Establishment of embryogenic cell suspensions and plant regeneration of the dessert banana ‘Williams’ (Musa AAA group)

Abstract

Summary‘Williams’ is one of the most important dessert banana cultivars in the World. Improvement through genetic engineering depends on the development of embryogenic cell suspension (ECS) cultures. Yellow, compact meristematic globules and yellow-whiteish, friable embryogenic calli were induced from scalps (i.e., the top layer of highly proliferating meristem cultures). About 10% of induced explants gave rise to embryogenic calli. Embryogenic calli were used subsequently to establish ECS cultures. After 3 months of selection and sub-culturing, homogeneous ECS cultures with a high regeneration capacity were obtained. More than 80% of the cell culture consisted of embryogenic cell aggregates. Regenerable somatic embryos emerged about 3 weeks after the ECS was plated onto regeneration medium. Their weight increased 4.8- to 13-fold after 8 weeks of culture. The number of somatic embryos regenerated per ml settled cell volume (SCV) of embryogenic cells (i.e., somatic embryo recovery frequency) ranged between 0.92 – 2.17 105, depending on incubation and regeneration conditions. The conversion frequency from somatic embryo to plant varied between 42.5 – 55.5%, and was independent of regeneration conditions.