Detection of Alternaria padwickii (Ganguly) M.B. Ellis in Rice Seeds Using Hyperspectral Imaging to Enhance Seed Health Assessment in Germplasm Exchange

The international exchange of rice germplasm is fundamental for crop improvement and production but poses risks of spreading seed-borne pathogens like Alternaria padwickii. Conventional detection methods, such as the blotter test, are effective but destructive and time-consuming. This study was cond...

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Autores principales: Cortez, Camille Rae, Castellion, Martina, Catausan, Sheryl, Gentallan, Renerio Jr., Calayugan, Mark Ian, Mercado, Ma. Fatima O., Hay, Fiona R.
Formato: Manuscript-unpublished
Lenguaje:Inglés
Publicado: International Rice Research Institute 2025
Materias:
Acceso en línea:https://hdl.handle.net/10568/180258
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author Cortez, Camille Rae
Castellion, Martina
Catausan, Sheryl
Gentallan, Renerio Jr.
Calayugan, Mark Ian
Mercado, Ma. Fatima O.
Hay, Fiona R.
author_browse Calayugan, Mark Ian
Castellion, Martina
Catausan, Sheryl
Cortez, Camille Rae
Gentallan, Renerio Jr.
Hay, Fiona R.
Mercado, Ma. Fatima O.
author_facet Cortez, Camille Rae
Castellion, Martina
Catausan, Sheryl
Gentallan, Renerio Jr.
Calayugan, Mark Ian
Mercado, Ma. Fatima O.
Hay, Fiona R.
author_sort Cortez, Camille Rae
collection Repository of Agricultural Research Outputs (CGSpace)
description The international exchange of rice germplasm is fundamental for crop improvement and production but poses risks of spreading seed-borne pathogens like Alternaria padwickii. Conventional detection methods, such as the blotter test, are effective but destructive and time-consuming. This study was conducted to investigate hyperspectral imaging (HSI) in the 400-1000 nm range as a rapid, non-destructive alternative in detecting A. padwickii in rice seeds. Initial classification models using whole-seed spectral data demonstrated high specificity but failed to achieve adequate sensitivity, as signals from localized infections were diluted by spectra of healthy tissue. Recognizing that A. padwickii infection originates at the seed tips, it was hypothesized that a targeted analysis would yield superior results. A second experiment isolated the seed tip as a specific region-of-interest (ROI). This biologically-informed strategy proved critical, filtering spectral noise and dramatically improving performance. To handle data dimensionality, spectral refinement was performed using Partial Least Squares Discriminant Analysis (PLS-DA). Based on Variable Importance in Projection (VIP) scores, the most informative wavelengths were identified for classification. This combined ROI and spectral refinement approach enabled multiple machine learning models to achieve perfect classification scores (100% sensitivity, specificity and accuracy). The models’ high accuracy was maintained even in the presence of other common seed-borne fungi, demonstrating robustness across diverse fungal conditions.  HSI, coupled with a biologically-informed ROI and targeted spectral refinement, is therefore a powerful, non-destructive tool for detecting A. padwickii. An enhanced workflow is proposed, using HSI as a high-throughput screening tool to significantly improve the efficiency in seed health testing for germplasm transboundary movement.
