Abstract Detail

Conservation Biology

Johnson, Timothy R. [1], Kane, Michael E. [1].

Preventing loss of viability during seed storage of Eulophia alta (Orchidaceae).

Orchid preservation is a high conservation priority due to numerous threats to native populations and habitats. Ex situ conservation of orchids is particularly difficult because of the challenge of developing asymbiotic and symbiotic seed germination protocols, growing plants to maturity, acclimatizing seedlings in the field and identifying suitable habitats for reintroductions. Ex situ seed banking is a means of prolonging seed viability and a low cost staple of ex situ conservation. When in situ conservation methods fail or are not feasible, seed banks can hold huge quantities of genetic diversity in relatively small spaces providing an insurance policy against the loss of genotypes or species. Developing reliable seed storage methods for orchids provides time to complete these tasks while limiting the impact on wild populations associated with intensive, habitual seed collection. Orchids are not expected to exhibit recalcitrant seed storage behavior because their minute size and their ability to readily equilibrate to changes in relative humidity (two traits associated with orthodox seed storage behavior). However many tropical species are sensitive to cold storage. We found cold storage sensitivity in Eulophia alta, a terrestrial orchid native to Florida in a nine month study. Storage at -10° resulted in complete loss of viability and germinability within three months. At this temperature, storing seed over silica gel desiccant reduced seed moisture content from 10.8% to 2.5% in this same period and germinability stabilized at 40% after two months storage. Viability and germinability of seeds stored at 10° and 25° with or without desiccant remained near 100% after nine months even as seed MC fell below 5%. Seedling development was also greater in these treatments than in both -10° treatments. These data indicate that loss of viability at sub-zero temperatures is exacerbated by high seed moisture content, but that seeds still exhibit cold sensitivity. Room temperature storage may be a suitable long-term storage method and affordable alternative to cryopreservation for this species.

Broader Impacts:

1 - University of Florida, Environmental Horticulture, PO Box 110675, University of Florida - Gainesville, Gainesville, FL, 32611-0675, USA

Keywords:
Germination
Ex situ conservation
Seed storage
orchid.

Presentation Type: Oral Paper:Papers for Topics
Session: 52
Location: 551A/Convention Center
Date: Wednesday, August 4th, 2010
Time: 10:30 AM
Number: 52002
Abstract ID:57