The spruces’ genotype determines which fungi live in and on the needles

Tree associated microbes influence host fitness. For example, the composition of fungi on and in a needle or leaf can increase the plant's stress resistance, growth and protect against pests. But what determines the composition of the microbiome? We still know very little about this, particularly for above ground tissues.

Fungal communities in spruce needles examined

In a new study, researchers from SLU with colleagues from Spain has investigated the mycobiome of Norway spruce needles.

– It turned out that the mycobiome of the needles is affected by the genotype of the tree. Genetically similar trees had similar mycobiome communities and the more genetically different the trees are, the more different fungal communities they have, says Miguel Angel Redondo, who is the study's lead author.

Climate and genotype play a greater role than tree size and health

The researchers also showed that trees recruit their fungi depending on the locally available spore pool. The climate also plays a role in fungal recruitment. Factors such as the diameter of the tree and how healthy the tree crown was were less important.

– Now we know more about the mechanisms that underlie the composition of plant mycobiomes and this provides a good basis for further studies, says Anna Berlin, another researcher behind the study.