Journal de la biodiversité et des espèces menacées

Ex-situ Seed Conservation of Endangered Key Tree Cactus (Pilosocereus robinii)

Abstract

Ana Salazar, Joyce Maschinski and Devon Powell

Ex-situ seed collections are fundamental to the conservation of threatened and endangered plant species. We tested whether or not seeds of the U.S. endangered tree cactus, Pilosocereus robinii, withstand orthodox storage conditions of low humidity (25%RH) and freezing temperatures (-20°C). Mean final germination of fresh seeds and seeds stored under low humidity and low temperature for 1 and 28 weeks ranged from 92 to 96%. Mean final germination did not differ significantly across storage conditions. Seed germination rate exhibited small, but significant differences across storage conditions. Seeds stored under dry conditions of low humidity and ambient temperature germinated significantly faster than dry-stored seeds maintained at freezing temperatures and fresh seeds. Because orthodox methods of drying and freezing can be used to store seeds of Pilosocereus robinii, ex-situ seed banking can effectively assist the conservation and regeneration of this endangered species.