Abstract
Tree breeding for resistance is often seen as the long-term solution to forest disease problems. However, improved resistance through enhancement of tree´s own resistance mechanisms against pathogenic fungi could have negative, unforeseen effects on other organisms. Endophytic fungi are symbionts inside the trees that usually do not cause visible symptoms, but may protect the trees against environmental stress or natural enemies. The goal of the project is to study if resistance to pathogens is accompanied by lower diversity of endophytes in two forest tree species, European beech and pedunculate oak, i.e. tree species that increasingly suffer from diseases in Southern Sweden. Using culturing and molecular methods (DGGE and pyrosequencing), tissue specific endophyte communities will be compared in leaves, bark and wood of pairs of healthy and diseased trees in each species. The pairs to be compared grow close enough to each other to allow similar natural endophyte inoculum. Disease symptoms will be recorded and quantified, and the levels of defensive phenolic compounds will be measured using HPLC to confirm the difference in tree´s resistance status at cellular level. The main deliverable is new scientific information that will support decisions about strategies of tree resistance breeding and forest restoration in diseased areas. The research is organized as a PhD project to be carried out under supervision of international specialists.
Sweden