Understanding and improving the conservation of the intraspecific variation of imperiled plants in ex situ collections

The representation of intraspecific variation of a plant species in ex situ collections is a major issue that has often been addressed by employing general collection guidelines, based on principles of population genetics, meant to be applicable to a wide range of plant species in the absence of genetic information. Recent studies show, however, that in some cases these general guidelines perform poorly. In this presentation, I will describe a recently funded IMLS project that explores an alternative approach to this issue, which emphasizes species-specific estimates of genetic and phenotypic variation, while taking advantage of resources present in botanical gardens. Like many other botanical gardens, the Missouri Botanical Garden (MBG), is constantly improving our capacity to generate and analyze plant genomic data. Likewise, MBG and many botanical gardens manage ex situ collections in ways that are de facto common garden experiments, a well-established method to study heritable phenotypic variation. Building on these resources, we are developing a model that botanical gardens may broadly adopt to assess intraspecific variation in plants and efficiently represent it in ex situ collections. We focus on six priority plant species of conservation concern in the ex situ conservation program at MBG, representing a diverse array of plant life-histories, geographic ranges, and curation challenges in botanical garden collections. In each species, we are measuring adaptive and neutral intraspecific variation, both in genotypes and phenotypes to design ex situ collections that maximize the representation of different kinds of intraspecific variation under real-life limitations of living collections. The results of this project will help answer a pressing question in conservation biology: the degree to which neutral and adaptive variation, both in phenotypes and genotypes, are uncoupled in rare species, and how that may affect ex situ conservation strategies.