Point-of-care diagnostics and resistance phenotyping to combat ash dieback
Data files
May 22, 2025 version files 5.24 MB
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OneDrive_1_5-1-2025.zip
5.23 MB
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README.md
1.97 KB
Abstract
Non-destructive tree phenotyping for resistance screening and early, presymptomatic disease detection figure prominently among the most important practical limitations inherent in forest health management. The need for point-of-care tools is particularly acute for managing diseases caused by non-native pathogens, often resulting in difficult-to-control biological invasions. One such case is represented by ash dieback in Europe, caused by Hymenoscyphus fraxineus, which has led Sweden to red-list its main host, European ash (Fraxinus excelsior). We evaluated the use of near-infrared (NIR) spectroscopy and machine learning for the detection of presymptomatic infections by H. fraxineus and the identification of disease-resistant European ash accessions. Here, we show that presymptomatic infected trees can be distinguished from pathogen-free trees with a testing error rate of 0.161 in a controlled inoculation experiment. We also show that the same approach can be used to identify disease-resistant European ash accessions based on data from two independent, multi-year clonal trials, with a testing error rate of 0.155. These results confirm that NIR spectroscopy combined with machine learning is sensitive enough for early disease detection and resistance screening in this system. This is consistent with prior findings in other tree-pathosystems and suggests that this approach could be developed into an operational tool to facilitate the management of biological invasions of forest environments by non-native pathogens, including habitat restoration with resistant germplasm.
Early, non-destructive detection of disease and resistance is vital for managing invasive forest pathogens like Hymenoscyphus fraxineus, the cause of ash dieback. Using NIR spectroscopy and machine learning, we identified presymptomatic infections and resistant European ash with low error rates (0.161 and 0.155). This approach shows strong potential for forest disease management and restoration.
Description of the data and file structure
- euro_ash_nir_analysis.rmd: R markdown file with all R scripts for analysis of spectral data
- Snogeholm_June2023.csv: csv file with raw spectral data from the Snogeholm study site.
sample_name: spectral file identifier
tree: unique tree ID
rep: technical replicate; technical replicates from each tree were averaged before analysis
phenotype: disease phenotype, resistant or susceptible
remaining columns: reflectance values for wavenumbers, from 3922 - 7407 cm-1
- Alnarp_July2023.csv: csv file with raw spectra data from the Alnarp study site.
sample_name: spectral file identifier
tree: unique tree id
rep: technical replicate; technical replicates from each tree were averagedbeforeo analysis
phenotype: disease phenotype, resistant or susceptible
- Trolleholm_data.xlsx: xlsx file with raw spectral data from Trolleholm study site.
Sample Name: spectral file identifier
tree: unique tree id
clone: clone id
rep: technical replicate; technical replicates from each tree were averagedbeforeo analysis
phenotype: disease phenotype, resistant or susceptible
- biotron_all.csv: csv file with raw spectral data from the Biotron study.
sample_name: spectral file identifier
tree: unique tree id
rep: technical replicate; technical replicates from each tree were averagedbeforeo analysis
treatment: treatment, I-inoculated or C-control
time: time point, 0-time 0 or 1-time 1
