules (56.7%). The ex vitro conversion of encapsulated microshoots was 20% in the Gerbox™. These results indicate the feasibility using synthetic seeds in the large-scale micropropagation of banana cv. 'Grand Naine'.