A multiplex PCR-based method for the detection and early identification of wood rotting fungi in standing trees

Aims: The goal of this research was the development of a PCR-based assay to identify directly from wood some of the important decay fungi responsible for failures of hardwood tree species in urban environments of northern temperate regions. Methods and Results: Eleven reverse taxon-specific primers were designed for PCR amplification of either nuclear or mitochondrial ribosomal DNA regions of Armillaria spp., Ganoderma spp., Hericium spp., Hypoxylon thouarsianum var. thouarsianum, Inonotus/Phellinus-group, Laetiporus spp., Perenniporia fraxinea, Pleurotus spp., Schizophyllum spp., Stereum spp. and Trametes spp. Multiplex PCR reactions were developed and optimized to detect fungal DNA and identify each taxon with an overall sensitivity of at least one pg of DNA template. After validation on samples collected from decay-affected trees, we were able to detect the target fungal taxa in 82% of wood samples. Conclusions: The development and optimization of multiplex PCRs allowed for reliable identification of wood rotting fungi that could be rapidly and efficiently identified from wood DNA extracts. Significance and Impact of the Study: Early detection of fungi responsible for decay is crucial for assessment of tree stability in urban landscapes. Furthermore, this method may prove useful for prediction of the severity and the evolution of decay in standing trees.