Brighamia insignis

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.

Contributing Author(s): 
Date Recorded: 
Thursday, May 2, 2019

Jordan Wood, Jeremie Fant, Andrea Kramer and Kay Havens, Chicago Botanic Garden

Genetics becomes important whenever populations become small (<100). This includes loss o fgenetic diversity from drift, increased expression of deleterious genes due to inbreeding, and limiting local adaptation. Since many species of plants are able to be seed banked, it is possible to maintain numbers well above these critical genetic thresholds. However for exceptional species, which can only be maintained as living plants, or for critically endangered species where remaining individuals are already below these numbers, the need to consider the remaining genetic diversity becomes critical. Importantly, the management focus shifts from saving a population to preserving each genetically unique individual. When you have such small numbers, it is critical to know how each individual contributes to the overall genetic diversity remaining. We are working with National Tropical Botanic Gardens (Hawaiʻi) to develop a multi-institution species management and breeding plan for Ālula(Brighamia insignis)that will ultimately support its restoration to the wild. To do this we are working with scientists at the Chicago Zoological Society to modify management software that incorporates genetics and demography information to maintain the long-term health of their captive populations of animals over the long term. Through this case study, we hope to develop collections management practices for plants that preserve important genetic diversity while identifying genetically appropriate individuals to using in crosses and that can ultimately be used to create resilient populations that can be used in reintroductions.

Contributing Author(s): 
Date Recorded: 
Friday, May 4, 2018