Ash dieback disease (caused by Hymenoscyphus fraxineus) has affected European ash species (Fraxinus spp.) in recent decades. However, some Asian and American species of Fraxinus and certain genotypes of Fraxinus excelsior are less affected by the disease. We used ITS1-metabacoding to explore the drivers influencing diversity and composition of the twig fungal communities of Fraxinus species and F. excelsior genotypes. Our results revealed that fungi in the classes Eurotiomycetes and Dothideomycetes were among the most prevalent taxa in both Fraxinus species and F. excelsior genotypes. The diversity of the fungal communities differed significantly among Fraxinus species and could be explained by seed origin. Neither host genotype nor season had a significant effect on the community diversity of F. excelsior genotypes. On the other hand, the composition of twig fungal communities differed significantly among host species and among F. excelsior genotypes, and in F. excelsior there was also a significant effect of season on the composition of the fungal community. We did not find a clear effect of ash dieback susceptibility on either diversity or composition of fungal communities in twigs of Fraxinus species, although the effect was significant on the composition of fungal communities among F. excelsior genotypes. Our results demonstrated differences in fungal communities among species of Fraxinus and of F. excelsior genotypes, suggesting specific relationship between individual host genotypes and endophytic fungi.

近几十年来，灰烬枯死病（由Hymenoscyphus fraxineus引起）已经影响了欧洲的灰烬物种（Fraxinus spp。）。但是，某些亚洲和美洲种类的水曲柳和某些基因型的水曲柳受到的影响较小。我们使用ITS1元编码来探索驱动因子，以影响水曲柳属物种和优良种F. gensitype基因型的树枝真菌群落的多样性和组成。我们的研究结果表明，欧洲真菌类和多菌类类中的真菌在白蜡树种和优良种F.中均是最普遍的分类单元。基因型。真菌群落的多样性之间的差异显著白蜡物种，并且可以通过种源来解释。寄主基因型和季节都没有对优良木薯基因型的群落多样性产生显着影响。在另一方面，枝真菌群落的组成中宿主物种之间和不同显著F.精益求精的基因型，并在白蜡也有季节上的真菌群落的组成显著的效果。我们没有发现灰分固结敏感性对水曲柳树枝中真菌群落的多样性或组成有明显影响。物种，尽管该效果对优良种F.真菌基因型中真菌群落的组成具有显着影响。我们的研究结果表明，水曲柳属和优良种之间的真菌群落存在差异，这表明个体宿主基因型与内生真菌之间存在特定的关系。