Value of bacteria naturally living in Norway spruce to control wood-rot fungi

Picea abies (Norway spruce) is Sweden’s most economically valuable tree, but timber is constantly threatened by wood-rotting fungi of the Heterobasidion annosum s.l. species complex, which usually infects stumps and spreads via roots to other trees.

This project investigates the biocontrol potential of bacteria from the genera Pseudomonas and Sphingomonas, both known to include strains with anti-fungal properties.

In particular, we ask whether “home” strains of these bacteria (that are directly isolated from Norway spruce in Sweden) are better adapted to life in the tree than “away” strains (isolated from unrelated plants, soil, or other foreign sources), and thus may have a “home field advantage” for fighting H. annosum in Norway spruce.

We will characterize “home” and “away” bacterial populations using high resolution genetics to identify signs of adaptation to spruce, and then apply bacterial isolates to spruce seedlings to experimentally test which ones are most successful growing and persisting there.

Finally, we will evaluate whether any “home” isolates can outperform (or can be easily modified to outperform) an approved and commercialized biocontrol “away” Pseudomonas.

This is important because a sustainable bacterial inoculant that could be applied to Norway spruce at the seedling stage could complement existing measures and be of immense economical value to Swedish forestry.