Plant regeneration through direct somatic embryogenesis from protoplasts of banana (Musa spp.)

We report the isolation and regeneration of protoplasts from an embryogenic banana (Musa spp.) cell suspension culture initiated from in vitro proliferating meristems. A high yielding isolation method (up to 6×10(7) protoplasts.ml(-1) packed cells) is discussed. Optimal regeneration, with more than 50% of the protoplasts showing initial cell division, occurred when high inoculation densities (10(6) protoplasts.ml(-1)) or nurse cultures were applied. Under these conditions, the frequency of microcolony formation was 20-40%. These microcolonies developed directly, without an intervening callus phase, into somatic embryos which later germinated and formed plantlets.