ElmAsh Research Project

Investigating rapid multiplication techniques and the microbiome of Ash (Fraxinus excelsior), along with the genetic conservation of Wych elm (Ulmus glabra) to breed disease-resistant genotypes.

Background

Common ash (Fraxinus excelsior), is one of our most important native tree species comprising approximately 3.8% of the forest cover in Ireland, while Wych elms (Ulmus glabra) were once a dominant tree species.

Both species have an important social, ecological, cultural and economic role in Ireland. However, fungal pathogens like Hymenoscyphus fraxineus and Ophiostoma spp. continue to threaten the existence of Ash and Elms by causing Ash Dieback Disease (ADB) and Dutch Elm Disease (DED), respectively.

Aim and objectives of the project

The primary aim of the ElmAsh project is to develop tolerant Ash genotypes and establish a germplasm collection of Wych elms for the restoration of these two native broadleaf tree species in Ireland.

The main objectives are:

1. Examine and develop rapid multiplication techniques to accelerate breeding for disease-tolerant Ash genotypes.
2. Investigate the endophytic microbiome of Ash trees from Teagasc gene-banks, which are showing a varying level of tolerance to the natural infestation of ADB.
3. Collect and propagate healthy Wych elm plant material for establishing a germplasm collection and breed for DED tolerance.

The project will inspect different breeding methods to induce early flowering, treatments to break seed dormancy and propagation techniques of Ash genotypes that are tolerant to ADB. These can play an essential role in developing both a breeding strategy and increasing clonal mass production.

The comparative microbiome study of tolerant versus susceptible Ash trees could reveal microbes that are capable of suppressing the pathogen, H. fraxineus. The plant-associated microbes adapted to Ash trees are the reservoir for the isolates with antagonistic and biocontrol potential.

The project will also create a pool of antagonistic microbes with established biocontrol abilities against ADB that could potentially be introduced into the germline of susceptible Ash genotypes to become a part of the core seed microbiome.

Additionally, the propagation of Wych elms from rooted cuttings would be helpful to establish a germplasm collection, which will be a rich genetic resource for breeding elms with tolerance to DED. This will be the first step towards the conservation of native elm species in Ireland. Plants from this collection and progenies will be screened against DED in glasshouse conditions to select tolerant genotypes.

Further information

• Dr Dheeraj Rathore, Tree Improvement Researcher
• Report a healthy ash tree 

Funding

The ElmAsh research project is funded by Teagasc under the Walsh Scholarship Programme for four years.