[COLLOQUE] GENTREE Final Conference 27-31 January 2020 séance 18

GENTREE Final Conference : Sean HOBAN - The Morton Arboretum Lisle · USA

GENTREE Final Conference 'Genetics to the rescue - managing forests sustainably in a changing environment'

27-31 January 2020, Avignon, France

http://www.gentree-h2020.eu/

Sean HOBAN - The Morton Arboretum Lisle · USA : Conserving genetic diversity in botanic gardens: calculating how much to conserve

Ex situ collections such as botanic gardens inspire and educate the public, provide material for scientific study, and produce material for ecological restoration.

The challenge for an efficient and effective collection is safeguarding high genetic and ecological diversity in as few samples as possible, due to the relatively small resources available for conservation.

A botanic garden might haveresources to maintain a few to a few hundred plants of priority species in conservation collections, but not the thousands that seed banks can preserve.

Providing scientifically grounded recommendationsfor the number of individuals that need to be conserved, and how tocollect from the wild and manage collections over time, is a pressingneed.

Previous work using case studies and modeling of importantbiological traits has established the fact that some species must besampled differently, and that widely used standard sample sizes mightnot be optimal practice for capturing diversity.

We present here acomparative study of ex situ gene conservation in 11 species acrossfive genera (oaks, magnolias, cycads, palms and hibiscus).

Specifically, we use genetic datasets and resampling algorithms to:quantify how much genetic diversity has been captured in a globalnetwork of botanic garden collections currently; resample the wildpopulation genetic datasets to determine how much genetic diversitycould be captured by varying sample sizes; and use a diminishingreturns method to calculate optimal stopping points- when additionalcollection effort no longer provides sufficient gains.

Between 28 and95% of genetic diversity is currently safeguarded.

Even under anoptimistic assumption only eight of the eleven species meet the 70%genetic diversity Target of the Global Strategy for PlantConservation.

The recommended collection size depends on biologicalfactors as well as (a previously underappreciated factor) keydecisions by curators about the type of genetic diversity that isvalued, but may range from approximately 50 to 200 individuals.

Wehope that these findings motivate future seed collections from wildprovenances for botanic garden collections and stimulate discussionon ex situ gene conservation goals and outcomes