Phytophthora hibernalis, P. lacustris and P. multivora associated with declining Ligustrum lucidum trees in an urban park in Portugal
Author(s)
Date Issued
2025
Type
article
Journal
Abstract
During a monitoring survey carried out in a park in Aveiro, Portugal, typical
Phytophthora symptoms of root rot, stem bleeding cankers and extensive canopy
dieback were observed on mature ornamental glossy privet trees (Ligustrum lucidum).
A study carried out in spring 2022 aimed to isolate the causal agents, as there is was no
available knowledge on potential root pathogens of this host. Thirty-two Phytophthora
isolates were obtained from inner bark tissues and/or rhizosphere samples (soil and
fine roots) collected from 27 declining glossy privet trees. Based on morpho-biometric
data and phylogeny of concatenated ITS and cox1 sequences, Phytophthora isolates
were identified as P. hibernalis (14 isolates), P. multivora (12) and P. lacustris (6). Pathogenicity
tests confirmed the virulence of the three species on glossy privet. Phytophthora
lacustris was the most aggressive species, while P. hibernalis was most abundant.
These results give new insights into emerging Phytophthora-related tree diseases in
urban areas, and highlight the importance of enhancing biosecurity measures against
these invasive pathogens.