Plant regeneration from protoplasts of mango (Mangifera indica L.) through somatic embryogenesis

This report describes a protocol for the regeneration of plants from protoplasts isolated from proembryogenic masses (PEMs) in a suspension culture derived from the nucellar callus of mango (Mangifera indica L. cv 'Amrapali'). The maximum yield (24.6±1.1×10⁶), with 81.04±4.1% viable protoplasts per gram PEMs, was obtained with an enzyme mixture containing 1.2% cellulase, 1.0% hemicellulase and 0.6% pectinase. An optimum density of 5×10⁴ cultured protoplasts per milliliter culture medium was required for the highest frequency (88.89±5.40%) of division. Dividing protoplasts developed into microcalli that proliferated on medium supplemented with growth regulators (auxins or kinetin alone, or auxins with kinetin) and produced somatic embryos after transfer to a growth regulator-free medium. The protocallus on 2,4-D-containing medium produced the maximum number (102.50±6.93) of somatic embryos. Maturation of somatic embryos depended upon the presence, and the nature and combination of growth regulators in the medium during proliferation of the callus. The mature somatic embryos germinated and developed into plants that were transferred to soil.