A simple culture method for Brassica hypototyl protoplasts.

Hypocotyl protoplasts from oil rape, Brassica napus L. cv. Isuzu were cultured in the dark at 25°C in a modified Nitsch and Nitsch medium containing 13% sucrose, 5 g/l Ficoll, 0.5 mg/l BAP, 1 mg/l NAA and 0.5 mg/l 2-4 D. Protoplasts floated on the surface of the medium and developed into microcolonies 0.5 mm in diameter in 4-6 weeks. The microcolonies also remained on the surface of the medium. Transfer to MS medium supplemented with 200 mg/l casein hydrolysate, 5mg/l BAP, 0.5 mg/l NAA and solidified with 0.6% agarose induced shoot regeneration in 3-4 weeks.