Epsilon Archive for Student Projects

Abstract

This research investigates the long-term viability of seeds stored under ultra-dry conditions, which
involves reducing seed moisture content to levels below conventional seed bank standards. The
study is conducted within the context of ex-situ plant conservation of native Hawaiian species. The
germination rates of ultra-dry and conventionally dried seed samples were analyzed by extracting
more than 20 years of data from routine viability tests. A comparative analysis was performed to
evaluate if ultra-dry seed storage has an effect on viability over time. Mixed-effects models were
employed in the statistical analysis and applied separately according to seeds’ storage behaviors.
Relative humidity was measured inside glass vials and laminated aluminum foil packets used for
long-term seed storage. The results suggested no significant differences in germination rates
between the two desiccation methods. Hygrometer measurements revealed that seeds’ relative
humidity in storage is not reaching the expected value and seeds are, in fact, usually stored more
humid than intended. The differences in recorded relative humidity may be attributed to the
desiccation protocol, storage methods (containers and temperatures), and seeds’ chemical
properties. This research shows that seeds could maintain long-term viability (longevity) in storage,
regardless of RH treatment. It also suggests that drying seeds below generally accepted levels may
not be deleterious to longevity.