Abstract Detail

Ecology

Seglias, Alexandra [1], Kramer, Andrea [2].

The effects of frozen storage on seed dormancy and germination patterns of native southwestern forb species.

Plant biodiversity is being lost at an unprecedented rate. In order to conserve plant species, many institutions are turning towards ex situ conservation when in situ conservation is not feasible or sufficient for the long-term. Frozen seed banks have become a primary method of ex situ conservation of many plant species worldwide, and are increasingly used to restore or reintroduce native plant populations. However, frozen storage conditions may alter dormancy and germination patterns, which could change how they should be utilized in restoration or reintroduction settings. While extensive research exists on the subject of seed viability in frozen storage, significantly less is known about the impacts of frozen storage on dormancy and germination. For example, frozen storage may alter the depth of dormancy and affect germination timing. To examine the influence of frozen storage on dormancy and germination, we used frozen and non-frozen seeds from populations of six native, restoration-relevant forb species from the Southwest U.S. Seeds were dried to 15% rH and stored in the seed bank freezer (-20°C) at Chicago Botanic Garden for at least 3 months. Frozen and fresh seeds were subjected to three stratification temperatures, six stratification lengths, and two incubation temperatures to closely examine dormancy break and germination under many conditions. We analyzed germination during stratification and final germination proportion using generalized linear models, and germination rate using survival analysis. We found that storage significantly explained final germination for two species and significantly explained germination during stratification for four species. Results differed among species and treatments, and in some instances we found that frozen seeds germinated to higher proportions than non-frozen seeds. Furthermore, storage alone did not significantly predict germination rate for any species, but did significantly interact with stratification length to explain germination in four of the six species. Implications of these results, and potential applications to restoration and ex situ conservation will be discussed.

1 - Denver Botanic Gardens, 909 York Street, Denver, CO, 80206, United States
2 - Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, IL, 60022, United States

Keywords:
Seed Germination
seed bank
restoration
frozen storage.

Presentation Type: Oral Paper
Session: 14, Ecology Section - Reproductive Biology
Location: 106/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 2:00 PM
Number: 14003
Abstract ID:599
Candidate for Awards:None