Plant-fungal interactions are ubiquitous. For a forest ecologist interested in how plant species are distributed, compete for resources, and defend against their natural enemies, fungi are difficult, if not impossible, to ignore. Furthermore, fungi are now known to infect all plant tissues – from their roots and sapwood to flowers, leaves and seeds. In many cases these internal infections of plants by ‘endophytic fungi’ occur either without adverse impacts on the plant host, or with impacts that vary depending on the identity of the host species.
James will review the breadth of endophytic fungal infections, and some of the impacts these have on their hosts. He will then describe the work he and his team are conducting in lowland tropical forest in Panama on the fungi that infect seeds of tree species that depend on soil seed banks to successfully regenerate after disturbance. Using a combination of carbon-dating, seed burial experiments, fungal culturing and inoculation experiments they have found a high degree of host specificity of seed fungi. These fungal infections can be viewed as the ‘primary symbionts’ that plants encounter, with impacts on seed germination and survival that are a consequence both of the fungi themselves, as well as bacteria that live within the fungal hyphae.
Understanding how seed infecting fungi impact seed survival patterns can help us understand how tropical forest diversity is maintained, and also has applications for the protection of crop seeds and the management of weed species in agricultural systems.