Host genotype shapes the foliar fungal microbiome of Balsam                 poplar
Foliar fungal communities on plants are hyperdiverse and ubiquitous.                 While fungal endophytes in grasses may increase host fitness, their ecological roles                 in trees are much less understood. We performed a high-resolution analysis to provide                 an assessment of the potential effects of host genetic makeup over leaf associated                 fungal communities in a tree species. We investigated whether the genetic makeup of                 the host influences community structure of foliar fungi. We sampled leaves from                 genotyped balsam poplars from across the range grown in a common garden, and applied                 454 amplicon sequencing to characterize foliar fungal communities. We found diverse                 fungal communities in the poplar leaves. Our data suggests that host genotypes have                 a structuring effect on the composition of these communities. The observed patterns                 may be explained by a filtering mechanism by which the trees “recruit” fungal                 strains from the environment. Alternatively, hosts may be systemically infected by                 fungi, and preserve characteristic communities even after two clonal reproductions.                 Our findings suggest an intimate, non-incidental relationship between tree genotypes                 and their foliar fungi. As balsam poplar colonized its current range within the past                 18,000 years, our study suggests that foliar fungal-plant relationships may form                 within short geological timeframes.