Challenges for ex situ collections: partnerships with the zoo community

Jeremie Fant, Chicago Botanic Garden

This talk highlights the Chicago Botanic Garden’s work on adapting zoo conservation approaches for exceptional plant species. Challenges in ex situ conservation include genetic issues that arise from limited numbers of individuals and founders, and husbandry and hybridization issues encountered during the growing out of collections. A significant advantage in plant conservation is that seeds can be collected for a vast majority of plants. One example is the CBG’s Dixon Tallgrass Prairie Seedbank, which has more than 1,700 species and 10,000 accessions. 

Although banking options are more restricted in animal conservation, other approaches used by the zoo community can be adapted to improve success rates in ex situ plant conservation programs. One such approach is pedigree analysis, which shifts focus from high numbers of individuals to equal numbers of founders. The CBG is testing pedigree analysis on several species, as illustrated by work done with Brighamia insignis. The steps include tracking founders by creating a pedigree of collections, calculating relatedness between all individuals, and making management decisions. This method enables researchers to identify genetically valuable individuals across collections, use life span of a species in collections to determine the sample size needed to maintain a collection, and identify crosses needed to increase diversity and improve collection robustness.

One of the next steps planned by the CBG is to identify collection plants less valuable for maintaining genetic diversity, and use them to test restoration techniques. The ultimate goal is to use ex situ collections for restoration of rare species in the field.