Abstract Detail

Conservation Biology

Philpott, Megan [1], Vanhove, Anne Catherine [2], Yorke, Suzanne [2], Pence, Valerie [2].

Collecting exceptional species for ex situ conservation: Unique issues associated with tissue cryopreservation.

Collection protocols for seeds of endangered species bound for seed banks have been greatly improved in recent years by studies integrating factors including inevitable propagule loss, which has led to more effective safeguarding of biodiversity. However, the subset of endangered exceptional species for which seed banking is not feasible requires tissue cryopreservation instead for long-term ex situ conservation. The collection of adequate diversity from the field in these species is affected by some issues of genotype loss unique to cryopreservation which must be addressed to ultimately ensure effective banking. Using an active plant cryobank of endangered exceptional species, we can investigate the challenges affecting tissue collection strategies unique to this subset of exceptional species. Collected tissue samples of these species face two major challenges before they can be considered successfully banked: initiation into tissue culture and survival of the cryopreservation process. In most collections of tissue for micropropagation, there will be loss of some genotypes due to factors like contamination, age of tissue, or inability of the genotype to survive the tissue culture growth conditions used. Even with a well-tested and established protocol in place for a species, we may see some loss of genotypes in the tissue culture initiation process. For the federally endangered exceptional New Mexico species Hedeoma todsenii, for example, a field collection of 100 individual plants from one population resulted in the establishment of 21 thriving plants in tissue culture six months after collection. Even after establishment in tissue culture, genotype-dependent survival after short- and long-term cryopreservation in a single species can show a large range. This can be seen in the federally endangered Florida species Crotalaria avonensis, with survival after long-term (4-16 years) cryopreservation ranging from 0-93% depending on the genotype and banking protocol. In the federally endangered exceptional Hawaiian species, Melicope mucronulata, 13 genotypes were tested on two separate cryopreservation protocols, CREW’s developed protocol for the species, and a citrus cryopreservation protocol developed by the USDA. While about half (n=6) of the genotypes showed similar survival between the two protocols, three genotypes showed higher survival in the CREW protocol, and four showed higher survival in the USDA protocol, indicating a non-negligible amount of genotypic variation in response to cryopreservation. Taking potential losses from these factors into account when collecting tissue from the field for ex situ cryo-storage can lead to greater preserved biodiversity and more effective conservation.

1 - Cincinnati Zoo & Botanical Garden, CREW, 3400 Vine St., Cincinnati, OH, 45220, United States
2 - Cincinnati Zoo & Botanical Garden, CREW, 3400 Vine St., Cincinnati, Ohio, 45220, United States

Keywords:
conservation
ex situ
cryopreservation
Tissue culture
exceptional species.

Presentation Type: Oral Paper
Session: CB2, Conservation Biology 2
Location: Virtual/Virtual
Date: Monday, July 27th, 2020
Time: 12:30 PM
Number: CB2001
Abstract ID:406
Candidate for Awards:None