The effect of cytokinins in vitro on the growth and development of Elatior begonias (Begonia Elatior-hybr.)

Authors

• Päivi Roivainen Department of Horticulture, University of Helsinki, SF-00710 Helsinki

DOI: https://doi.org/10.23986/afsci.72401

Abstract

Micropropagation involves the risk of somaclonal variation among the regenerated plants. It is possible that the components of the nutrient medium, especially growth substances, increase the frequency of variation. Elatior Begonia 'Barbara' plants were micropropagatedusing four cytokinins (zeatin 0.5—2.0 mg/l, kinetin 0.5—2.0 mg/l, IPA 0.5—2.0 mg/l or BAP 0.05—0.65 mg/l) in vitro. The number of shoots produced per explant and the subsequent quality of full-sized, flowering plants were studied. In general, the number of big (> 1 cm) and medium-sized (0.5 —1.0 cm) shoots decreased and the number of small (<0.5 cm) shoots increased with increasing cytokinin concentration. The survival rate after transfer in vivo was highest among big shoots (97 %) and lowest among small shoots (65 %). Variation in the development time and number of branches, flowers and flowerbuds was observed among plants induced with different cytokinins at different concentrations. The shortest development time, the lowest number of branches and the highest number of flowers and flowerbuds ( = best quality) were obtained with 0.5 mg/l kinetin.