New approaches for conservation of threatened elm trees through holobiont concept

Elm trees (Ulmus spp.) are threatened by an aggressive fungal disease, Dutch elm disease (DED) throughout their distribution area. Because of DED, native elms are classified as Critically Endangered in the Swedish Red List. Elms host rich biodiversity, including internal (endophytic) fungal communities and epiphytic lichens and mosses.

Thus, the mortality of elms in the forests will have significant consequences for ecological sustainability. The loss of native elms is also a problem in urban areas where the elms are a valued part of the green infrastructure.

Recently, a national effort was initiated in Sweden to develop a long-term strategy for the conservation of elms through breeding. The proposed project adheres to this initiative.

Using the recently emerged holobiont concept as a theoretical framework (i.e., considering that plants and their associated microbes are a functional and evolutive unit), the project explores the potential connections between the DED resistance and composition of associated fungal communities in elms.

It will also examine the consequences of vaccination treatment on the associated fungal and lichen biodiversity and assist the resistance tests needed in future breeding efforts by characterizing the northern pathogen population. Visits to expert collaborators organizations will support the project and career development of the applicant.

A focused and target group-oriented communication strategy will ensure efficient transfer of knowledge.