Sherwood, Patrick
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences
Abstract
Many forest pathogens have become increasingly damaging as climate-driven stress intensifies disease outbreaks. A prominent example is Diplodia sapinea, which is causing more frequent and destructive shoot blight and dieback, particularly across northern Europe. Developing resistant planting stock is a priority, but screening currently depends on destructive inoculation assays and multi-year field trials, making the process slow and difficult to scale. This study evaluated whether a handheld Fourier-transform infrared (FT-IR) spectrometer that provides rapid and non-destructive sampling can identify constitutive chemical signatures associated with relative resistance prior to infection. FT-IR spectra were collected from needles, shoots, and stem phloem from Swedish pine families across two experimental years, followed by artificial inoculations to phenotype lesion development. A combined sparse partial least squares discriminant analysis and support vector machine workflow achieved 65-81% cross-validated accuracy in distinguishing resistant from susceptible trees, with shoot spectra consistently producing the strongest models. Principal component analysis indicated clear chemical differences between years, yet resistance-associated patterns were stable across tissues. The most frequently selected wavenumbers grouped into four biochemical domains: cell-wall polysaccharides, cellulose/hemicellulose bonding, phenolics and proteins, and aliphatic lipids/cutin, corresponding to known conifer defense pathways. These findings demonstrate that portable FT-IR spectroscopy can capture biologically meaningful variation in constitutive defense chemistry and offers a rapid, scalable approach for resistance phenotyping in Scots pine breeding programs.
Keywords
biochemical fingerprint; forest pathology; FT-IR; phenotyping; tree health
Published in
Frontiers in forests and global change
2026, volume: 9, article number: 1755489
Publisher: FRONTIERS MEDIA SA
SLU Authors
UKÄ Subject classification
Forest Science
Publication identifier
- DOI: https://doi.org/10.3389/ffgc.2026.1755489
Permanent link to this page (URI)
https://res.slu.se/id/publ/146783