Embryo excision in Compositae, with implications for combating biodiversity loss

Embryo excision is an effective, under-described means of promoting germination in the sunflower family and may help to ensure the survival of endangered taxa or lineages with limited seed availability.

We describe and illustrate a detailed method of embryo excision used successfully to stimulate germination in a diversity of composites and that requires minimal materials and expense, using Layia platyglossa as an example. We show how this procedure greatly increases germination compared to control treatments in Madia elegans, a close relative of Hawaiian silverswords that exhibits physiological dormancy.

This technique can be learned quickly and is highly effective. Embryo excision can aid conservation efforts dependent on minimal seed resources by enhancing germination and allowing evaluation of seed quality before or after storage, as well as synchronizing seedling development, thereby allowing for refinement of ex situ seed bank conditions and efficient use of horticultural resources.