The potential of thidiazuron in in-vitro propagation of selected ornamental plants

Abstract

The potential of the phenylurea derivative, (N' -phenyl-N' -1 ,2,3-thidiazol-5-ylurea, thidiazuron, TDZ) in stimulating morphogenic responses from shoot-tip cultures of various omamental crops iPolionthes tuberosa L., Alstroemeria aurantiaca cv. Rosita, Ornithogalutn saundersiae, and Dial/thus caryopliillus L. cv. Yair), when compared with a combination of auxin and cytokinin was investigated. Whole plant regeneration was achieved from shoot-tip explants in all the crops tested either directly or indirectly (via an intervening callus phase). In camation, Ornitltogalum, and tuberose, TDZ induced morphogenic responses with an efficacy higher than a combination of KIN+NAA, BA+NAA, and BAP+NAA, respectively. TDZ promoted a comparable morphogenic response to that of a combination of BAP and NAA in Alstroemeria. In addition, the effect of various concentrations of TDZ (0.1, 0.4, 1.0, and 5.0J.lM), applied for various durations (3, 10, 24, and >40 days) was determined in camation shoot-tip cultures. Higher TDZ concentration (5.0J.lM), compared to 0.1, 0.4 and 1.0~lM applied for a short duration (3 days) was found to be optimum culture conditions for the in- vitro regeneration of plant lets. The ability ofTDZ to substitute for auxin and cytokinin requirement, further suggests its role in modulating endogenous growth substances. Overall, thidiazuron was more potent or equally potent in inducing morphogenic responses in -vitro in the selected ornamental crops.