Conservation Collection

Sean Hoban, Emma Spence, and Patrick Thompson, The Morton Arboretum

The Morton Arboretum seeks to improve the conservation value and genetic representation in ex situ collections by developing guidance for sampling seed. One example regards IUCN Critically Endangered Quercus boyntonii (Boynton sand post oak), which is endemic to Alabama and only occurs on exposed sandstone outcrops.In situ threats include overcrowding by invasive species, off trail disturbance by humans, and the threat of wildfires. To help safeguard this species in case wild populations are lost, we compared genetic diversity of wild Quercus boyntonii populations to ex situ collections. We collected 246 individuals from 11 locations in the wild and 77 samples from 14 botanic gardens across the United States. We used microsatellite DNA markers to quantify genetic variation existing in the wild samples and calculate the proportion of genetic variation that exists in ex situ collections. This is a direct measure of the success of the collective efforts to build conservation collections. We found that current ex situ collections capture approximately 78% of overallgenetic diversity, and 100% of common alleles. We also used a resampling technique to determine how efficient this collection is, and we showed that a smallerex situcollection may be sufficient if it is carefully planned. The overall message is that ex situ collections of a taxon spread across a number of institutions can safeguard a species’ genetic diversity. This work is part of a large, multi-institution project in which genetic variation in ex situ collections of 10 species will be quantified. Our end goal is to provide advice to the garden community about how to establish and maintain ex situ tree collections, which includes initiatives to distribute germplasm collaboratively.

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

Heather Schneider, Santa Barbara Botanic Garden

Conservation seed collections support species’ survival by acting as an insurance policy in the face of extinction. They can also provide resources for research, restoration and reintroduction. A high-quality conservation seed collection has both depth and breadth – capturing genetic diversity within and geographic diversity among populations. Collecting and storing seeds by maternal line (i.e., seeds from a single individual plant represent one maternal line) provides depth to conservation collections. Previous research has suggested that collecting from 50 maternal lines throughout the geographic extent of a given population increases the odds of capturing the majority of the genetic diversity within that population. Capturing the maximum amount of genetic diversity possible from each population increases the integrity of a conservation collection. Further, keeping maternal lines separate ensures that each line can be equally represented in restoration and reintroduction efforts. Separating seeds by maternal line also creates opportunities for future research, especially when questions center on genetic differences within and between populations. When bulk collections are made, there is only a small chance that each maternal line will be represented when a subsample of the collection is removed for use and valuable information is lost. Although collecting by maternal lines makes seed collection and cleaning more complicated, the amount of information that is retained increases the value of the collection and makes the effort worthwhile.

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

Is it possible to designate multi-institution Conservation Groves when many institutions have a few wild provenance individuals of the same species?

For California Plant Rescue, we are conducting a gap analysis of the conservation collections of California native plants by compiling the "living collections" and seed accessions of six botanic gardens. There are a few instances where living collections clearly represent intentional, population level conservation collections at a single institution.

Christa Horn and Joyce Maschinski, San Diego Zoo Global and Center for Plant Conservation

The primary purpose of a conservation collection is to support species’ survival and reduce the extinction risk of globally and/or regionally rare species. A conservation collection is an ex situ (offsite) collection of seeds, plant tissues, or whole plants that has accurate records of provenance, maternal lines differentiated, and diverse genetic representation of a species’ wild populations. To be most useful for species survival in the wild, a conservation collection should have depth, meaning that it contains seeds, tissues or whole plants of at least 50 unrelated mother plants, and breadth, meaning it consists of accessions from multiple populations across the range of the species. Conservation collections of seeds should have tests of initial germination and viability, cultivation protocols developed, and periodic testing of long-term viability.

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