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spelling CGSpace1802582026-01-20T22:13:01Z Detection of Alternaria padwickii (Ganguly) M.B. Ellis in Rice Seeds Using Hyperspectral Imaging to Enhance Seed Health Assessment in Germplasm Exchange Cortez, Camille Rae Castellion, Martina Catausan, Sheryl Gentallan, Renerio Jr. Calayugan, Mark Ian Mercado, Ma. Fatima O. Hay, Fiona R. seed-borne organisms pathogens rice Alternaria fungi hyperspectral imagery seed testing phytosanitary measures machine learning The international exchange of rice germplasm is fundamental for crop improvement and production but poses risks of spreading seed-borne pathogens like Alternaria padwickii. Conventional detection methods, such as the blotter test, are effective but destructive and time-consuming. This study was conducted to investigate hyperspectral imaging (HSI) in the 400-1000 nm range as a rapid, non-destructive alternative in detecting A. padwickii in rice seeds. Initial classification models using whole-seed spectral data demonstrated high specificity but failed to achieve adequate sensitivity, as signals from localized infections were diluted by spectra of healthy tissue. Recognizing that A. padwickii infection originates at the seed tips, it was hypothesized that a targeted analysis would yield superior results. A second experiment isolated the seed tip as a specific region-of-interest (ROI). This biologically-informed strategy proved critical, filtering spectral noise and dramatically improving performance. To handle data dimensionality, spectral refinement was performed using Partial Least Squares Discriminant Analysis (PLS-DA). Based on Variable Importance in Projection (VIP) scores, the most informative wavelengths were identified for classification. This combined ROI and spectral refinement approach enabled multiple machine learning models to achieve perfect classification scores (100% sensitivity, specificity and accuracy). The models’ high accuracy was maintained even in the presence of other common seed-borne fungi, demonstrating robustness across diverse fungal conditions.  HSI, coupled with a biologically-informed ROI and targeted spectral refinement, is therefore a powerful, non-destructive tool for detecting A. padwickii. An enhanced workflow is proposed, using HSI as a high-throughput screening tool to significantly improve the efficiency in seed health testing for germplasm transboundary movement. 2025-12 2026-01-20T22:13:00Z 2026-01-20T22:13:00Z Manuscript-unpublished https://hdl.handle.net/10568/180258 en Limited Access International Rice Research Institute Cortez, Camille Rae, Martina Castellion, Sheryl Catausan, Renerio Gentallan, Jr., Mark Ian Calayugan, Ma. Fatima O. Mercado, Fiona R. Hay (2025). Detection of Alternaria padwickii (Ganguly) M.B. Ellis in Rice Seeds Using Hyperspectral Imaging to Enhance Seed Health Assessment in Germplasm Exchange. International Rice Research Institute, Los Baños, Philippines. 93 p.
spellingShingle seed-borne organisms
pathogens
rice
Alternaria
fungi
hyperspectral imagery
seed testing
phytosanitary measures
machine learning
Cortez, Camille Rae
Castellion, Martina
Catausan, Sheryl
Gentallan, Renerio Jr.
Calayugan, Mark Ian
Mercado, Ma. Fatima O.
Hay, Fiona R.
Detection of Alternaria padwickii (Ganguly) M.B. Ellis in Rice Seeds Using Hyperspectral Imaging to Enhance Seed Health Assessment in Germplasm Exchange
title Detection of Alternaria padwickii (Ganguly) M.B. Ellis in Rice Seeds Using Hyperspectral Imaging to Enhance Seed Health Assessment in Germplasm Exchange
title_full Detection of Alternaria padwickii (Ganguly) M.B. Ellis in Rice Seeds Using Hyperspectral Imaging to Enhance Seed Health Assessment in Germplasm Exchange
title_fullStr Detection of Alternaria padwickii (Ganguly) M.B. Ellis in Rice Seeds Using Hyperspectral Imaging to Enhance Seed Health Assessment in Germplasm Exchange
title_full_unstemmed Detection of Alternaria padwickii (Ganguly) M.B. Ellis in Rice Seeds Using Hyperspectral Imaging to Enhance Seed Health Assessment in Germplasm Exchange
title_short Detection of Alternaria padwickii (Ganguly) M.B. Ellis in Rice Seeds Using Hyperspectral Imaging to Enhance Seed Health Assessment in Germplasm Exchange
title_sort detection of alternaria padwickii ganguly m b ellis in rice seeds using hyperspectral imaging to enhance seed health assessment in germplasm exchange
topic seed-borne organisms
pathogens
rice
Alternaria
fungi
hyperspectral imagery
seed testing
phytosanitary measures
machine learning
url https://hdl.handle.net/10568/180258
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