Welwitschia mirabilis-Induction, Growth and Organization of Mature Leaf Callus

Welwitschia mirabilis is a phylogenetically important primitive gymnosperm of the monogeneric family Welwitschiaceae. The plant is unique in appearance, having only two leaves throughout its life span. It is a long-lived, slow growing plant and could prove as an excellent experimental material for the study of antiageing gene. Because of non-availability of plant material and the intractable nature of the plant, limited tissue culture work has been conducted. In the present study, callus was induced from mature leaf-tip explants from a 26-year-old plant. The induced callus grows at a comparatively faster pace. Although successful induction of organized shiny and smooth, globular structures were observed, no shoots had developed in the callus.