Production of Solanum nigrum and S. nigrum var . judaicum plants with a high power of alkaloid accumulation was the aim of in vitro regeneration trials followed by in vivo plant acclimatization. MS-basal medium containing BA and NAA (0.5 mg/ml each) was the best for both plants. A series of in vitro and in vivo plants were successfully produced and chemical analysis revealed contents of glycoalkaloids higher than those reported for intact field plants. (C) 1999 Elsevier Science B.V. All rights reserved.