Abstract:
Fungal communities in above-ground tree tissues are hyperdiverse and are influenced by
biotic interactions with other organisms living in or on these tissues. These biotic interactions
are, however, still poorly understood. In this study, we aimed to understand how insectassociated gall formation on Eucalyptus foliage correlates with the diversity of foliar fungal
communities in surrounding healthy leaf tissue, as well as the co-occurrence patterns
among the members of the fungal community. We used ITS metabarcoding to characterise
the foliar fungal communities of 179 individual E. grandis trees. These trees were assigned
to infestation levels of the wasp Leptocybe invasa (Eulophidae: Hymenoptera), which
causes gall formation on shoot tips and leaves of its host. Fungal community networks
were calculated using a Pearson correlation coefficient. The composition and diversity of
fungal communities were influenced by the severity of L. invasa infestations. We identified
potential Eucalyptus pathogens with high sequence abundance at all disease severity
levels, but network analysis indicated that the co-occurrence of potential pathogens
between no to mild and medium to heavy infestation differed significantly. A better
understanding of microbial interactions, especially the role of pathogens, can be useful
for controlling disease- and beneficial host-associated microbial communities.
