In vitro bulblet production of Brunsvigia undulata from twin-scales

Many South African medicinal plants are over-collected for use in traditional medicines. This necessitates developing methods for increasing production. Micropropagation can be used as an alternative to conventional propagation methods. Twin-scales, cut from large parent bulbs, were cultured on MS medium (Murashige and Skoog, 1962) supplemented with 25 plant growth regulator combinations. Bulblets formed on twin-scales in 24 of the treatments. All explants formed bulblets on plant growth regulator-free medium. The effect of plant growth regulators, activated charcoal, explant orientation, explant origin and photoperiod on bulblet production was investigated. Bulblet formation was greatest when twin-scales were excised from the middle of the parent bulb, placed adaxial side down on plant growth regulator-free medium and kept in a 16 h photoperiod.

Research Highlights
► Plant growth regulators are not required for normal bulblet development from twin-scales of Brunsvigia undulata.
► Twin-scales from Brunsvigia undulata must be placed adaxial side down on medium for bulblets to develop. If placed upright or abaxial side down on the medium, no growth or development occurs.
► Twin-scales excised from the middle scales of the parent bulb are most productive in vitro.