REGENERATION IN ROOT CUTTINGS OF TARAXACUM OFFICINALE I. THE NATURE AND LEVELS OF ENDOGENOUS HORMONES

Abstract

The levels of auxins, cytokinins and gibberellins in extracts of fresh roots of Taraxacum were estimated by bioassay after chromatography. Auxin activity, largely confined to a single zone on chromatograms, had the RF and chromogenic properties of IAA and ranged from 45 to 85 μg kg‐1 fresh weight of roots (in IAA equivalents). Similar auxin activity was found in root diffusates collected in agar gel. Most of the cytokinin activity was present in the zone RF 0.6‐0.8 on chromatograms developed in a n‐butanol: acetic acid: water solvent. The cytokinin was not characterized but its level in kinetin equivalents was in excess of 500 μg kg‐1 fresh weight of roots. Gibberellin activity was of the order of 1 μg kg‐1 in GA3 equivalents. Copyright © 1974, Wiley Blackwell. All rights reserved