Plant Regeneration from Hypocotyl Callus of Radish

Callus initiation and growth and plantlet regeneration were studied using eight cultivars of Raphanus sativus L., including six Japanese radishes, one Chinese and one small `Comet' radish. The basal medium was composed of Murashige and Skoog inorganic salts, 2.0 mg myo-inositol/liter, 0.5 mg each of nicotinic acid and pyridoxine·HCl/liter, and 0.1 mg thiamine·HCl/liter, 30 g sucrose and 2 g Gelrite/liter. High callus yields were obtained on basal medium containing (mg·liter -1 ) 0.1 2,4-D and 1.0 BA for two Japanese radishes and 0.1 NAA and 1.0 kinetin for `Comet' radish. Shoots were regenerated from callus by subculturing on basal medium containing 0.1 or 1.0 mg BA/liter and then transferring to basal medium. Rooting occurred on basal medium. Although callus was obtained in all eight cultivars, shoots and plantlets were regenerated only from `Moriguchi', `Nerima Shirinaga', and `Comet'. Chemical names used: 2-(l-naphthyl) acetic acid (NAA); N -(phenylmethyl)-l H -purine-6-amine (BA); 2,4-dichlorophenoxy acetic acid (2,4-D); 6-(furfurylamino)purine (kinetin).