FraxGen SP6 - Identification of differentially expressed genes (DEGs) in response to ash dieback in Fraxinus excelsior (09/2020 – 08/2023)
Project leader: Prof. Oliver Gailing

Postdoc researchers: Renata Callegari Ferrari, Ph.D., Dr. Katharina Budde

Funding: Federal Ministry of Food and Agriculture
There is an ongoing concern about the vast decline of ash (Fraxinus excelsior) especially in European forests due to ash dieback fungus (Hymenoscyphus fraxineus ) attack. The damages caused by the fungus range from crown and wood damage to tree death. To address the threat of ultimately losing the species in the German forest ecosystem, a large scale project “FraxForFuture” was established with a mandate of “long-term preservation of the ash as an economic tree species”, of which the FraxGen SP6 is part of. Based on both natural populations and experimental trials, some ash trees have shown more tolerance to the disease than others. However, in the natural populations, only a small percentage of ash shows tolerance to the disease. Furthermore, in the natural setting, it is neither practical nor efficient to monitor all natural infection and tolerance potential of trees starting from their early stages of life. Therefore, the main objective of this project is to develop SNP markers for the screening, selection and breeding of Ash tolerant trees in Germany.
In the first step, susceptible and tolerant genotypes are identified in natural populations and monitored in controlled setting by the project partners in different parts of Germany. The two contrasting genotypes are grafted and infected with the fungus and then used to conduct a genome-wide gene expression analysis in order to identify DEGs in response to the ash dieback. Using the DEGs, single nucleotide polymorphism (SNP) markers will be identified and selected. In the next step, the SNP markers are validated in natural populations with varying levels of tolerance/susceptibility to ash dieback.