Plant regeneration from cultured protoplasts of Moricandia nitens

A protoplast culture procedure was developed for the wild species Moricandia nitens that is a C-3-C-4 intermediate with a close relationship to Brassica species. Protoplasts derived from leaf mesophyll, grown on B5 medium, were cultured at a density of 1 x 10(5) ml(-1) in modified KM8p medium supplemented with 0.5 mg l(-1) BA, 1.0 mg l(-1) 2,4-D and 0.1 mg l(-1) alpha-NAA. After 3 w of culture in the dark, microcalli were plated on an amplification medium in dim light. Calli larger than 3 mm in diameter were transferred to the regeneration medium in light. Twenty-three percent of the calli could regenerate plants from the media using a range of growth regulator combinations. Two or more shoots often grew from one callus. The procedure allowed hundreds of plantlets to develop from protoplast culture within a period of 10 w. This practical system provides the opportunity to transfer the C-3-C-4 intermediate character to Brassica crops via somatic hybridization.