Two decades of climate change alters seed longevity in an alpine herb: implications for ex situ seed conservation

Abstract

Climate warming in mountain areas is increasing faster than the global average, threatening alpine plants. Climate affects many traits including seeds, the longevity of which is important for conservation, facilitating genebank storage. Seeds of alpine species are considered short-lived in storage, but their longevity increases when produced under a warmer parental environment. Consequently, with climate warming, seeds of alpine species may have increased fitness and be longer-lived in genebank storage. We assessed seed longevity under artificial ageing in 10 accessions of the arctic-alpine species Viscaria alpina stored under genebank conditions for different time periods over the last 20 years. The seed collection site was in the northern Apennines, where above average warming and variable precipitation has been recorded. The time taken for viability to fall to 50% (p₅₀) was estimated using probit analysis; correlation and general linear regression were used to investigate the effects of length of time in storage, seed mass and climate under which seeds were produced on seed longevity. p₅₀ varied between 7.77 and 18.49 days. There was no relationship between length of time in storage or seed mass on seed longevity. p₅₀ was higher in years with increased temperature and lower precipitation during the growing season, with precipitation having more impact than temperature. The results suggest that seeds of alpine species are suitable for genebank storage, and inter-annual variation in precipitation induces a plastic response in seed longevity. Using genebank stored seeds provides insights into how alpine species may respond to future climate changes and could have implications for genebank storage.