Detecting asymptomatic ink-diseased chestnut trees by the composition of the ectomycorrhizal community

The research was performed in a new and isolated ink disease outbreak. Nine sweet chestnuts of comparable age, growing under same environmental and site conditions, and belonging to three phytosanitary classes (healthy, infected but asymptomatic and symptomatic) were randomly selected. Their ectomycorrhizal community was monitored during two periods, with regard to species abundance, to verify whether the community composition can be useful as an ink disease bioindicator. From the 216 samples, 29 ectomycorrhizal species were recorded, with abundances that changed with the health status of the tree. The results demonstrated that the mycorrhizal community composition was highly related to the ink disease level, allowing the consideration of the use of this parameter as a tool for the quick detection and control of the early stages of the disease.