The biodiversity of nature and landscapes has been on the decline for years, making it vital to conserve indigenous gene resources of those trees and shrubs which are still available. The conservation of genetic diversity is crucial for the resilience of forests, adaptation to climate change and variation in the landscape.
A provenance trial full of wild cherries is located in the Flevopolder. Here, the Centre for Genetic Resources, the Netherlands (CGN) tests the adaptability of seed sources from the Netherlands, Belgium, Germany, France and UK to Dutch conditions as well as their growth capacity, wood quality and health. Wild cherry is one of the many tree species of which CGN collects information in these tests. Another example involves an international beech test. CGN performs this research for the National List of Varieties and Provenances of Trees to advise users in choosing forest reproductive material.
Genetic characterisation with SNPs
CGN uses DNA research to analyse the genetic diversity in the collections. SNP genotyping is deployed to further characterise genetic diversity in the genebank collections and optimise the collections. One of the issues studied for the wild apple collection is whether hybrids exist with the cultivated apple.
In situ conservation
CGN supports and stimulates both in situ (original location) and ex situ (genebank) conservation of the genetic diversity of indigenous trees and shrubs. The conservation of genetic diversity is coordinated within a European framework (EUFORGEN).
The EUFGIS database provides information on the ‘gene conservation units’ assigned by the countries involved. These locations are where important populations of (indigenous) trees and shrubs grow and where they grew originally.
Ex situ conservation: the genebank
CGN also scientifically supports the genebank (ex situ conservation) which contains over 50 indigenous species of trees and shrubs and 4790 accessions that originally grow in the Netherlands and of which the indigenous gene resources are at risk. Among others, the genebank includes hawthorn, white elm, black poplar, small-leaved lime, gooseberry and wild apple. We support Staatsbosbeheer, the Dutch government organisation for forestry and nature reserves, in the build-up, maintenance and optimisation of the collections and further expansion with additional accessions. DNA markers are used to characterise the genetic diversity and relations between materials in order to advise Staatsbosbeheer on the possible separation or combination of populations and individuals.
‘New’ tree species
In addition to well-known forest tree species, interesting ‘new’ species are available for the development of future forests such as the walnut and Turkish hazel. Although they may be of interest for use in the Netherlands for their ability to respond to climate change, there is an increased risk of frost damage. To assess this, CGN has two field tests with nut species, including their hybrids.