(Photograph = Mammillaria seeds)

Introduction

Generally speaking there are two types of seeds when it comes to storage, orthodox seeds and recalcitrant seeds. Orthodox seeds can be dried and cooled and kept viable for many years.

The Details

Cacti have orthodox seeds. The seeds can last years in the wild, perhaps building a seed bank in the soil that can germinate in good years. Scientists studied some aspects of storing Mammillaria supertexta seeds. The goal was to understand storage so that seeds might be stored in freezers against the horrible possibility that the species could go extinct in the wild.

The seeds were dried at about room temperature with silica gel. Moisture content was reduced from about 16% to about 2.3%, and the seeds were stored for 6 years at ‑20 degrees Celsius (approximately normal freezer temperature).

After six years the seeds were viable and germinated without any negative effects. Now, the goal is to save seeds for longer terms.

Additional Reading: Storage of Mammillaria supertexta Seeds