Dierama luteoalbidum: Liquid culture provides an efficient system for the ex situ conservation of an endangered and horticulturally valuable plant

AbstractAn efficient and reliable protocol for the in vitro propagation of Dierama luteoalbidum, an endangered and horticulturally important plant is described. D. luteoalbidum seeds were germinated in vitro on full-strength solid (Murashige and Skoog, 1962) medium following decontamination. Hypocotyl explants obtained from the seedlings formed multiple shoots on MS medium supplemented with 0.5 mg L−1 BA (4 shoots being initiated per explant) while an increase in the BA concentration (1–2 m gL−1) and addition of NAA (1 mg L−1) increased the incidence of callus. After 6–8 weeks, shoots were reduced to meristemoids when transferred to a liquid-shake MS medium supplemented with 0.5 mg L−1 BA for mass propagation. These formed secondary shoots after 3–4 weeks on solid MS medium containing 0.5 mg L−1 BA. Rooting of the plantlets occurred readily but was significantly promoted by adding 6–8% sucrose. Shoots left undisturbed on the same medium for 6 months responded by forming corms. The addition of paclobutrazol (5–10 mg L−1) reduced the corm induction period to 3 months. Microplants transferred to a peat: compost: bark mixture (1:1:1) (v/v/v) in the greenhouse had a survival rate of 100%. All acclimatized plantlets formed corms after 6 months following the application of 1% (v/v) Kelpak — a seaweed concentrate