In vitro propagation of Eucomis L'Hérit species - plants with medicinal and horticultural potential

Abstract

Eucomis (Family Hyacinthaceae) are deciduousgeophytes with long, narrow leaves and erect, densely packed flower spikes. Thebulbs are greatly valued in traditional medicine for the treatment of a variety ofailments, and are thus heavily harvested for trade in South Africa's traditional herbal markets. Eucomis species propagaterelatively slowly from offsets and seed, and this, together with theirover-utilisation ethnopharmacologically, has led to their threatened status. Thein vitro propagation of the genusEucomis was investigated to optimise this technique for thebulk production of plants for commercial and conservation purposes. Multipleshoot production was initiated from leaf explants, in all species studied. AMurashige and Skoog (MS) medium, supplemented with 100mg amp;ell;−1 myo-inositol, 20g amp;ell;−1 sucrose, and solidified with 2g amp;ell;−1 Gelrite® was used. Theoptimal hormone combination for shoot initiation in the majority of species was1 mg amp;ell;−1 NAA and 1mg amp;ell;−1 BA. Optimal root initiation wasdemonstrated on media supplemented with 1mg amp;ell;−1 IAA, IBA or NAA, depending onspecies. A continuous culture system using this protocol produced 25–30plantlets per culture bottle, with 10–25 specimens per bottle availablefor acclimatisation. To maximise plantlet survival, different support media usedduring the acclimatisation process were necessary. Certain species respondedbest on a vermiculite medium, while perlite (which holds less water) wasnecessary for the optimal survival rate of other species. Acclimatised plantletswere repotted in a sand: soil mix (1:1).