Germination capacity and viability of threatened species collections in seed banks

Abstract

Facing the current biodiversity crisis, the value of ex situ conservation has been increasingly acknowledged in international treaties and legislations. Seed banks are a good way of conserving biodiversity, providing that seeds are of high quality and at maximum viability. However, despite the number of established ex situ facilities, there is little information on seed viability in botanic garden seed banks. This paper analyses the status of the seed collection of the National Botanic Garden of Belgium by determining the germination capacity and viability of seeds that have been stored for 1-26 years. It aims at:(1) ensuring that existing storage conditions provide effective ex situ conservation of threatened species; (2) providing viability data on threatened species; (3) planning future collection and storage efforts for seeds of West European species of conservation value. Results from this study showed that the germination and viability percentages of the 250 tested species reached on average 59 and 79% respectively. Some families typically performed better than others. Within a species, consistent results were not always obtained. Over a quarter of accessions exhibited some degree of dormancy. Considering the current lack of knowledge in seed germination and dormancy of many rare and threatened species, we believe that the quality of a seed collection should be estimated by its viability and not by its germination percentage. This study calls for further research in order to better understand the biology of a range of threatened native species.

Ex situ cultivation entails high risk of seed dormancy loss on short‐lived wild plant species

“…Our results show that seed ageing not only reduces viability of seeds, but can also mask differences in seed dormancy between seed sources. While this is important information for the seed exchange among botanic gardens, seed storage at long‐term conditions has been shown to have only minimal impact on seed viability of orthodox seeds stored 20 years and more (Godefroid et al., ; Offord et al., ; Pérez‐García, González‐Benito, & Gómez‐Campo, ). However, not all seeds behave this way under long‐term storage conditions (see Hay & Probert, ) and more research is needed to identify crucial influences of seed origin on storage behaviour.…”

What can routine germination tests in seed banks tell us about the germination ecology of endemic and protected species?

“…Despite the large number of publications characterizing germination niches of individual species or groups of species (e.g. Baskin and Baskin (1998) and references therein; Luna and Moreno (2010)), the available information is often limited for most rare and threatened species, and specific to certain floras (Crawford et al 2007;Godefroid et al 2010). The Secretariat of the Convention on Biological Diversity (2009) has even highlighted that ex situ conservation is often constrained by the absence and/or limited accessibility of data, tools and technologies.…”

Short storability of Caesalpinia echinata Lam. seeds as a consequence of oxidative processes

“…In situ conservation should be the highest priority to conserve species but the ex situ conservation, for example in seed banks, of threatened or endangered plant species has become a necessary and suitable strategy (Godefroid et al 2010, Khoury et al 2010, Enβlin et al 2011, including C. echinata. However, this conservation strategy depends on the longevity of the seeds as well as the knowledge of the physiology of seed deterioration, including biochemical, physiological or genetic degenerative processes.…”