Micropropagation of Cynara scolymus L employing cyclodextrins to promote rhizogenesis

This work describes a micropropagation protocol for plants of Cynara scolymus cv. Early French, employing cyclodextrins during the rhizogenesis stage. Shoot apices were established in basic culture medium consisting of Murashige Skoog mineral salts modified by 50% reduction in NH4NO3 and KNO3, Heller's micronutrients, Gamborg's vitamins, 100 mg l(-1) myo-inositol, 30 g l(-1) saccharose and 8.0 g l(-1) agar, supplemented with 1.0 mg l(-1) 6-(gamma,gamma-dimethylallylamino)-purine and 0.1 mg l(-1) naphthalene acetic acid. In the multiplication stage, to achieve a rate of 3 : 1, basic medium was supplemented with 10 mg l(-1) 6-(gamma,gamma-dimethylallylamino)-purine, 2.0 mg l(-1) kinetin, 0.5 mg l(-1) naphthalene acetic acid and 80 mg l(-1) adenine sulphate. The incorporation of alpha- or beta-cyclodextrins to the rhizogenesis medium supplemented with 3 mg l(-1) naphthalene acetic acid, allowed tripling the rooting percentage and doubling the number of differentiated roots per explant compared to medium without cyclodextrins. The exflasking survival rate of the plants was 70%. (C) 2000 Elsevier Science B.V. All rights reserved.