Okubo H. et al. 1991

• Authors: Okubo H.; Wada K.; Uemoto S.
• Title: In vitro morphogenetic response and distribution of endogenous plant hormones in hypocotyl segments of snapdragon (Antirrhinum majus L.)
• Location: Plant Cell Reports 10: 501-504 (1991).
• Abstract: Snapdragon seedlings, 20 mm in length, were cut into 5 segments fron the cotyledon to the root, which were cultured in vitro on hormone-free MS medium. Adventitious shoot formation was highest in the basal hypocotyl segments with stimulation by the addition of BA. Endogenous cytokinins were higher in the baseal hypocotyl segments, whereas auxin content was higher in the two upper than in the basal hypocotyl segments. Ratios of cytokinins to auxin were also the highest in the basal hypocotyl segment. A general principle in in vitro culture that a high concentration of cytokinin and a low concentration of auxin promotes the induction of shoot morphogenesis was confirmed from measurements of endogenous growth regulator concentrations.