High-frequency regeneration and transformation ofRaphanus savus

Abstract

We have achieved high-frequency shoot regeneration in radish(Raphanus sativus). Cotyledon explants from four-day-old seedlings were suitable for the effective induction of shoots on Murashige and Skoog’s (MS) medium containing 3.0 mg/L kinetin. We also determined that it was essential to include 1- to 2-ram petiole segments with the cotyledons for efficient induction. When the regenerated shoots were transferred to an MS liquid medium containing 0.1 mg/L NAA, roots formed within four weeks, and normal plant development ensued. We established a transformation protocol using anAgrobacterium binary vector that carries the GUS reporter gene. Preculturing the explants for I d in an MS medium containing 3.0 mg/L kinetin also increased efficiency. Five days of cocultivation proved best for delivering T-DNA into radish. Transformation frequencies of up to 52% were obtained in shoot induction media that contained 3.0 mg/L kinetin.