Conventional and unconventional propagation methods, including tissue culture and shoot tip culture.
Many of the species grown at Nasami Farm are difficult to propagate by
conventional methods. Some have strong inhibitors in their seeds that prevent
them from germinating; others simply do not produce roots rendering cutting
propagation useless. Quite often, these are the most sought after species since
everyone finds them difficult to propagate. With these troublesome species, we
have taken them to the laboratory.
Tissue culture, or
micropropagation, is a fascinating process in which plant tissue is cultured on
a nutrient rich gel media in sterile conditions. Single cells of leaf tissue can
regenerate whole plants, as can shoot tips, leaf pieces, root pieces, lateral
buds, or stem sections.
Shoot Tip Culture
Shoot tip culture is the method in widest use for the mass propagation of woody species. An actively growing shoot tip is surface sterilized and placed on a defined culture medium under sterile conditions. The culture medium contains inorganic and organic salts (macronutrients, micronutrients and vitamins) as well as an energy source (sucrose or table sugar), growth regulators, and agar to gel the medium. If the growth regulators are appropriately balanced, the shoot tip elongates, lateral buds break and begin growth, and adventitious shoots are also produced on the stem piece. This rapid proliferation of shoots results in masses of shoots being produced from a single shoot tip. Up to a hundred shoots may be produced in as little as eight to twelve weeks from a single tip. The result of all these transfers is very uniform small plants that can be easily grown on into sizes that can be sold in the nursery.