Highly efficient induction of sugar beet plant regeneration.

A method for high-frequency in vitro regeneration of adventitious shoots from petiole explants of a tetraploid breeding line 405 of Beta vulgaris L. was established. Plant regeneration was obtained by direct bud formation from petioles. Explants were precultured in a medium containing MS inorganic salts supplemented with Gamborg's vitamins, named MSB. Adventitious shoots were developed when petiole explants excised from 20-30-day-old seedlings grown on MSB containing 0.3 mg/L naphthalene acetic acid (NAA), 1.0 mg/L 6-benzylaminopurine (BA), and were then cultured on MS with 0.3 mg/L NAA and 1.0 mg/L BA. Shoots rooted on half-strength MS medium containing 0.5-1.0 mg/L NAA. This procedure of the culture method may be very useful both for multiplication of sugar beet and for the introduction of foreign genes into Beta vulgaris. The proliferation rate of induced plantlets is as high as 51.3%.